Dosing & Uses
Dosage Forms & Strengths
IM autoinjector
- atropine (2.1mg/0.7mL) plus pralidoxime chloride (600mg/2mL) in 2 separate chambers; when activated, sequentially administers both drugs IM through a single needle
Organophosphate Poisoning
Indicated for treatment of poisoning by organophosphorus nerve agents as well as organophosphorus insecticides in adults and pediatric patients weighing >41 kg (90 pounds)
2.1 mg atropine/0.7 mL + 600 mg pralidoxime/2 mL IM
Maximum dose: Not to exceed 3 injections unless medical care support available
3 autoinjectors should be available for use in each patient (including healthcare providers) at risk for organophosphorus poisoning; use 1 for mild symptoms plus 2 more for severe symptoms
See also Administration
Mild symptoms
- ≥2 mild symptoms: 1 injection IM; if after 10-15 min there are no severe symptoms experienced, no further injections are necessary
- Additional doses: If, at any time following the first injection, the patient develops any of the severe symptoms, administer 2 additional IM injections in rapid succession
- Mild symptoms: Bradycardia, chest tightness, breathing difficulties, blurred vision, increased salivation (eg, sudden drooling), miosis, nausea or vomiting, runny nose, stomach cramps (acute onset), salivation, teary eyes, wheezing/coughing, tremors/muscular twitching, airway secretions increased
Severe symptoms
- Any severe symptom listed below: 3 injections IM in rapid succession
- Severe symptoms: Confused/strange behavior, involuntary urination/defecation, muscular twitching/generalized weakness (severe), severe breathing difficulties or copious secretion from lung or airway, convulsions, unconsciousness
Dosing Modifications
Renal impairment
- Pralidoxime can cause decreased renal function
- Patients with severe renal impairment may require less frequent doses after initial dose
Hepatic impairment
- Patients with severe hepatic impairment may require less frequent doses after initial dose
Dosing Considerations
Three autoinjectors should be available for use in each patient (including healthcare providers) at risk for organophosphorus poisoning; one (1) for mild symptoms plus two (2) more for severe symptoms; note that individuals may not have all symptoms included under mild or severe symptom category
Only administer drug to patients experiencing symptoms of organophosphorus poisoning in a situation where exposure is known or suspected; autoinjector is intended as an initial treatment of symptoms of organophosphorus nerve agent or insecticide poisonings as soon as symptoms appear; definitive medical care should be sought immediately
The autoinjector should be administered by healthcare providers with adequate training in recognition and treatment of nerve agent or insecticide intoxication
Close supervision of all treated patients is indicated for at least 48 to 72 hours
Dosage Forms & Strengths
IM autoinjector
- atropine (2.1mg/0.7mL) plus pralidoxime chloride (600mg/2mL) in 2 separate chambers; when activated, sequentially administers both drugs IM through a single needle
Organophosphate Poisoning
Indicated for treatment of poisoning by organophosphorus nerve agents as well as organophosphorus insecticides in adults and pediatric patients weighing >41 kg (90 pounds)
≤41 kg: Safety and efficacy not established
>41 kg: 2.1 mg atropine/0.7 mL + 600 mg pralidoxime/2 mL IM
Maximum dose: Not to exceed 3 injections unless medical care support available
3 autoinjectors should be available for use in each patient (including healthcare providers) at risk for organophosphorus poisoning; use 1 for mild symptoms plus 2 more for severe symptoms
Mild symptoms
- ≥2 mild symptoms: 1 injection IM; if after 10-15 min there are no severe symptoms experienced, no further injections are necessary
- Additional doses: If, at any time following the first injection, the patient develops any of the severe symptoms, administer 2 additional IM injections in rapid succession
- Mild symptoms: Bradycardia, chest tightness, breathing difficulties, blurred vision, increased salivation (eg, sudden drooling), miosis, nausea or vomiting, runny nose, stomach cramps (acute onset), salivation, teary eyes, wheezing/coughing, tremors/muscular twitching, airway secretions increased
Severe symptoms
- Any severe symptom listed below: 3 injections IM in rapid succession
- Severe symptoms: Confused/strange behavior, involuntary urination/defecation, muscular twitching/generalized weakness (severe), severe breathing difficulties or copious secretion from lung or airway, convulsions, unconsciousness
Dosing Modifications
Renal impairment
- Pralidoxime can cause decreased renal function
- Patients with severe renal impairment may require less frequent doses after initial dose
Hepatic impairment
- Patients with severe hepatic impairment may require less frequent doses after initial dose
Dosing Considerations
Three autoinjectors should be available for use in each patient (including healthcare providers) at risk for organophosphorus poisoning; one (1) for mild symptoms plus two (2) more for severe symptoms; note that individuals may not have all symptoms included under mild or severe symptom category
Only administer drug to patients experiencing symptoms of organophosphorus poisoning in a situation where exposure is known or suspected; autoinjector is intended as an initial treatment of symptoms of organophosphorus nerve agent or insecticide poisonings as soon as symptoms appear; definitive medical care should be sought immediately
The autoinjector should be administered by healthcare providers with adequate training in recognition and treatment of nerve agent or insecticide intoxication
Close supervision of all treated patients is indicated for at least 48 to 72 hours
Older individuals may be more susceptible to atropine effects
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Adverse Effects
Frequency Not Defined
Injection site reaction (muscle tightness, pain)
Atropine
- Dry mouth
- Blurred vision
- Dry eyes
- Photophobia
- Confusion
- Headache
- Dizziness
Pralidoxime
- Vision changes
- Dizziness, headache
- Drowsiness
- Nausea
- Tachycardia
- Increased blood pressure
- Muscular weakness
- Dry mouth
- Emesis
- Rash
- Dry skin
- Hyperventilation
- Decreased renal function
- Manic behavior
- Transient elevation of LFTs
Warnings
Contraindications
None
Cautions
Caution in patients with known cardiovascular disease or cardiac conduction problems
May inhibit sweating and lead to hyperthermia; avoid excessive exercise and heat exposure
Caution in susceptible individuals at risk for acute glaucoma
Caution in patients with bladder outflow obstruction owing to risk of urinary retention
Caution with partial pyloric stenosis because of risk of complete pyloric obstruction
May cause inspiration of bronchial secretions and formation of dangerous viscid plugs in individuals with chronic lung disease; monitor respiratory status
Individual should not rely solely upon atropine and pralidoxime to provide complete protection from chemical nerve agents and insecticide poisoning (eg, primary protection is the wearing of protective garments)
Elderly individuals may be more susceptible to the effects of atropine
Patients with organophosphorus nerve agent or organophosphorus insecticide poisoning who have received atropine/pralidoxime may exhibit accelerated reversal of the neuromuscular blocking effects of succinylcholine and mivacurium; monitor for neuromuscular effects with concomitant succinylcholine or mivacurium use
Pregnancy & Lactation
Pregnancy
Atropine readily crosses the placental barrier and enters fetal circulation; there are no adequate data on developmental risk associated with use of atropine, pralidoxime, or combination in pregnant women
Lactation
Atropine has been reported to be excreted in human milk; unknown whether pralidoxime is excreted in human milk
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.Pharmacology
Mechanism of Action
Atropine: Competitively blocks the effects of acetylcholine, including excess acetylcholine due to organophosphorus poisoning, at muscarinic cholinergic receptors on smooth muscle, cardiac muscle, secretory gland cells, and in peripheral autonomic ganglia and the central nervous system
Pralidoxime: Reactivates acetylcholinesterase which has been inactivated by phosphorylation due to an organophosphorous nerve agent or insecticide; reactivated acetylcholinesterase hydrolyzes excess acetylcholine, which is clinically important because only a small proportion of active acetylcholinesterase is needed to maintain vital functions
Absorption
Atropine
- Rapidly and well absorbed after IM administration
- Peak plasma concentration: 13 ng/mL
- Peak plasma time: 31 minutes
Pralidoxime
- Rapidly absorbed after IM injection
- Peak plasma concentration: 7 mcg/mL
- Peak plasma time: 28 minutes
Distribution
Atropine
- Rapidly and widely throughout the body
- Crosses blood brain barrier and enteres fetal circulation
- Protein bound: 14-22%
Pralidoxime
- Distributed throughout the extracellular wate
- No protein binding
- Vd: 0.6-2.7 L/kg (may increase in severe organophosphate intoxication)
Metabolism
Atropine: Liver via enzymatic hydrolysis
Pralidoxime: Hepatic
Elimination
Atropine
- Half-life: 2.4 hr
- Excretion: 50-60% unchanged in urine
Pralidoxime
- Half-life: 2 hr
- Excretion: 72-94% in urine (partly unchanged and partly as a metabolite)
Administration
IM Administration
ATNAA: Administer IM in the lateral thigh muscle or buttocks; see prescribing information for complete detailed administration instructions
DuoDote: Administer IM into the mid-lateral thigh; see prescribing information for complete detailed administration instructions
Storage
Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F)
Keep from freezing
Protect from light
Images
Formulary
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