neomycin PO (Rx)

Brand and Other Names:Neo-Fradin, Myciguent, more...Mycifradin
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Dosing & Uses


Dosage Forms & Strengths


  • 500mg

oral solution

  • 25mg/mL

Pre-Op Intestinal Antisepsis

1 g PO at 19, 18, and 9 hours pre-op OR

1 g PO q1hr for 4 doses, THEN 1 g q4hr to complete 24 hours of dosing OR

88 mg/kg/day divided PO q4hr for 2-3 days pre-op  

Maximum: Up to 12 grams 24 to 48 hours prior to surgery

Hepatic Encephalopathy

Acute: 4-12 g/day PO divided q6hr for 5-6 days OR 3-6 g/day for 1-2 weeks

Chronic: Up to 4 g/day PO

Diarrhea Caused by Enteropathogenic E.coli

3 g/day PO divided q6hr

Other Indications & Uses

Off-label: reduce LDL

Dosage Forms & Strengths


  • 500mg

oral solution

  • 25mg/mL


Diarrhea, preterm & newborns: 50 mg/kg/day PO divided q6hr  


Hepatic encephalopathy: 50-100 mg/kg/day PO divided q8hr for 5-6 days, no more than 12 g/24 hours  

Bowel prep: 90 mg/kg/day PO divided q4hr for 2-3 days

Diarrhea caused by enteropathogenic E.coli: 50mg/kg/day PO divided q6hr for 2-3days



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            Adverse Effects




            Irritation or soreness of mouth or rectal area

            Contact dermatitis (topical)






            Ototoxicity (auditory, vestibular)



            Black Box Warnings

            Patients treated with neomycin should be under close clinical observation because of potential toxicity associated with use

            Neurotoxicity, including ototoxicity, and nephrotoxicity following oral use reported even when used in recommended doses; risk greater in patients with impaired renal function

            Potential for nephrotoxicity, permanent bilateral auditory and vestibular ototoxicity, can occur in patients with preexisting renal damage and in patients with normal renal function even when treated at higher doses and/or for periods longer than those recommended

            High-frequency deafness usually occurs first and can be detected only by audiometric testing; perform serial vestibular, and audiometric tests,as well as tests of renal function, especially in high risk patients

            Ototoxicity is often delayed in onset and patients developing cochlear damage will not have symptoms during therapy to warn them of developing eighth nerve destruction and total or partial deafness may occur long after neomycin has been discontinued

            Neuromuscular blockade and respiratory paralysis have been reported following parenteral injection, topical instillation (as in orthopedic and abdominal irrigation or in local treatment of empyema), and oral use of aminoglycosides, especially when given soon after anesthesia or muscle relaxants. If blockage occurs, calcium salts may reverse these phenomena, but mechanical respiratory assistance may be necessary

            Avoid concurrent or sequential use of neurotoxic and/or nephrotoxic drugs including other aminoglycosides (eg, amikacin, streptomycin, neomycin, kanamycin, gentamicin, paromomycin

            Cumulative listing of drugs to avoid from all aminoglycoside package inserts includes amphotericin B, bacitracin, cephaloridine, cisplatin, colistin, polymixin B, vancomycin, and viomycin. Avoid potent diuretics (eg, ethacrynic acid, furosemide) because they increase risk of ototoxicity. When administered intravenously, diuretics may enhance aminoglycoside toxicity by altering antibiotic concentrations in serum and tissue

            Other factors which increase risk of toxicity are advanced age and dehydration

            Avoid concurrent use of neomycin with potent diuretics such as ethacrynic acid or furosemide; certain diuretics by themselves may cause ototoxicity; when administered intravenously, diuretics may enhance neomycin toxicity by altering antibiotic concentration in serum and tissue



            Patients with a history of hypersensitivity or serious toxic reactions to other aminoglycosides

            Patients with inflammatory or ulcerative gastrointestinal disease


            Potential for enhanced gastrointestinal absorption of neomycin in patients with inflammatory or ulcerative gastrointestinal disease; use is contraindicated

            Rsk of hearing loss continues after drug withdrawal

            Aminoglycoside antibiotics cross placenta; there have been several reports of total irreversible bilateral congenital deafness in children whose mothers received streptomycin during pregnancy

            Prescribing this antibiotic in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to patient and increases risk of development of drug-resistant bacteria

            Use of this drug may result in overgrowth of non-susceptible organisms, particularly fungi; if this occurs, appropriate therapy should be instituted

            Neomycin is quickly and almost totally absorbed from body surfaces (except the urinary bladder) after local irrigation and when applied topically in association with surgical procedures

            Delayed-onset, irreversible deafness, renal failure, and death due to neuromuscular blockade (regardless of status of renal function) reported following irrigation of both small and large surgical fields with minute quantities of neomycin

            Cross-allergenicity among aminoglycosides has been demonstrated; aminoglycosides should be used with caution in patients with muscular disorders such as myasthenia gravis or parkinsonism since these drugs may aggravate muscle weakness because of their potential curare-like effect on neuromuscular junction

            Small amounts of orally administered neomycin are absorbed through intact intestinal mucosa; there have been many reports in the literature of nephrotoxicity and/or ototoxicity with oral use of neomycin

            If renal insufficiency develops during oral therapy, consider reducing the drug dosage or discontinuing therapy

            An oral neomycin dose of 12 g/day produces malabsorption syndrome for various substances including fat, nitrogen, cholesterol, carotene, glucose, xylose, lactose, sodium, calcium, cyanocobalamin, and iron.

            Orally administered neomycin increases fecal bile acid excretion and reduces intestinal lactase activity


            Pregnancy & Lactation


            Although serious side effects to fetus or newborn have not been reported in treatment of pregnant women with other aminoglycosides, potential for harm exists

            Animal data

            • Animal reproduction studies not conducted; if this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus


            Not known whether neomycin is excreted in human milk but shown to be excreted in cow milk following a single intramuscular injection; other aminoglycosides have been shown to be excreted in human milk

            Because of potential for serious adverse reactions from aminoglycosides in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account importance of drug to mother

            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.



            Half Life: 3 hr

            Peak Plasma Time: oral: 1-4 hr; IM ~2 hr

            Absorption: oral, percutaneous: poor (3%)

            Vd: 0.36 L/kg

            Metabolism: slightly hepatic


            Feces: 97% of oral dose as unchanged drug

            Urine: 30-50% of absorbed drug as unchanged drug

            Mechanism of Action

            Interferes with bacterial protein synthesis by binding to 30S ribosomal subunits, thus reducing the number of ammonia-producing bacteria in the intestine



            neomycin oral
            500 mg tablet
            neomycin oral
            500 mg tablet
            neomycin oral
            500 mg tablet
            neomycin oral
            500 mg tablet

            Copyright © 2010 First DataBank, Inc.


            Patient Handout

            Patient Education
            neomycin oral



            COMMON BRAND NAME(S): Mycifradin

            WARNING: This medication can rarely cause serious kidney problems and nerve damage, resulting in permanent hearing loss (including deafness or decreased hearing) and balance problems. These serious side effects may occur even in people without kidney problems and taking usual doses. Hearing problems may occur long after neomycin has been stopped. The risk is increased if you are older, already have kidney disease, or if you have a severe loss of body water (dehydration). Your risk is also increased if you receive high doses, or with longer use of this medication.Tell your doctor right away if you notice ringing/roaring sounds in the ears, hearing loss, dizziness, or an unusual decrease in the amount of your urine.Severe muscle and breathing problems may also rarely occur.Careful monitoring by your doctor will reduce the risk of these side effects. Monitoring may include hearing, kidney, and urine tests.Avoid other medications that may increase your risk for these serious side effects if taken together with neomycin. See also Drug Interactions section.

            USES: This medication is used to decrease the risk of infection after certain intestinal surgeries. Neomycin belongs to a class of drugs known as aminoglycoside antibiotics. It works by stopping the growth of bacteria in the intestines.Neomycin may also be used along with a special diet to treat a certain serious brain problem (hepatic encephalopathy). This condition is caused by too much of a certain natural substance (ammonia). Normally, the liver gets rid of ammonia, but liver disease can cause too much ammonia to build up in the body. This medication helps treat encephalopathy by killing certain intestinal bacteria that make ammonia.This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.

            HOW TO USE: Take this medication by mouth exactly as prescribed by your doctor.To decrease the risk of infection after intestinal surgery, this medication is usually taken for 3 or 4 doses the day before surgery, or as directed by your doctor. Carefully follow your doctor's directions for any diet restrictions and using this medication or other products before surgery.For treating hepatic encephalopathy, this medication is usually taken four times a day for 5 to 6 days, or as directed by your doctor.Dosage is based on your medical condition and response to treatment. To decrease your risk of hearing loss and other side effects, take this medication at the lowest effective dose for the shortest possible time. Do not increase your dose, take it more frequently, or take it for a longer time than prescribed. The manufacturer recommends that this medication should not be taken for longer than 2 weeks during each treatment period.If you are taking this medication for hepatic encephalopathy, take it at evenly spaced times for the best effect. To help you remember, take it at the same times each day. Tell your doctor if your condition lasts or gets worse.

            SIDE EFFECTS: See also Warning section.Nausea, vomiting, and diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: difficulty walking, numbness/tingling, muscle twitching or weakness, seizure.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or 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 Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: Before taking neomycin tablets, tell your doctor or pharmacist if you are allergic to it; or to other aminoglycoside antibiotics (such as tobramycin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: hearing problems (including deafness, decreased hearing), intestinal problems (including blockage, swelling, ulcers), kidney problems, myasthenia gravis, Parkinson's disease.High doses or longer use of neomycin may cause your body to not properly absorb some foods, nutrients (such as iron, Vitamins A and B-12), and drugs (such as digoxin, warfarin). Consult your doctor for more details.Neomycin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using neomycin before having any immunizations/vaccinations.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Newborn and premature babies may be more sensitive to the side effects of this drug, especially hearing problems.This medication is not recommended for use during pregnancy. Although there have been reports of harm in babies born to women using similar drugs, the risk for harm may not be the same with this drug. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. However, many doctors consider breastfeeding safe while using this medication. Consult your doctor before breast-feeding.

            DRUG INTERACTIONS: See also Precautions section.Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your health care professional. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Other medications that may affect the kidneys or hearing may increase the risk of kidney damage or hearing loss if taken with neomycin. Some examples include: amikacin, tobramycin, amphotericin B, cidofovir, cisplatin, polymyxin B, cephalosporins such as cephaloridine, nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, among others.

            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: Do not share this medication with others.Lab and/or medical tests (such as hearing tests, kidney function) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

            MISSED DOSE: If you are taking this drug before a scheduled surgery to prevent infection and you miss a dose, take it as soon as you remember. If it is near the time of the next dose, continue taking your dosing schedule as directed and ask your doctor or pharmacist right away for a new dosing schedule. Do not double the dose to catch up.If you are taking this drug to treat hepatic encephalopathy and you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

            STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.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.

            Information last revised December 2022. Copyright(c) 2022 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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            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
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