pralidoxime

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

Myasthenia gravis (may precipitate myasthenic crisis);
Renal impairment (dose ↓ required);
Efficacy in carbamate insecticide poisoning is not known (may ↑ toxicity);
OB: Safety not established in pregnancy; use during pregnancy only if clearly needed;
Lactation: Safety not established in breastfeeding; use while breastfeeding only if clearly needed.

Adv. Reactions/Side Effects ⬆ ⬇

CV: tachycardia

Derm: rash

EENT: blurred vision, diplopia, impaired accommodation

GI: nausea

Local: pain at injection site

MS: muscle rigidity, muscle weakness

Neuro: dizziness, drowsiness, headache

Resp: hyperventilation, LARYNGOSPASM

Interactions ⬆ ⬇

Drug-drug:

Avoid concurrent use with succinylcholine, morphine, aminophylline, theophylline, and respiratory depressants, including barbiturates, opioid analgesics, and sedative/hypnotics, in patients with anticholinesterase poisoning.

Availability ⬆ ⬇

(Generic available)

Powder for injection: 1 g/vial

Route/Dosage ⬆ ⬇

IV route is preferred. In organophosphate poisoning, atropine 2–4 mg IV is given concurrently after hypoxemia is improved. Atropine is repeated every 5–10 min until toxicity is encountered and is then continued for at least 48 hr

Organophosphate Poisoning

IV (Adults ): 1–2 g; may be repeated in 1 hr if muscle paralysis is still present. Additional doses may be given every 10–12 hr if muscle weakness persists. IV route is preferred; if not available, may be given IM or SUBQ.
IM (Adults and Children ≤16 yr and ≥40 kg): Mild symptoms: 600 mg; if mild symptoms persist after 15 min, given another 600 mg; if mild symptoms persist after 15 min, given another 600 mg; if symptoms continue to persist after 1 hr of last 600-mg dose, may repeat dosing regimen of three 600-mg doses given 15 min apart; Severe symptoms: Administer three 600-mg doses in rapid succession (total of 1800 mg); if symptoms continue to persist after 1 hr of last 600-mg dose, may repeat dosing regimen of three 600-mg doses given in rapid succession.
IV (Children ≤16 yr): Give loading dose of 20–50 mg/kg over 15–30 min; after loading dose, may give another dose of 20–50 mg/kg over 15–30 min in 1 hr if muscle paralysis is still present (can repeat dose every 10–12 hr as needed) or initiate continuous infusion of 10–20 mg/kg/hr. IV route is preferred; if not available, may be given IM or SUBQ.
IM (Children ≤16 yr and <40 kg): Mild symptoms: 15 mg/kg; if mild symptoms persist after 15 min, given another 15 mg/kg; if mild symptoms persist after 15 min, given another 15 mg/kg; if symptoms continue to persist after 1 hr of last 15 mg/kg dose, may repeat dosing regimen of three 15 mg/kg doses given 15 min apart; Severe symptoms: Administer three 15 mg/kg doses in rapid succession; if symptoms continue to persist after 1 hr of last 15 mg/kg dose, may repeat dosing regimen of three 15 mg/kg doses given in rapid succession.

Anticholinesterase Overdose

IV (Adults ): 1–2 g, followed by increments of 250 mg every 5 min as needed.

US Brand Names ⬆ ⬇

Action ⬆ ⬇

Reactivates cholinesterase after poisoning with anticholinesterase agents.
May also directly inactivate organophosphates.

Therapeutic effects:

Reversal of muscle paralysis after organophosphate poisoning.

Classifications ⬆ ⬇

Therapeutic Classification: antidotes

Pharmacologic Classification: cholinesterase reactivators

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailability.

Distribution: Widely distributed throughout extracellular water. Does not appear to enter the CNS.

Metabolism/Excretion: 80–90% excreted unchanged by the kidneys.

Half-Life: 0.8–2.7 hr.

ROUTE	ONSET	PEAK	DURATION
IM	unknown	10–20 min	unknown
IV	unknown	5–15 min	unknown

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Indications ⬇

Contraind./Precautions ⬆ ⬇