pralidoxime (Protopam, 2PAM Antidote, Pralidoxime Auto Injector)

Dosing and uses of Protopam, 2PAM Antidote (pralidoxime)

• Adult
• Pediatric

 

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