Also found in: Encyclopedia.

pyridostigmine bromide

Mestinon, Mestinon-SR (CA), Mestinon Timespan, Regonol

Pharmacologic class: Anticholinesterase

Therapeutic class: Muscle stimulant, antimyasthenic

Pregnancy risk category C


Prevents acetylcholine destruction, resulting in stronger contractions of muscles weakened by myasthenia gravis or curare-like neuromuscular blockers


Injection: 5 mg/ml

Syrup: 60 mg/5 ml

Tablets: 60 mg

Tablets (extended-release): 180 mg

Indications and dosages

Myasthenia gravis

Adults: 600 mg P.O. given over 24 hours, with doses spaced for maximum symptom relief. For myasthenic crisis, 2 mg or 1/30 of oral dose I.M. or very slow I.V. q 2 to 3 hours.

Postoperative reversal of nondepolarizing neuromuscular blockers

Adults: 10 to 20 mg slow I.V. injection (range is 0.1 to 0.25 mg/kg) with or immediately after 0.6 to 1.2 mg atropine sulfate I.V.

Dosage adjustment

• Renal impairment
• Seizure disorders

Off-label uses

• Myasthenia gravis in children
• Constipation in patients with Parkinson's disease
• Nerve agent prophylaxis


• Hypersensitivity to drug or bromides
• Mechanical intestinal or urinary tract obstruction


Use cautiously in:
• seizure disorders, bronchial asthma, coronary occlusion, arrhythmias, bradycardia, hyperthyroidism, peptic ulcer, vagotonia, cholinergic crisis
• pregnant or breastfeeding patients
• children (safety and efficacy not established).


Don't exceed I.V. injection rate of 1 mg/minute.

Don't give concurrently with other anticholinesterase drugs.
• Have atropine available for use in emergencies.

Adverse reactions

CNS: headache, dysarthria, dysphoria, drowsiness, dizziness, headache, syncope, loss of consciousness, seizures

CV: decreased cardiac output leading to hypotension, bradycardia, nodal rhythm, atrioventricular block, cardiac arrest, arrhythmias

EENT: diplopia, lacrimation, miosis, spasm of accommodation, conjunctival hyperemia

GI: nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, flatulence dysphagia, increased salivation

GU: urinary frequency, urgency, or incontinence

Musculoskeletal: muscle weakness, fasciculations, and cramps; joint pain

Respiratory: increased pharyngeal and tracheobronchial secretions, dyspnea, central respiratory paralysis, respiratory muscle paralysis, laryngospasm, bronchospasm, bronchiolar constriction

Skin: diaphoresis, flushing, rash, urticaria

Other: thrombophlebitis at I.V. site, cholinergic crisis, anaphylaxis


Drug-drug.Aminoglycosides: potentiation of neuromuscular blockade

Anesthetics (general and local), antiarrhythmics: decreased anticholinesterase effects

Atropine, belladonna derivatives: suppression of parasympathomimetic GI symptoms (leaving only fasciculations and voluntary muscle paralysis as signs of anticholinesterase overdose)

Corticosteroids: decreased anticholinesterase effects; after corticosteroid withdrawal, increased anticholinesterase effects

Ganglionic blockers (such as mecamy-lamine): increased anticholinesterase effects

Magnesium: antagonism of beneficial anticholinesterase effects

Nondepolarizing neuromuscular blockers (atropine, pancuronium, tubocurarine): antagonism of neuromuscular blockade and reversal of muscle relaxation after surgery (with parenteral pyridostigmine)

Other anticholinesterase drugs: in patients with myasthenia gravis, symptoms of anticholinesterase overdose that mimic underdose, causing patient's condition to worsen

Succinylcholine: increased and prolonged neuromuscular blockade (including respiratory depression)

Patient monitoring

• Assess patient's response to each dose.
• Monitor vital signs, ECG, and cardiovascular and respiratory status.

Assess for signs and symptoms of overdose, which indicate cholinergic crisis.

Patient teaching

• If patient is using syrup, advise him to pour it over ice.
• Instruct patient using extended-release tablets not to crush them.

Teach patient to recognize and promptly report signs and symptoms of overdose, including muscle fasciculations, sweating, excessive salivation, and constricted pupils.
• Tell patient drug may cause headache and muscle cramps. Encourage him to discuss activity recommendations and pain management with prescriber.
• Advise patient to monitor and report his response to ongoing therapy so that optimal dosage can be determined.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.


a trademark for a neuromuscular blocking agent (pyridostigmine bromide).


An oral agent used to manage myasthenia gravis.

Adverse effects
• Muscarinic—Nausea, vomiting, diarrhoea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis, diaphoresis; reversed with atropine.
• Nicotinic—Muscle cramps, fasciculation and weakness.


Pyridostigmine, see there.

Pyridostigmine bromide (Mestinon)

An anticholinesterase drug used in treating myasthenia gravis.
Mentioned in: Myasthenia Gravis
References in periodicals archive ?
Food and Drug Administration (FDA) has approved generic Mestinon Timespan Tablets (pyridostigmine bromide extended release), 180 mg.
Our study shows you individual revenue forecasts to 2024 for four marketed drugs: -- Xenazine (tetrabenazine) -- Rilutek (riluzole) -- Mestinon (pyridostigmine) -- Imuran (azathioprine).
Since the beginning, she had been taking Mestinon every five hours or so and therefore was able to work at a local nursing facility doing patient care.
The ongoing Phase IIa clinical study is currently evaluating the safety and efficacy of three different, once-daily oral doses of EN101 in patients with MG compared with Mestinon.
Myasthenia Autoimmune Muscle weakness Anticholinesterase gravis (12) attack against and fatigue, agents such as the cells at the including Mestinon junction of weakness of the (pyridostigmine), nerves and eye muscles.
Drug therapy consisted of Prednisone (60 mg daily) and Mestinon (60 mg 4 x daily) (anticholinesterase).
Mestinon (pyridostigmine bromide), Prostigmin (neostigmine), or Mytelase (ambenonium chloride) is commonly given.
If dry mouth or constipation does develop, try adding the cholinesterase inhibitor Mestinon (pyridostigmine bromide), which does not interfere with amitriptyline's action, he added.
You can expect to regain muscle strength by taking Mestinon, a drug which boosts the action of acetylcholine.
10] Pyridostigmine is a well-established drug marketed as Mestinon [R] primarily for the treatment of the unusual disease, myasthenia gravis.
Meda's sales of Mestinon (treatment of myasthenia gravis, an autoimmune disease) amounted to SEK 129 million (137).
1 Mestinon (Pyridostigmine bromide; Valeant Pharmaceuticals) 5.