No

Antidote

Reverse muscle paralysis with toxic exposure to organophosphate anticholinesterase pesticides and chemicals; control of overdose of drugs used to treat myasthenia gravis (ambenonium, neostigmine, pyridostigmine)

C

Hypersensitivity to pralidoxime or any component; poisonings due to phosphorus, inorganic phosphates, or organic phosphates without anticholinesterase activity

Use with caution in patients with myasthenia gravis; dosage modification required in patients with impaired renal function may not be effective for treating carbamate intoxication; use with caution in patients receiving theophylline, succinylcholine, phenothiazines, respiratory depressants (eg, narcotics, barbiturates). Pramipexole has been associated with somnolence, particularly at higher dosages. Patients have been reported to fall asleep during activities of daily living, including driving, while taking this medicine.

>10%: Local: Pain at injection site after I.M. administration

1% to 10%:

Cardiovascular: Tachycardia, hypertension

Central nervous system: Dizziness, headache, drowsiness

Dermatologic: Rash

Gastrointestinal: Nausea

Neuromuscular & skeletal: Muscle rigidity, weakness

Ocular: Blurred vision, diplopia

Respiratory: Hyperventilation, laryngospasm

Symptoms of overdose include blurred vision, nausea, tachycardia, dizziness

Supportive therapy, mechanical ventilation may be required

Decreased effect: Atropine, although often used concurrently with pralidoxime to offset muscarinic stimulation, these effects can occur earlier than anticipated

Increased effect: Barbiturates (potentiated)

Increased toxicity: Avoid morphine, theophylline, succinylcholine, reserpine and phenothiazines in patients with organophosphate poisoning

Reactivates cholinesterase that had been inactivated by phosphorylation due to exposure to organophosphate pesticides by displacing the enzyme from its receptor sites; removes the phosphoryl group from the active site of the inactivated enzyme

Absorption: Slowly from GI tract

Metabolism: In the liver, not bound to plasma proteins

Half-life: 0.8-2.7 hours

Time to peak serum concentration: I.V.: Within 5-15 minutes

Elimination: 80% to 90% quickly excreted in urine, as metabolites and unchanged drug

Poisoning: I.M. (use in conjunction with atropine; atropine effects should be established before pralidoxime is administered), I.V.:

Adults: 1-2 g; repeat in 1-2 hours if muscle weakness has not been relieved, then at 10- to 12-hour intervals if cholinergic signs recur

Treatment of acetylcholinesterase inhibitor toxicity: Initial: 1-2 g followed by increments of 250 mg every 5 minutes until response is observed

Dosing adjustment in renal impairment: Dose should be reduced

Heart rate, respiratory rate, blood pressure, continuous EKG; cardiac monitor and blood pressure monitor required for I.V. administration

May cause dizziness or drowsiness

Avoid with phenothiazines; effects of barbiturates may be increased

When administered in emergency situation, patient education and instruction should be appropriate to patient condition. Avoid alcohol. Patients should use caution in performing activities which require alertness (driving or operating machinery). Breast-feeding precautions: Breast-feeding is not recommended.

Parenteral: Reconstitute with 20 mL sterile water (preservative free) resulting in 50 mg/mL solution; dilute in normal saline 20 mg/mL and infuse over 15-30 minutes; if a more rapid onset of effect is desired or in a fluid restricted situation, the maximum concentration is 50 mg/mL; the maximum rate of infusion is over 5 minutes

Monitor heart rate, respiratory rate, blood pressure, continuous EKG

Injection: 20 mL vial containing 1 g each pralidoxime chloride with one 20 mL ampul diluent, disposable syringe, needle, and alcohol swab

Injection, as chloride: 300 mg/mL (2 mL)

de Kort WL, Kiestra SH, and Sangster B, "The Use of Atropine and Oximes in Organophosphate Poisoning: A Modified Approach," J Toxicol Clin Toxicol, 1988, 26(3-4):199-208.

Ekins BR and Geller RJ, "Methomyl-Induced Carbamate Poisoning Treated With Pralidoxime Chloride," West J Med, 1994, 161(1):68-70.

Farrar HC, Wells TG, and Kearns GL, "Use of Continuous Infusion of Pralidoxime for Treatment of Organophosphate Poisoning in Children," J Pediatr, 1990, 116(4):658-61.

Jovanovic D, "Pharmacokinetics of Pralidoxime Chloride. A Comparative Study in Healthy Volunteers and in Organophosphorus Poisoning," Arch Toxicol, 1989, 63(5):416-8.

Kurtz PH, "Pralidoxime in the Treatment of Carbamate Intoxication," Am J Emerg Med, 1990, 8(1):68-70.

Medicis JJ, Stork CM, Hoffman RS, et al, "Improved 2-PAM Dosing Regimen in Human Volunteers: A Pharmacokinetic Study," Vet Hum Toxicol, 1994, 36:377.