Key points
- We recommend to consult your poison centre with the use of this antidote.
- This antidote is only available through the Special Access Program. Accessibility may vary according to the hospitals and the provinces.
- Pralidoxime does not replace the use of atropine in treating muscarinic signs (e.g. bronchorrhea).
- The utility of pralidoxime in the treatment of organophosphate poisoning is controversial.
- Effectiveness is not the same for all organophosphate insecticides.
+ Synonyms and other terms
- 2-PAM
- Pralidoxime chloride
- Protopam®
+ Indications
- Consider in cases of poisoning by organophosphate insecticide causing nicotinic signs (e.g. twitching, muscle weakness) or impairment of the central nervous system (e.g. coma).
+ Dosage
+ Pediatric Dose
The optimal dosage regimen for pralidoxime is unknown.
- Loading dose:
- 25 to 50 mg/kg (maximum 1 g) by slow IV intermittent infusion (see special notes on administration section).
- Maintenance dose:
- Continuous IV infusion of 10 to 20 mg/kg/h (maximum 650 mg/h).
- Duration of treatment depends of symptomatology and the chemical in question.
+ Adult Dose
The optimal dosage regimen for pralidoxime is unknown.
- Loading dose:
- 1 to 2 g by slow IV intermittent infusion (see special notes on administration section)
- Maintenance dose:
- Continuous IV infusion 8 to 10 mg/kg/h (maximum 650 mg/h).
- Duration of treatment depends of symptomatology and the chemical in question.
+ Renal Impairment
- Mainly excreted unchanged in the urine.
- Dose adjustments in severe renal impairment may be required, but specific recommendations are lacking.
+ Hepatic Impairment
No data suggests that the dose should be modified for short-term use.
+ Hemodialysis Patient
Dose may require adjustment, but specific recommendations are lacking.
+ Pregnancy
- Safety has not been demonstrated.
- Nonetheless, pralidoxime must be used without hesitation during pregnancy if the anticipated toxic effects pose a significant risk of morbidity or mortality.
- No data suggests that the dose should be modified for short-term use.
+ Obese or Overweight Patient
No data suggests that the dose should be modified for short-term use.
+ Adverse effects
- Increased creatine kinase.
- Rapid administration may temporarily increase muscarinic effects and cause transitory laryngospasm, muscle rigidity and neuromuscular blockage.
- Hypertension, predominantly of systolic origin, increased heart rate and tachycardia are also reported.
+ Monitoring
- Creatine kinase
- Breathing
- Vital signs
- EKG
+ End of treatment
- Duration of treatment depends on the symptoms and the chemical nature of the intoxicant.
- No recurrence of central or nicotinic effects for 24 hours.
+ Special Notes on Administration
Intravenous Route (IV)
- Slow IV intermittent infusion
- Administer using a volumetric pump.
- Dilute the dose in NS for a final concentration of less than 20 mg/ml.
- Administer over15 to 30 minutes for adults and over 30 minutes for children, at a maximum rate of 200 mg/min.
- In event of pulmonary edema or fluid restriction or when the situation requires rapid administration of antidote:
- Administer the 50 mg/ml concentrated solution by direct IV over at least 5 minutes at a maximum rate of 200 mg/min.
- Continuous IV infusion
- Administer using a volumetric pump.
- Maximum rate of 650 mg/h.
- Suggested preparation method:
- 2000 mg (40 ml) in 210 ml of NS. Final volume = 250 ml. Final concentration = 8 mg/ml.
Subcutaneous Route (SC)
- Possible alternative to IV route.
Intramuscular Route (IM)
- Possible alternative to IV route.
Intraosseous Route (IO)
- Possible alternative to the IV route.
Reconstitution
- For IV administration:
- Dilute the 1000 mg vial with 20 ml of SWFI. Final concentration = 50 mg/ml.
- For IM administration:
- Dilute the 1000 mg vial with 3.3 ml of SWFI. Approximate final concentration = 300 mg/ml.
Compatibility
Partial list only. Consult the pharmacist on duty at your health care facility.
- Compatible solutes: NS.
- Y-site compatibility: no information available.
- Y-site incompatibility: no information available.
Stability
- Unopened vial stable at room temperature between 20°C and 25°C.
- After dilution, discard any unused portion.
+ Available products
- Protopam, 1000 mg/vial, Pd. Inj. 20 ml vials, Baxter Corporation, Special Access Program = yes.
- Format: 6 vials per package
- Telephone: 1 800 387-8399
- Fax: 1 908 281-6625
- e-mail: medinfocanada@baxter.com (link emailing)
+ Amount required to treat a person weighting 70kg during 24 hours
- At least 12g.
+ References
Balali-Mood, Mahdi, and Hamidreza Saber. 2012. “Recent Advances in the Treatment of Organophosphorous Poisonings.” Iranian Journal of Medical Sciences 37 (2):74–91.
Bhalla, Ashish, and Surjit Singh. n.d. “Why Do the Results of Studies on the Effectiveness of Pralidoxime for Treatment of Organophosphate Poisoning Vary?”
Eddleston, Michael, and Fazle Rabbi Chowdhury. 2016. “Pharmacological Treatment of Organophosphorus Insecticide Poisoning: The Old and the (possible) New.” British Journal of Clinical Pharmacology 81 (3):462–70.
Samimi, Azin, Ali Hassan Rahmani, Rojin Ababaf, and Leila Zeidooni. n.d. “An Investigation of Clinical Symptoms and Treatment of Organophosphate Poisoning among Patients Referred to Razi Hospital during 2006 – 2012.”
Vale, J. Allister. 2016. “Oximes.” In Critical Care Toxicology, edited by Jeffrey Brent, Keith Burkhart, Paul Dargan, Benjamin Hatten, Bruno Megarbane, and Robert Palmer, 75:1–16. Cham: Springer International Publishing.
