conjugated estrogens (Rx)

Brand and Other Names:Premarin
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 0.3mg
  • 0.45mg
  • 0.625mg
  • 0.9mg
  • 1.25mg

powder for injection

  • 25mg

Menopausal Vasomotor Symptoms, Atrophic Vaginitis/Kraurosis Vulvae

0.3 mg PO once daily in either continuous daily regimen or cyclic regimen (25 days on, 5 days off); adjusted PRN; use lowest dose that control symptoms; may be given daily if medical assessment warrants it

Female Hypogonadism

0.3-0.625 mg PO once daily in cyclic regimen (3 weeks on, 1 week off); may be titrated every 6-12 months; adjusted PRN; add progestin treatment should be added to maintain bone mineral density once skeletal maturity achieved

Osteoporosis

Prophylaxis

0.3 mg PO once daily in cyclic regimen (25 days on, 5 days off); adjusted PRN based on clinical response; may be given daily if medical assessment warrants it; administer lowest effective dose

May also be used in combination with medroxyprogesterone acetate

Prostate Cancer

Palliation only

1.25-2.5 mg PO q8hr

Abnormal Uterine Bleeding

25 mg IV/IM; repeated in 6-12 hours PRN or 25 mg IV repeated q4hr for 24 hr; if no response after 2 doses, re-evaluate therapy

Alternative regimen: 10-20 mg/day PO divided q4hr

May administer low dose medroxyprogesterone acetate with therapy or following therapy

Cyclic therapy: 25 days on, 5 days off; either 3 weeks on, 1 week off

Female Castration/Primary Ovarian Failure

1.25 mg PO once daily in cyclic regimen (25 days on, 5 days off); adjusted PRN; administer lowest effective dose

Breast Cancer Palliation

Metastatic disease in selected patients (males and females):10 mg PO q8hr for ≥3 months

Uremic Bleeding (Off-label)

0.6 mg/kg/day IV for 5 days

Safety and efficacy not established

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Interactions

Interaction Checker

and conjugated estrogens

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            Contraindicated (1)

            • ospemifene

              ospemifene, conjugated estrogens. Either increases effects of the other by pharmacodynamic synergism. Contraindicated.

            Serious - Use Alternative (39)

            • abametapir

              abametapir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

              abametapir will increase the level or effect of conjugated estrogens by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.

            • anastrozole

              conjugated estrogens decreases effects of anastrozole by pharmacodynamic antagonism. Contraindicated.

            • antithrombin alfa

              conjugated estrogens decreases effects of antithrombin alfa by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • antithrombin III

              conjugated estrogens decreases effects of antithrombin III by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • apalutamide

              apalutamide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • argatroban

              conjugated estrogens decreases effects of argatroban by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • bemiparin

              conjugated estrogens decreases effects of bemiparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • bivalirudin

              conjugated estrogens decreases effects of bivalirudin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • carbamazepine

              carbamazepine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • cimetidine

              cimetidine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • clarithromycin

              clarithromycin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • dabrafenib

              dabrafenib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • dalteparin

              conjugated estrogens decreases effects of dalteparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • darunavir

              darunavir will decrease the level or effect of conjugated estrogens by unspecified interaction mechanism. Avoid or Use Alternate Drug.

            • enoxaparin

              conjugated estrogens decreases effects of enoxaparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • enzalutamide

              enzalutamide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin base

              erythromycin base will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin ethylsuccinate

              erythromycin ethylsuccinate will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin lactobionate

              erythromycin lactobionate will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin stearate

              erythromycin stearate will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • fexinidazole

              fexinidazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

            • fondaparinux

              conjugated estrogens decreases effects of fondaparinux by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • givosiran

              givosiran will increase the level or effect of conjugated estrogens by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.

            • heparin

              conjugated estrogens decreases effects of heparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • idelalisib

              idelalisib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

            • itraconazole

              itraconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ketoconazole

              ketoconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lorlatinib

              lorlatinib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • mitotane

              mitotane will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • nefazodone

              nefazodone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • phenindione

              conjugated estrogens decreases effects of phenindione by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • pretomanid

              pretomanid will increase the level or effect of conjugated estrogens by Other (see comment). Avoid or Use Alternate Drug. In vitro studies demonstrated that pretomanid significantly inhibits OAT3; monitor for increased adverse effects and consider dosage reduction for OAT3 substrates.

            • protamine

              conjugated estrogens decreases effects of protamine by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            • quinidine

              quinidine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

            • rifabutin

              rifabutin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • rifampin

              rifampin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • St John's Wort

              St John's Wort will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tucatinib

              tucatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

            • warfarin

              conjugated estrogens decreases effects of warfarin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.

            Monitor Closely (159)

            • albiglutide

              conjugated estrogens decreases effects of albiglutide by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.

            • ambrisentan

              ambrisentan will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              ambrisentan will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • amikacin

              amikacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • amiodarone

              amiodarone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • amobarbital

              amobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • aprepitant

              aprepitant will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • armodafinil

              armodafinil will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • artemether/lumefantrine

              artemether/lumefantrine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • atazanavir

              atazanavir, conjugated estrogens. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Atazanavir may increase or decrease levels of estrogens conjugated . Use alternatives if available.

            • atogepant

              conjugated estrogens will decrease the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • atorvastatin

              atorvastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • axitinib

              conjugated estrogens decreases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • azithromycin

              azithromycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

            • aztreonam

              aztreonam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • bosentan

              bosentan will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • budesonide

              budesonide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • butabarbital

              butabarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • butalbital

              butalbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cannabidiol

              cannabidiol, conjugated estrogens. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.

            • cefadroxil

              cefadroxil will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • cefamandole

              cefamandole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • cefpirome

              cefpirome will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • cenobamate

              cenobamate will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

            • cephalexin

              cephalexin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • chlorhexidine oral

              chlorhexidine oral will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • ciprofloxacin

              ciprofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • clarithromycin

              clarithromycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

              clarithromycin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • clindamycin

              clindamycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • clotrimazole

              clotrimazole will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • conivaptan

              conivaptan will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cortisone

              cortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • crofelemer

              crofelemer increases levels of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 and transporters MRP2 and OATP1A2 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

            • cyclosporine

              cyclosporine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              cyclosporine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              cyclosporine will increase the level or effect of conjugated estrogens by Other (see comment). Use Caution/Monitor. may increase plasma concentrations of organic anion transporter protein substrates

            • dapsone

              dapsone will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • darifenacin

              darifenacin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dasatinib

              dasatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • deferasirox

              deferasirox will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • demeclocycline

              demeclocycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • dexamethasone

              dexamethasone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • DHEA, herbal

              DHEA, herbal will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • diltiazem

              diltiazem will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • doxycycline

              doxycycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • dronedarone

              dronedarone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              dronedarone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • efavirenz

              efavirenz will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • eluxadoline

              eluxadoline increases levels of conjugated estrogens by decreasing metabolism. Use Caution/Monitor. Eluxadoline may increase the systemic exposure of coadministered OATP1B1 substrates.

            • encorafenib

              encorafenib, conjugated estrogens. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

            • ertapenem

              ertapenem will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • erythromycin base

              erythromycin base will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

              erythromycin base will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • erythromycin ethylsuccinate

              erythromycin ethylsuccinate will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

              erythromycin ethylsuccinate will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • erythromycin lactobionate

              erythromycin lactobionate will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

              erythromycin lactobionate will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • erythromycin stearate

              erythromycin stearate will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

              erythromycin stearate will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • eslicarbazepine acetate

              eslicarbazepine acetate will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • etravirine

              etravirine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • exenatide injectable solution

              conjugated estrogens decreases effects of exenatide injectable solution by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.

            • exenatide injectable suspension

              conjugated estrogens decreases effects of exenatide injectable suspension by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.

            • fedratinib

              fedratinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

            • felodipine

              felodipine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • fleroxacin

              fleroxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • fluconazole

              fluconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fludrocortisone

              fludrocortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fosamprenavir

              fosamprenavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fosfomycin

              fosfomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • fosphenytoin

              fosphenytoin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              fosphenytoin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • gemifloxacin

              gemifloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • gentamicin

              gentamicin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • grapefruit

              grapefruit will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • griseofulvin

              griseofulvin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • hemin

              conjugated estrogens decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.

            • hyaluronidase

              conjugated estrogens decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Enhanced tissue resistance to hyaluronidase.

            • hydrocortisone

              hydrocortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • indinavir

              indinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              indinavir will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • insulin degludec

              conjugated estrogens decreases effects of insulin degludec by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.

            • insulin degludec/insulin aspart

              conjugated estrogens decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.

            • insulin inhaled

              conjugated estrogens decreases effects of insulin inhaled by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.

            • isavuconazonium sulfate

              conjugated estrogens will decrease the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • istradefylline

              istradefylline will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

            • ivosidenib

              ivosidenib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ketoconazole

              ketoconazole will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • lamotrigine

              conjugated estrogens decreases levels of lamotrigine by increasing hepatic clearance. Use Caution/Monitor.

            • lapatinib

              lapatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              lapatinib will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • levofloxacin

              levofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • linezolid

              linezolid will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • liraglutide

              conjugated estrogens decreases effects of liraglutide by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.

            • lopinavir

              lopinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • loratadine

              loratadine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • lovastatin

              lovastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • lumefantrine

              lumefantrine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • maraviroc

              conjugated estrogens increases levels of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

            • marijuana

              marijuana will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • meropenem

              meropenem will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • meropenem/vaborbactam

              meropenem/vaborbactam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • metformin

              conjugated estrogens decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor.

            • methylprednisolone

              methylprednisolone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • metronidazole

              metronidazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              metronidazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • miconazole vaginal

              miconazole vaginal will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • mifepristone

              mifepristone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • minocycline

              minocycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • modafinil

              modafinil will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • moxifloxacin

              moxifloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • nefazodone

              nefazodone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • nelfinavir

              nelfinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • neomycin PO

              neomycin PO will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • nevirapine

              nevirapine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nicardipine

              nicardipine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • nifedipine

              nifedipine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              nifedipine will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • nilotinib

              nilotinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              nilotinib will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • nitrofurantoin

              nitrofurantoin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • ofloxacin

              ofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • oxcarbazepine

              oxcarbazepine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • oxytetracycline

              oxytetracycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • paromomycin

              paromomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • pentobarbital

              pentobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • phenobarbital

              phenobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              phenobarbital will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • phenytoin

              phenytoin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              phenytoin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. If the estrogen is being used for contraception then loss of contraception may occur.

            • pivmecillinam

              pivmecillinam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • posaconazole

              posaconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • prednisone

              prednisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • primidone

              primidone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • quercetin

              quercetin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • quinupristin/dalfopristin

              quinupristin/dalfopristin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              quinupristin/dalfopristin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ranolazine

              ranolazine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • ribociclib

              ribociclib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rifampin

              rifampin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • rifapentine

              rifapentine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ritonavir

              ritonavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              ritonavir will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • roxithromycin

              roxithromycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.

            • rufinamide

              rufinamide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • saquinavir

              saquinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • secobarbital

              secobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • simvastatin

              simvastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • sirolimus

              sirolimus will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • somapacitan

              conjugated estrogens decreases effects of somapacitan by Other (see comment). Modify Therapy/Monitor Closely. Comment: Oral estrogens may reduce the serum IGF-1 response to somapacitan. Patients may require higher somapacitan dosages. See drug monograph for starting dose recommendations.

            • St John's Wort

              St John's Wort will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • stiripentol

              stiripentol, conjugated estrogens. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.

            • streptomycin

              streptomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • sulfadiazine

              sulfadiazine will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • sulfamethoxazole

              sulfamethoxazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • sulfisoxazole

              sulfisoxazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • tacrolimus

              tacrolimus will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • tazemetostat

              conjugated estrogens will decrease the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tecovirimat

              tecovirimat will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

            • teicoplanin

              teicoplanin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • temocillin

              temocillin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • teniposide

              teniposide will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • tesamorelin

              tesamorelin will decrease the level or effect of conjugated estrogens by altering metabolism. Use Caution/Monitor. May decrease efficacy; monitor

            • tetracycline

              tetracycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • ticarcillin

              ticarcillin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • tigecycline

              tigecycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • tobramycin

              tobramycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • tolvaptan

              tolvaptan will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • topiramate

              topiramate will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • trazodone

              trazodone will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • trimethoprim

              trimethoprim will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • ubrogepant

              conjugated estrogens will decrease the level or effect of ubrogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Dose adjustment is recommended with concomitant use of ubrogepant and moderate and weak CYP3A4 inducers. (see Dosage Modifications)

            • valproic acid

              conjugated estrogens will decrease the level or effect of valproic acid by increasing elimination. Modify Therapy/Monitor Closely. May lead to increased seizure frequency

            • vancomycin

              vancomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

            • verapamil

              verapamil will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              verapamil will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

            • voriconazole

              voriconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • zafirlukast

              zafirlukast will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            Minor (35)

            • amitriptyline

              conjugated estrogens, amitriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • amoxapine

              conjugated estrogens, amoxapine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • androstenedione

              androstenedione increases effects of conjugated estrogens by pharmacodynamic synergism. Minor/Significance Unknown.

            • ascorbic acid

              conjugated estrogens decreases levels of ascorbic acid by increasing elimination. Minor/Significance Unknown.

            • boron

              boron increases levels of conjugated estrogens by altering metabolism. Minor/Significance Unknown.

            • clomipramine

              conjugated estrogens, clomipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • cyanocobalamin

              conjugated estrogens decreases levels of cyanocobalamin by altering metabolism. Minor/Significance Unknown.

            • desipramine

              conjugated estrogens, desipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • dosulepin

              conjugated estrogens, dosulepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • doxepin

              conjugated estrogens, doxepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • exemestane

              conjugated estrogens decreases levels of exemestane by increasing metabolism. Minor/Significance Unknown.

            • folic acid

              conjugated estrogens decreases levels of folic acid by altering metabolism. Minor/Significance Unknown.

            • imipramine

              conjugated estrogens, imipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • isoniazid

              isoniazid will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • L-methylfolate

              conjugated estrogens decreases levels of L-methylfolate by altering metabolism. Minor/Significance Unknown.

            • lofepramine

              conjugated estrogens, lofepramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • magnesium chloride

              conjugated estrogens decreases levels of magnesium chloride by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • magnesium citrate

              conjugated estrogens decreases levels of magnesium citrate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • magnesium hydroxide

              conjugated estrogens decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • magnesium oxide

              conjugated estrogens decreases levels of magnesium oxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • magnesium sulfate

              conjugated estrogens decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • maprotiline

              conjugated estrogens, maprotiline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • metyrapone

              conjugated estrogens decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.

            • mycophenolate

              mycophenolate decreases effects of conjugated estrogens by unknown mechanism. Minor/Significance Unknown. Clinical significance unclear.

            • nortriptyline

              conjugated estrogens, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • phytoestrogens

              phytoestrogens decreases effects of conjugated estrogens by pharmacodynamic antagonism. Minor/Significance Unknown.

            • pleurisy root

              pleurisy root decreases effects of conjugated estrogens by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.

            • progesterone, natural

              progesterone, natural, conjugated estrogens. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Combination may produce breast tenderness.

            • protriptyline

              conjugated estrogens, protriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • pyridoxine

              conjugated estrogens decreases levels of pyridoxine by altering metabolism. Minor/Significance Unknown.

            • pyridoxine (Antidote)

              conjugated estrogens decreases levels of pyridoxine (Antidote) by altering metabolism. Minor/Significance Unknown.

            • ropinirole

              conjugated estrogens increases levels of ropinirole by unspecified interaction mechanism. Minor/Significance Unknown.

            • rose hips

              conjugated estrogens decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.

            • trazodone

              conjugated estrogens, trazodone. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

            • trimipramine

              conjugated estrogens, trimipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.

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            Adverse Effects

            >10%

            Abdominal pain (15-17%)

            Back pain (13-14%)

            Breast enlargement

            Breast tenderness (7-12%)

            Headache (26-32%)

            Arthralgia (7-14%)

            Pharyngitis (10-12%)

            Sinusitis (6-11%)

            Diarrhea (6-7%)

            1-10%

            Depression (5-8%)

            Dizziness (4-6%)

            Nervousness (2-5%)

            Flatulence (6-7%)

            Vaginitis (5-7%)

            Leukorrhea (4-7%)

            Leg cramps (3-7%)

            Increased cough (4-7%)

            Pruritus (4-5%)

            Frequency Not Defined

            Amenorrhea

            Breakthrough bleeding

            Corneal curvation change

            Melasma

            Spotting

            Vaginal moniliasis

            Weight changes

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            Warnings

            Black Box Warnings

            Estrogens increase risk of endometrial cancer

            • Close clinical surveillance of all women taking estrogens is important
            • Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding
            • There is no evidence that the use of "natural" estrogens results in a different endometrial risk profile than the use of synthetic estrogens at equivalent estrogen doses

            Increased risk of breast cancer

            • Using conjugated estrogens in combination with medroxyprogesterone increases risk of invasive breast cancer

            Cardiovascular risks

            • Estrogens with or without progestins should not be used to prevent cardiovascular disease
            • Estrogens plus progestins: Women’s Health Initiative (WHI) Estrogen Plus Progestin substudy reported increased risks of myocardial infarction (MI), stroke, invasive breast cancer, pulmonary embolism (PE), and deep vein thrombosis (DVT) in postmenopausal women (aged 50-79 years) during 5.6 years of treatment with daily PO conjugated estrogens (0.625 mg) combined with medroxyprogesterone acetate (2.5 mg) in comparison with placebo
            • Estrogens alone: A substudy of the WHI study reported increased risk for stroke and DVT in postmenopausal women (aged 50-79 years) during 6.8 years of treatment with daily PO conjugated estrogens (0.625 mg) alone in comparison with placebo

            Dementia risks

            • Estrogens with or without progestins should not be used to prevent dementia
            • Women's Health Initiative Memory Study (WHIMS), a substudy of the WHI study, reported increased risk of developing probable dementia in postmenopausal women aged ≥65 years during 4 years of treatment with daily PO conjugated estrogens (0.625) mg combined with medroxyprogesterone acetate (2.5 mg) in comparison with placebo
            • Estrogens alone: A substudy of the WHIMS reported increased risk of developing probable dementia in postmenopausal women aged ≥65 years during 5.2 years of treatment with daily PO conjugated estrogens (0.625 mg) alone in comparison with placebo
            • Unknown whether these findings apply to younger postmenopausal women

            Dose & duration

            • In the absence of comparable data, these risks should be assumed to be similar for other doses of conjugated estrogens and medroxyprogesterone acetate, as well as for other combinations and dosage forms of estrogens and progestins
            • Because of these risks, estrogens with or without progestins should be prescribed at the lowest effective dosage and for the shortest duration consistent with treatment goals and individual risks

            Contraindications

            Known anaphylactic reaction or angioedema

            Known protein C, protein S, or antithrombin deficiency; other known thrombophilic disorders

            Active or history of breast cancer

            Arterial thromboembolic disease (stroke, MI), thrombophlebitis, DVT/PE, thrombogenic valvular disease

            Liver disease, liver tumors

            Uncontrolled hypertension, diabetes mellitus with vascular involvement, jaundice with previous oral contraceptive use

            Estrogen-dependent neoplasia

            Undiagnosed abnormal vaginal bleeding

            Cautions

            Use caution in diabetes mellitus, hyperlipidemias, hypertension, hypothyroidism, advanced age, hepatic or renal impairment, uterine leiomyomata, porphyria, patients with defects of lipoprotein metabolism, hypertriglyceridemia, ovarian cancer, systemic lupus erhythematosus, exacerbation of endometriosis or other conditions, smoking, diseases exacerbated by fluid retention

            Manage appropriately risk factors for arterial vascular disease (e.g., hypertension, diabetes mellitus, tobacco use, hypercholesterolemia, and obesity) and/or venous thromboembolism (e.g., personal history or family history of VTE, obesity, and systemic lupus erythematosus)

            In patients with pre-existing hypertriglyceridemia, estrogen therapy may be associated with elevations of plasma triglycerides leading to pancreatitis and other complications

            Estrogens may be poorly metabolized in patients with impaired liver function; exercise caution in patients with a history of cholestatic jaundice associated with past estrogen use or with pregnancy; in the case of recurrence, discontinue medication

            Patients dependent on thyroid hormone replacement therapy who are also receiving estrogens may require increased doses of thyroid replacement therapy; these patients should have their thyroid function monitored in order to maintain their free thyroid hormone levels in an acceptable range

            A 2 to 4-fold increase in risk of gallbladder disease requiring surgery in postmenopausal women receiving estrogens reported

            Retinal vascular thrombosis reported in patients receiving estrogens; discontinue medication pending examination if there is sudden partial or complete loss of vision, or a sudden onset of proptosis, diplopia, or migraine; if examination reveals papilledema or retinal vascular lesions, estrogens should be discontinued

            There are, possible risks that may be associated with use of progestins with estrogens compared to estrogen-alone regimens, including a possible increased risk of breast cancer, adverse effects on lipoprotein metabolism (e.g., lowering HDL, raising LDL), and impairment of glucose tolerance

            Discontinue if any of the following develop: Jaundice, signs of venous thromboembolism, visual problems (may cause contact lens intolerance), massive blood pressure increase, major surgery or prolonged immobilization occurring in 4 weeks, new migraine, depression

            Women with protein C or S deficiency (inherited thrombophilia), may have increased risk of venous thromboembolism

            Do not use with conditions that predispose to hyperkalemia

            Conditions exacerbated by fluid retention (asthma, epilepsy, migraines, cardiac or renal dysfunction)

            Risk of hypercalcemia in patients with breast cancer and bone metastases

            Increased risk of ovarian and endometrial cancer reported in women who used hormonal therapy for menopausal symptoms

            Long-term postmenopausal estrogen treatment has been associated with increased risk of breast cancer, MI, stroke, DVT/PE, and dementia

            Patients on warfarin or other oral anticoagulants: Estrogens increase thromboembolic risk; increase in anticoagulant dosage may be warranted

            Discontinue therapy if pancreatitis occurs; estrogen compounds generally associated with increased triglyceride levels

            Cases of anaphylaxis and angioedema have been reported; exogenous estrogens may exacerbate symptoms of angioedema in women with hereditary angioedema

            Use caution in individuals with severe hypocalcemia

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            Pregnancy & Lactation

            Pregnancy category: X

            Lactation: Use controversial; estrogens are excreted into breast milk in small quantities; use with caution

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

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            Pharmacology

            Mechanism of Action

            Replaces endogenous estrogen; important for development and maintenance of female reproductive system and secondary sexual characteristics

            Antiandrogenic effect provides benefit in prostate cancer

            Absorption

            Bioavailability: Readily absorbed from gastrointestinal (GI) tract

            Onset: 2-4 weeks (PO-menopause)

            Peak plasma time: 7 hr (PO)

            Distribution

            Protein bound: 80%

            Metabolism

            Metabolized in liver to inactive sulfates and glucuronides

            Metabolites: Estradiol, estrone, estriol

            Elimination

            Excretion: Mainly in urine as conjugates with small amount of unchanged drug; most estrogens are also excreted in bile and undergo enterohepatic recycling

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            Administration

            IV Incompatibilities

            Additive, syringe, Y-site: Ascorbic acid, acidic solutions, protein hydrolysate

            IV Compatibilities

            Solution: D5W, NS, invert sugar solutions

            Y-site: Heparin/hydrocortisone, potassium chloride, vitamins B and C

            IV Preparation

            Reconstitute with 5 mL of diluent provided

            First withdraw air from vial, then add diluent slowly and aseptically with gentle agitation

            Stable at 2-8°C for 60 days

            Do not use if agent darkens or precipitates

            IV/IM Administration

            IM: Acceptable

            IV: Administer slowly to avoid flushing reaction

            Infusion not recommended; injection into running infusion can be performed

            Storage

            Refrigerate reconstituted injection

            Intact vials are stable for 24 months at room temperature

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            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            Premarin injection
            -
            25 mg vial
            Premarin vaginal
            -
            0.625 mg/gram cream
            Premarin oral
            -
            0.625 mg tablet
            Premarin oral
            -
            1.25 mg tablet
            Premarin oral
            -
            0.625 mg tablet
            Premarin oral
            -
            0.3 mg tablet
            Premarin oral
            -
            0.45 mg tablet
            Premarin oral
            -
            0.9 mg tablet

            Copyright © 2010 First DataBank, Inc.

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            Patient Handout

            Select a drug:
            Patient Education
            conjugated estrogens injection

            NO MONOGRAPH AVAILABLE AT THIS TIME

            USES: Consult your pharmacist.

            HOW TO USE: Consult your pharmacist.

            SIDE EFFECTS: Consult your pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: Consult your pharmacist.

            DRUG INTERACTIONS: Consult your pharmacist.Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

            OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

            NOTES: No monograph available at this time.

            MISSED DOSE: Consult your pharmacist.

            STORAGE: Consult your pharmacist.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

            Information last revised July 2016. Copyright(c) 2021 First Databank, Inc.

            IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

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            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

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            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
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            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.