ComboPen: Full Drug Profile

ComboPen - General Information

ComboPen is an antidote to organophosphate pesticides and chemicals. Organophosphates bind to the esteratic site of acetylcholinesterase, which results initially in reversible inactivation of the enzyme. If given within 24 hours,after organophosphate exposure, pralidoxime reactivates the enzyme cholinesterase by cleaving the phosphate-ester bond formed between the organophosphate and acetylcholinesterase.

Pharmacology of ComboPen

ComboPen is to reactivate cholinesterase (mainly outside of the central nervous system) which has been inactivated by phosphorylation due to an organophosphate pesticide or related compound. The destruction of accumulated acetylcholine can then proceed, and neuromuscular junctions will again function normally. ComboPen also slows the process of "aging" of phosphorylated cholinesterase to a nonreactivatable form, and detoxifies certain organophosphates by direct chemical reaction. The drug has its most critical effect in relieving paralysis of the muscles of respiration. Because pralidoxime is less effective in relieving depression of the respiratory center, atropine is always required concomitantly to block the effect of accumulated acetylcholine at this site. ComboPen relieves muscarinic signs and symptoms, salivation, bronchospasm, etc., but this action is relatively unimportant since atropine is adequate for this purpose.

ComboPen for patients

ComboPen Interactions

When atropine and pralidoxime are used together, the signs of atropinization (flushing, mydriasis, tachycardia, dryness of the mouth and nose) 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 has been delayed. ^{2 - 4}

The following precautions should be kept in mind in the treatment of anticholinesterase poisoning, although they do not bear directly on the use of pralidoxime: since barbiturates are potentiated by the anticholinesterases, they should be used cautiously in the treatment of convulsions; morphine, theophylline, aminophylline, succinylcholine, reserpine, and phenothiazine-type tranquilizers should be avoided in patients with organophosphate poisoning.

ComboPen Contraindications

There are no known absolute contraindications for the use of Protopam. Relative contraindications include known hypersensitivity to the drug and other situations in which the risk of its use clearly outweighs possible benefit.

Additional information about ComboPen

ComboPen Indication: For the treatment of poisoning due to those pesticides and chemicals of the organophosphate class which have anticholinesterase activity and in the control of overdosage by anticholinesterase drugs used in the treatment of myasthenia gravis. Mechanism Of Action: ComboPen is an antidote to organophosphate pesticides and chemicals. Organophosphates bind to the esteratic site of acetylcholinesterase, which results initially in reversible inactivation of the enzyme. If given within 24 hours,after organophosphate exposure, pralidoxime reactivates the enzyme cholinesterase by cleaving the phosphate-ester bond formed between the organophosphate and acetylcholinesterase. Drug Interactions: Not Available Food Interactions: Not Available Generic Name: Pralidoxime Synonyms: Pralidoxime Chloride Drug Category: Antidotes; Cholinesterase Reactivators Drug Type: Small Molecule; Approved Other Brand Names containing Pralidoxime: Protopam; ComboPen; Absorption: Not Available Toxicity (Overdose): Not Available Protein Binding: No binding to plasma proteins Biotransformation: Hepatic Half Life: 74-77 minutes Dosage Forms of ComboPen: Powder, for solution Intramuscular Chemical IUPAC Name: [(E)-(1-methylpyridin-2-ylidene)methyl]-oxoazanium Chemical Formula: C7H9N2O+ Pralidoxime on Wikipedia: https://en.wikipedia.org/wiki/Pralidoxime Organisms Affected: Humans and other mammals