pralidoxime (Protopam, 2PAM Antidote, Pralidoxime Auto Injector)
Classes: Cholinergic, Toxicity Antidotes
Dosing and uses of Protopam, 2PAM Antidote (pralidoxime)
Adult dosage forms and strengths
injectable, powder for reconstitution
- 1g/vial
Organophosphate Poisoning
1-2 g IV as 15-30 min infusion, repeat in 1 hr if necessary, Or
Use with atropine, which affects muscarinic receptors; pralidoxime's actions most striking at nicotonic sites (increase muscle strength 10-40 min)
IM: 600 mg IM x3 doses; administer each dose 15 minutes apart for mild symptoms, or in rapid succession for severe symptoms
Renal Impairment: Reduce dose
Acetylcholinesterase Inhibitor Toxicity
Initial: 30 mg/kg IV (IM, SC if no IV access) over 20 min
4-8 mg/kg/hr IV infusion
Other Indications & Uses
Toxicity caused by insecticides and related nerve gases (eg, tabun, sarin, soman)
Pediatric dosage forms and strengths
injectable, powder for reconstitution
- 1g/vial
Organophosphate Poisoning
IV loading dose followed by continuous infusion
- 20-50 mg/kg/dose (not to exceed 2 g/dose) infused IV over 15-30 minutes
- Maintenance: 10-20 mg/kg/hr IV continuous infusion
IV intermittent infusions
- 20-50 mg/kg (not to exceed 2 g/dose) IV infused over 15-30 minutes
- A second dose of 20-50 mg/kg may be indicated after about 1 hr if muscle weakness has not been relieved
- May repeat q10-12hr prn
Other IV administration
- If it is not practical to administer intermittent or continuous IV infusions, or if pulmonary edema is present, the 20-50 mg/kg dose should be given slowly (infused over at least 5 minutes) by IV injection as a 50 mg/mL solution in water
- Additional doses may be given every 10-12 hours if muscle weakness persists
IM administration
- <40 kg: 15 mg/kg/dose IM x3 doses
- 40 kg or greater: Administer as in adults; 600 mg/dose IM x3 doses
- Administer each dose 15 minutes apart for mild symptoms, or in rapid succession for severe symptoms
- Administer in the anterolateral aspect of the thigh to avoid the nerve, artery and vein, as well as the femur
Renal Impairment
Reduce dose
Protopam, 2PAM Antidote (pralidoxime) adverse (side) effects
Frequency not defined
Pain at site
Transient dizziness
Blurred vision
Double vision
Hypertension
Tachycardia
Laryngospasm
Muscle rigidity
Respiratory/cardiac arrest if given too fast IV
Headache
Drowsiness
Nausea
Warnings
Cautions
Administer concomitant atropine
Not equally active against all organophosphates
Give IM if pt is cyanotic
Observe pt for at least 24 hr
Pregnancy and lactation
Pregnancy category: C
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 of Protopam, 2PAM Antidote (pralidoxime)
Onset: 5-15 min
Mechanism of action
Binds to organophosphates and breaks alkyl phosphate-cholinesterase bond to restore activity of acetylcholinesterase
Administration
IV Preparation
Reconstitute by adding 20 mL SWI to the 1 g vial to provide a 50 mg/mL solution (do not use preservative-containing solutions)
Use within a few hours
IV Administration
For infusion, dilute required amount of reconstituted solution to 100 mL with Ns
Infuse over 15-30 min
May also be given as 5 min slow IVp
IM Administration
1 g vial contents may be reconstituted by adding 3 mL SWI or NS to provide a 300 mg/mL solution