pyridostigmine bromide /pir′idōstig″mēn/ , an acetylcholinesterase inhibitor that prolongs the effects of neuronally released acetylcholine. INDICATIONS: It is prescribed in the treatment of myasthenia gravis and is used as an antagonist to nondepolarizing muscle relaxants, such as curare. CONTRAINDICATIONS: Intestinal or urinary obstruction, bradycardia, hypotension, or known hypersensitivity to this drug or to other anticholinesterases prohibits its use. ADVERSE EFFECTS: Among the more serious adverse effects are nausea, diarrhea, abdominal cramps, muscle cramps, and weakness.