No

Acetylcholinesterase Inhibitor

Symptomatic treatment of myasthenia gravis; also used as an antidote for nondepolarizing neuromuscular blockers; not a cure; patient may develop resistance to the drug

C

Hypersensitivity to pyridostigmine, bromides, or any component; GI or GU obstruction

Use with caution in patients with epilepsy, asthma, bradycardia, hyperthyroidism, cardiac arrhythmias, or peptic ulcer; adequate facilities should be available for cardiopulmonary resuscitation when testing and adjusting dose for myasthenia gravis; have atropine and epinephrine ready to treat hypersensitivity reactions; overdosage may result in cholinergic crisis, this must be distinguished from myasthenic crisis; anticholinesterase insensitivity can develop for brief or prolonged periods

>10%:

Gastrointestinal: Diarrhea, nausea, stomach cramps, mouth watering

Miscellaneous: Diaphoresis (increased)

1% to 10%:

Genitourinary: Urge to urinate

Ocular: Small pupils, lacrimation

Respiratory: Increased bronchial secretions

<1%: Bradycardia, A-V block, seizures, headache, dysphoria, drowsiness, thrombophlebitis, muscle spasms, weakness, miosis, diplopia, laryngospasm, respiratory paralysis, hypersensitivity, hyper-reactive cholinergic responses

Symptoms of overdose include muscle weakness, blurred vision, excessive sweating, tearing and salivation, nausea, vomiting, diarrhea, hypertension, bradycardia, paralysis

Atropine is the treatment of choice for intoxications manifesting with significant muscarinic symptoms. Atropine I.V. 2-4 mg every 3-60 minutes (or 0.04-0.08 mg I.V. every 5-60 minutes if needed for children) should be repeated to control symptoms and then continued as needed for 1-2 days following the acute ingestion.

Increased effect of depolarizing neuromuscular blockers (succinylcholine)

Increased toxicity with edrophonium

Protect from light

Inhibits destruction of acetylcholine by acetylcholinesterase which facilitates transmission of impulses across myoneural junction

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

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

Absorption: Oral: Very poor (10% to 20%) from GI tract

Metabolism: In the liver

Normally, sustained release dosage form is used at bedtime for patients who complain of morning weakness

Oral:

Children: 7 mg/kg/day in 5-6 divided doses

Adults: Initial: 60 mg 3 times/day with maintenance dose ranging from 60 mg to 1.5 g/day; sustained release formulation should be dosed at least every 6 hours (usually 12-24 hours)

I.M., I.V.:

Children: 0.05-0.15 mg/kg/dose (maximum single dose: 10 mg)

Adults: 2 mg every 2-3 hours or 1/30th of oral dose

Reversal of nondepolarizing neuromuscular blocker: I.M., I.V.:

Children: 0.1-0.25 mg/kg/dose preceded by atropine

Adults: 10-20 mg preceded by atropine

aminotransferase [ALT (SGPT)/AST (SGOT)] (S), amylase (S)

May rarely cause dysphoria or drowsiness

None reported; but mouth watering is common and may be additive to the sialorrhea associated with clozapine therapy

This drug will not cure myasthenia gravis, but may help reduce symptoms. Use as directed; do not increase dose or discontinue without consulting prescriber. Take extended release tablets at bedtime; do not chew or crush extended release tablets. Maintain adequate hydration (2-3 L/day of fluids unless instructed to restrict fluid intake). May cause dizziness, drowsiness, or hypotension (rise slowly from sitting or lying position and use caution when driving or climbing stairs); vomiting or loss of appetite (frequent small meals, frequent mouth care, chewing gum, or sucking lozenges may help); or diarrhea (boiled milk, yogurt, or buttermilk may help). Report persistent abdominal discomfort; significantly increased salivation, sweating, tearing, or urination; flushed skin; chest pain or palpitations; acute headache; unresolved diarrhea; excessive fatigue, insomnia, dizziness, or depression; increased muscle, joint, or body pain; vision changes or blurred vision; or shortness of breath or wheezing. Pregnancy precautions: Inform prescriber if you are or intend to be pregnant.

Do not crush sustained release drug product; observe for cholinergic reactions, particularly when administered I.V.

Injection, as bromide: 5 mg/mL (2 mL, 5 mL)

Syrup, as bromide (raspberry flavor): 60 mg/5 mL (480 mL)

Tablet, as bromide: 60 mg

Tablet, as bromide, sustained release: 180 mg

Dunn MA and Sidell FR, "Progress in Medical Defense Against Nerve Agents," JAMA, 1989, 262(5):649-52.

Keeler JR, Hurst CG, and Dunn MA, "Pyridostigmine Used as a Nerve Agent Pretreatment Under Wartime Conditions," JAMA, 1991, 266(5):693-5.

Sidell FR and Borak J, "Chemical Warfare Agents: II. Nerve Agents," Ann Emerg Med, 1992, 21(7):865-71.