Side effects are generally due to an exaggeration of pharmacological effects
of which salivation and fasciculation are the most common. Bowel cramps and
diarrhea may also occur.
The following additional adverse reactions have been reported following the use of either neostigmine bromide or neostigmine methylsulfate:
Allergic: Allergic reactions and anaphylaxis.
Neurologic: Dizziness, convulsions, loss of consciousness, drowsiness,
headache, dysarthria, miosis and visual changes.
Cardiovascular: Cardiac arrhythmias (including bradycardia, tachycardia,
A-V block and nodal rhythm) and nonspecific EKG changes have been reported,
as well as cardiac arrest, syncope and hypotension. These have been predominantly
noted following the use of the injectable form of Prostigmin (neostigmine) .
Respiratory: Increased oral, pharyngeal and brochial secretions,
and dyspnea. Respiratory depression, respiratory arrest and bronchospasm have
been reported following the use of the injectable form of Prostigmin (neostigmine) .
Dermatologic: Rash and urticaria.
Gastrointestinal: Nausea, emesis, flatulence and increased peristalsis.
Genitourinary: Urinary frequency.
Musculoskeletal: Muscle cramps and spasms, arthralgia.
Miscellaneous: Diaphoresis, flushing and weakness.
Certain antibiotics, especially neomycin, streptomycin and kanamycin, have
a mild but definite nondepolarizing blocking action which may accentuate neuromuscular
block. These antibiotics should be used in the myasthenic patient only where
definitely indicated, and then careful adjustment should be made of adjunctive
Local and some general anesthetics, antiarrhythmic agents and other drugs that interfere with neuromuscular transmission should be used cautiously, if at all, in patients with myasthenia gravis; the dose of Prostigmin (neostigmine) may have to be increased accordingly.