Pralidoxime

Mechanism-of-action class: Cholinesterase Reactivators.

• PROTOPAM Chloride is indicated as an antidote: (1) in the treatment of poisoning due to those pesticides and chemicals (e.g., nerve agents) of the organophosphate class which have anticholinesterase activity and (2) in the control of overdosage by anticholinesterase drugs used in the treatment of myasthenia gravis. The principal indications for the use of PROTOPAM Chloride are muscle weakness and respiratory depression.

• There are no known absolute contraindications for the use of PROTOPAM Chloride (see PRECAUTIONS, Drug Interactions and DOSAGE AND ADMINISTRATION ). Relative contraindications include known hypersensitivity to the drug and other situations in which the risk of its use clearly outweighs possible benefit.contraindicated

Organophosphate Poisoning Treatment should include general supportive care, atropinization, and decontamination, in addition to the use of PROTOPAM Chloride. Treatment is most effective if initiated immediately after poisoning. Administration of PROTOPAM Chloride should be carried out slowly and, preferably, by infusion. If intravenous administration is not feasible, intramuscular or subcutaneous injection should be used. Generally, little is accomplished if PROTOPAM Chloride is given more than 36 hours after termination of exposure to the poison. When the poison has been ingested, it is particularly important to take into account the likelihood of continuing absorption from the lower bowel since this constitutes new exposure and fatal relapses have been reported after initial improvement. In such cases, additional doses of PROTOPAM Chloride may be needed every three to eight hours. In effect, the patient should be “titrated” with PROTOPAM Chloride as long as signs of poisoning recur. As in all cases of organophosphate poisoning, care should be taken to keep the patient under observation for at least 48 to 72 hours. If dermal exposure has occurred, clothing should be removed and the hair and skin washed thoroughly with sodium bicarbonate or alcohol as soon as possible. Supportive care, including airway management, respiratory and cardiovascular support, correction of metabolic abnormalities, and seizure control, may be necessary in cases of severe organophosphate poisoning. Atropine should be given as soon as possible after hypoxemia is improved.

PROTOPAM Chloride is not effective in the treatment of poisoning due to phosphorus, inorganic phosphates, or organophosphates not having anticholinesterase activity. PROTOPAM Chloride is not indicated as an antidote for intoxication by pesticides of the carbamate class since it may increase the toxicity of carbaryl.

Forty to 60 minutes after intramuscular injection, mild to moderate pain may be experienced at the site of injection. Pralidoxime chloride may cause blurred vision, diplopia and impaired accommodation, dizziness, headache, drowsiness, nausea, tachycardia, increased systolic and diastolic blood pressure, hyperventilation, and muscular weakness when given parenterally to normal volunteers who have not been exposed to anticholinesterase poisons. In patients, it is very difficult to differentiate the toxic effects produced by atropine or the organophosphate compounds from those of the drug. Elevations in SGOT and/or SGPT enzyme levels were observed in 1 of 6 normal volunteers given 1200 mg of pralidoxime chloride intramuscularly, and in 4 of 6 volunteers given 1800 mg intramuscularly. Levels returned to normal in about 2 weeks. Transient elevations in creatine phosphokinase were observed in all normal volunteers given the drug. When atropine and pralidoxime chloride are used together, the signs of atropinization may occur earlier than might be expected when atropine is used alone. This is especially true if the total dose of atropine has been large and the administration of pralidoxime chloride has been delayed. Excitement and manic behavior immediately following recovery of consciousness have been reported in several cases. However, similar behavior has occurred in cases of organophosphate poisoning that were not treated with pralidoxime chloride.

Pregnancy Teratogenic Effects: Animal reproduction studies have not been conducted with pralidoxime chloride. It is also not known whether pralidoxime chloride can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Pralidoxime chloride should be given to a pregnant woman only if clearly needed.

Metabolism

Animal studies suggest that the minimum therapeutic concentration of pralidoxime in plasma is 4 µg/mL; this level is reached in about 16 minutes after a single injection of 600 mg pralidoxime chloride. In one study of healthy adult volunteers and patients self-poisoned with organophosphate compounds, a single intramuscular injection of 1000 mg of pralidoxime chloride resulted in mean peak plasma levels of 7.5 ± 1.7 µg/mL and 9.9 ± 2.4 µg/mL, respectively.

Manifestations of Overdosage Observed in normal subjects only: dizziness, blurred vision, diplopia, headache, impaired accommodation, nausea, slight tachycardia. In therapy, it has been difficult to differentiate side effects due to the drug from those due to the effects of the poison.

• Mar 11, 1964NDANDA014134Baxter Hlthcare Corp
• Jan 17, 2002NDANDA021175Us Army
• Sep 28, 2006NDANDA021983Mmt

1. 1Accidental Exposure623%
2. 2Expired Drug Administered519%
3. 3Injection Site Injury415%
4. 4Drug Ineffective312%
5. 5Accidental Exposure To Product27.7%
6. 6Expired Product Administered27.7%
7. 7Extrapyramidal Disorder27.7%
8. 8Injection Site Pain27.7%
9. 9Mental Disorder Due To A General Medical Condition27.7%
10. 10Peripheral Swelling27.7%
11. 11Agitation13.8%
12. 12Agranulocytosis13.8%
13. 13Apnoea13.8%
14. 14Asthma13.8%
15. 15Basal Ganglia Haemorrhage13.8%

The 5 most recently updated of 5 ClinicalTrials.gov registrations naming Pralidoxime as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Outcome of Moderate Severity in OPC Poisoning Patients When Treated With Pralidoxime
  Completed · Phase 2 · Interventional · 96 enrolled · Sir Salimullah Medical College Mitford Hospital
  NCT06111352updated 2024-10-09
• Serum Cholinesterase Level in Aluminum Phosphide Poisoning, the Possible Proposing Role of Atropin & Pralidoxime
  Unknown · Observational · 50 enrolled · Assiut University
  NCT04192526updated 2020-05-13
• Adding Nebulized Salbutamol to Intravenous Atropine and Oxygen in OP Poisoning
  Completed · Phase 3 · Interventional · 75 enrolled · Sylhet M.A.G.Osmani Medical College
  NCT02160548updated 2015-12-29
• Is the WHO Recommended Dose of Pralidoxime Effective in the Treatment of Organophosphorus Poisoning?
  Completed · Phase 1 · Interventional · 100 enrolled · Sheri Kashmir Institute of Medical Sciences
  NCT02040350updated 2014-01-20
• Study to Know the Efficacy of Higher Doses of Pralidoxime in Patients of Organophpsphorus Poisoning.
  Completed · Interventional · 200 enrolled · Giriraj Hospital
  NCT00333944updated 2006-06-06

Frequently asked questions

How does Pralidoxime work?

Mechanism-of-action class: Cholinesterase Reactivators.

What is Pralidoxime used for?

According to FDA labeling, Pralidoxime carries indications including: PROTOPAM Chloride is indicated as an antidote: (1) in the treatment of poisoning due to those pesticides and chemicals (e.g., nerve agents) of the organophosphate class which have anticholinesterase activity and (2) in the control of overdosage by anticholinesterase drugs used in the treatment of myasthenia gravis. The principal indications for the use of PROTOPAM Chloride are muscle weakness and respiratory depression.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Pralidoxime?

Pralidoxime is classified as Antidotes, Cholinesterase Reactivator, Cholinesterase Reactivators, Decreased Acetylcholine Activity.

What are the brand names for Pralidoxime?

Pralidoxime is marketed under brand names including Duodote, Protopam.

What are the contraindications for Pralidoxime?

Pralidoxime labeling lists contraindications including: There are no known absolute contraindications for the use of PROTOPAM Chloride (see PRECAUTIONS, Drug Interactions and DOSAGE AND ADMINISTRATION ). Relative contraindications include known hypersensitivity to the drug and other situations in which the risk of its use clearly outweighs possible benefit.. Always consult the full prescribing information and a clinician.