Pyridostigmine Bromide

What it is and how it works

Mechanism of Action Pyridostigmine is a reversible cholinesterase inhibitor.

Indications

Pyridostigmine bromide is indicated for pretreatment against the lethal effects of soman nerve agent poisoning in adults. Pyridostigmine bromide is intended for use in conjunction with protective garments, including a mask. At the first sign of nerve agent poisoning, pyridostigmine bromide should be stopped, and atropine and pralidoxime therapy started immediately. The evidence for the effectiveness of pyridostigmine bromide as pretreatment against soman-induced toxicity was derived from animal studies alone . FOR MILITARY MEDICAL USE ONLY Pyridostigmine bromide is a cholinesterase inhibitor indicated for pretreatment against the lethal effects of soman nerve agent poisoning in adults. Pyridostigmine bromide is for use in conjunction with: Protective garments, including a gas mask, and Immediate atropine and pralidoxime therapy at the first sign of nerve agent poisoning.

Dosage and administration (summary)

The recommended dosage is 30 mg orally every 8 hours, started at least one hour prior to exposure to Soman. At the first sign of soman nerve agent poisoning, discontinue pyridostigmine and administer atropine and 2-PAM. Evaluate use beyond 14 consecutive days in the context of the likelihood of soman exposure. Important Administration Information For Military Medical Use Only. Treatment and Protection for Soman Exposure Pyridostigmine bromide is for use as a pretreatment for exposure to soman nerve agent (see Treatment Timing). Pyridostigmine bromide alone will not protect against exposure to soman.

Contraindications

Pyridostigmine bromide is contraindicated in patients with: Mechanical intestinal or urinary obstruction Known hypersensitivity to pyridostigmine or other anticholinesterase agents Mechanical intestinal or urinary obstruction. Known hypersensitivity to pyridostigmine or other anticholinesterase agents.

Warnings and precautions

At the first sign of soman poisoning, pyridostigmine must be stopped, and atropine and 2-PAM must be administered immediately. Use with caution in persons with increased risk of anticholinergic reactions, such as persons with bronchial asthma, chronic obstructive pulmonary disease, bradycardia, cardiac arrhythmias, beta blocker treatment (increased risk of anticholinergic reactions). Use with caution in persons with bromide sensitivity. In case of serious adverse reactions, advise personnel to temporarily discontinue pyridostigmine and seek immediate medical attention.

Pregnancy

Pregnancy Risk Summary Available data from case reports and case series over decades of use with pyridostigmine bromide have not identified a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes.

Storage and supply

Storage and Handling Store refrigerated between 2°C to 8°C (36°F to 46°F) in carton or foil overwrap to protect from light until the expiration date. Once removed from refrigerator, store at 20°C to 25°C (68°F to 77°F) in carton or foil overwrap for up to 5 years minus half of the time spent under refrigerated storage or until the expiration date, …

Source: Pyridostigmine Bromide (Pyridostigmine Bromide) — US FDA prescribing information, 2025-12-23, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.