Pronunciation:

(peer id oh STIG meen)

U.S. Brand Names:

Synonyms:

Generic Available:

Canadian Brand Names:

Use:

Military use: Pretreatment for Soman nerve gas exposure

Pregnancy Risk Factor:

Pregnancy Implications:

Lactation:

Contraindications:

Warnings/Precautions:

Regonol® injection contains 1% benzyl alcohol as the preservative (not intended for use in newborns).

Adverse Reactions:

Cardiovascular: Arrhythmias (especially bradycardia), hypotension, decreased carbon monoxide, tachycardia, AV block, nodal rhythm, nonspecific ECG changes, cardiac arrest, syncope, flushing

Central nervous system: Convulsions, dysarthria, dysphonia, dizziness, loss of consciousness, drowsiness, headache

Dermatologic: Skin rash, thrombophlebitis (I.V.), urticaria

Gastrointestinal: Hyperperistalsis, nausea, vomiting, salivation, diarrhea, stomach cramps, dysphagia, flatulence, abdominal pain

Genitourinary: Urinary urgency

Neuromuscular & skeletal: Weakness, fasciculations, muscle cramps, spasms, arthralgia, myalgia

Ocular: Small pupils, lacrimation, amblyopia

Respiratory: Increased bronchial secretions, laryngospasm, bronchiolar constriction, respiratory muscle paralysis, dyspnea, respiratory depression, respiratory arrest, bronchospasm

Miscellaneous: Diaphoresis (increased), anaphylaxis, allergic reactions

Overdosage/Toxicology:

Drug Interactions:

Aminoglycosides (gentamicin, kanamycin, neomycin, streptomycin): Use of high parenteral doses may intensify/prolong neuromuscular blockade, or lead to resistance of neuromuscular blockade reversal, especially if used with other nondepolarizing neuromuscular-blocking drugs.

Antibiotics (bacitracin, colistin, polymyxin B, sodium colistimethate, tetracycline): Use of high parenteral doses may intensify/prolong neuromuscular blockade, or lead to resistance of neuromuscular blockade reversal, especially if used with other nondepolarizing neuromuscular-blocking drugs.

Beta blockers: Pyridostigmine and beta-blockers may both cause bradycardia and hypotension, effect may be additive; monitor.

Depolarizing neuromuscular-blocking agents (succinylcholine): Increased neuromuscular blocking effect with concomitant use.

Edrophonium: Increased toxicity with concomitant use.

Magnesium: Patients with elevated serum magnesium concentrations may experience enhanced neuromuscular blockage with blocking agents. The reversing effect of pyridostigmine may be compensated.

Quinidine: Recurrent paralysis may occur when quinidine is administered with nondepolarizing neuromuscular-blocking drugs. This may complicate attempts to reverse blockade with pyridostigmine.

Quinolone antibiotics (ciprofloxacin, norfloxacin): Case reports suggest these drugs may exhibit neuromuscular-blocking effects (especially in some patients with myasthenia gravis); monitor.

Stability:

Injection: Protect from light.

Tablet:

30 mg: Store under refrigeration at 2°C to 8°C (36°F to 46°F) and protect from light; stable at room temperature for up to 3 months

Mestinon®: Store at 25°C (77°F); protect from moisture

Compatibility:

Y-site administration: Compatible: Heparin, hydrocortisone sodium succinate, potassium chloride, vitamin B complex with C

Compatibility in syringe: Compatible: Glycopyrrolate

Mechanism of Action:

Pharmacodynamics/Kinetics:

Onset of action: Oral, I.M.: 15-30 minutes; I.V. injection: 2-5 minutes

Duration: Oral: Up to 6-8 hours (due to slow absorption); I.V.: 2-3 hours

Absorption: Oral: Very poor

Distribution: 19 ± 12 L

Metabolism: Hepatic

Bioavailability: 10% to 20%

Half-life elimination: 1-2 hours; Renal failure: 6 hours

Excretion: Urine (80% to 90% as unchanged drug)

Dosage:

Myasthenia gravis:

Oral:

Children: 7 mg/kg/24 hours divided into 5-6 doses

Adults: Highly individualized dosing ranges: 60-1500 mg/day, usually 600 mg/day divided into 5-6 doses, spaced to provide maximum relief

Sustained release formulation: Highly individualized dosing ranges: 180-540 mg once or twice daily (doses separated by at least 6 hours); Note: Most clinicians reserve sustained release dosage form for bedtime dose only.

I.M., slow I.V. push:

Children: 0.05-0.15 mg/kg/dose

Adults: To supplement oral dosage pre- and postoperatively during labor and postpartum, during myasthenic crisis, or when oral therapy is impractical: ~1/30th of oral dose; observe patient closely for cholinergic reactions

or

I.V. infusion: Initial: 2 mg/hour with gradual titration in increments of 0.5-1 mg/hour, up to a maximum rate of 4 mg/hour

Pretreatment for Soman nerve gas exposure (military use): Oral: Adults: 30 mg every 8 hours beginning several hours prior to exposure; discontinue at first sign of nerve agent exposure, then begin atropine and pralidoxime

Reversal of nondepolarizing muscle relaxants: Note: Atropine sulfate (0.6-1.2 mg) I.V. immediately prior to pyridostigmine to minimize side effects: I.V.:

Children: Dosing range: 0.1-0.25 mg/kg/dose*

Adults: 0.1-0.25 mg/kg/dose; 10-20 mg is usually sufficient*

*Full recovery usually occurs 15 minutes, but 30 minutes may be required

Dosage adjustment in renal dysfunction: Lower dosages may be required due to prolonged elimination; no specific recommendations have been published

Administration:

Monitoring Parameters:

Test Interactions:

Patient Education:

Anesthesia and Critical Care Concerns/Other Considerations:

Dental Health: Effects on Dental Treatment:

Dental Health: Vasoconstrictor/Local Anesthetic Precautions:

Mental Health: Effects on Mental Status:

Mental Health: Effects on Psychiatric Treatment:

Dosage Forms:

Injection, solution, as bromide:

Mestinon®: 5 mg/mL (2 mL)

Regonol®: 5 mg/mL (2 mL) [contains benzyl alcohol]

Syrup, as bromide (Mestinon®): 60 mg/5 mL (480 mL) [raspberry flavor; contains alcohol 5%, sodium benzoate]

Tablet, as bromide (Mestinon®): 60 mg

Tablet, sustained release, as bromide (Mestinon® Timespan®): 180 mg

International Brand Names: