No

Antidote; Cholinergic Agonist; Diagnostic Agent, Myasthenia Gravis

Diagnosis of myasthenia gravis; differentiation of cholinergic crises from myasthenia crises; reversal of nondepolarizing neuromuscular blockers; treatment of paroxysmal atrial tachycardia

C

Hypersensitivity to edrophonium or any component, GI or GU obstruction, hypersensitivity to sulfite agents

Use with caution in patients with bronchial asthma and those receiving a cardiac glycoside; atropine sulfate should always be readily available as an antagonist. Overdosage can cause cholinergic crisis which may be fatal. I.V. atropine should be readily available for treatment of cholinergic reactions.

>10%:

Gastrointestinal: Nausea, vomiting, diarrhea, excessive salivation, stomach cramps

Miscellaneous: Diaphoresis (increased)

1% to 10%:

Genitourinary: Polyuria

Ocular: Small pupils, lacrimation

Respiratory: Increased bronchial secretions

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

Symptoms of overdose include muscle weakness, nausea, vomiting, miosis, bronchospasm, respiratory paralysis

Maintain adequate airway; antidote is atropine for muscarinic symptoms; pralidoxime (2-PAM) may also be needed to reverse severe muscle weakness or paralysis; skeletal muscle effects of edrophonium not alleviated by atropine.

Decreased effect: Atropine, nondepolarizing muscle relaxants, procainamide, quinidine

Increased effect: Succinylcholine, digoxin, I.V. acetazolamide, neostigmine, physostigmine

Inhibits destruction of acetylcholine by acetylcholinesterase. This facilitates transmission of impulses across myoneural junction and results in increased cholinergic responses such as miosis, increased tonus of intestinal and skeletal muscles, bronchial and ureteral constriction, bradycardia, and increased salivary and sweat gland secretions.

I.M.:

Onset of effect: Within 2-10 minutes

Duration: 5-30 minutes

I.V.:

Onset of effect: Within 30-60 seconds

Duration: 10 minutes

Distribution: V_d: 1.1 L/kg

Half-life: 1.8 hours

Usually administered I.V., however, if not possible, I.M. or S.C. may be used:

I.M.: 0.5-1 mg

I.V.: Initial: 0.1 mg, followed by 0.4 mg if no response; total dose = 0.5 mg

Children:

Diagnosis: Initial: 0.04 mg/kg over 1 minute followed by 0.16 mg/kg if no response, to a maximum total dose of 5 mg for children <34 kg, or 10 mg for children >34 kg

I.M.:

<34 kg: 1 mg

>34 kg: 5 mg

Titration of oral anticholinesterase therapy: 0.04 mg/kg once given 1 hour after oral intake of the drug being used in treatment; if strength improves, an increase in neostigmine or pyridostigmine dose is indicated

Adults:

Diagnosis:

I.V.: 2 mg test dose administered over 15-30 seconds; 8 mg given 45 seconds later if no response is seen; test dose may be repeated after 30 minutes

I.M.: Initial: 10 mg; if no cholinergic reaction occurs, administer 2 mg 30 minutes later to rule out false-negative reaction

Titration of oral anticholinesterase therapy: 1-2 mg given 1 hour after oral dose of anticholinesterase; if strength improves, an increase in neostigmine or pyridostigmine dose is indicated

Reversal of nondepolarizing neuromuscular blocking agents (neostigmine with atropine usually preferred): I.V.: 10 mg over 30-45 seconds; may repeat every 5-10 minutes up to 40 mg

Termination of paroxysmal atrial tachycardia: I.V. rapid injection: 5-10 mg

Differentiation of cholinergic from myasthenic crisis: I.V.: 1 mg; may repeat after 1 minute. Note: Intubation and controlled ventilation may be required if patient has cholinergic crisis

Dosing adjustment in renal impairment: Dose may need to be reduced in patients with chronic renal failure

Edrophonium is administered by direct I.V. injection; see Usual Dosage

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

May cause drowsiness

None reported

Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to be pregnant. Consult prescriber if breast-feeding.

Parenteral: Edrophonium is administered by direct I.V. injection

Monitor pre- and postinjection strength (cranial musculature is most useful); heart rate, respiratory rate, blood pressure

Injection, as chloride: 10 mg/mL (1 mL, 10 mL, 15 mL)

Fisher DM, et al, "Clinical Pharmacology of Edrophonium in Infants and Children," Anesthesiology, 1984, 61(4):428-33.

Rossen RN, Krikorian J, and Hancock EW, "Ventricular Asystole After Edrophonium Chloride Administration," JAMA, 1976, 235(10):1041-2.

Youngberg JA, "Cardiac Arrest Following Treatment of Paroxysmal Atrial Tachycardia With Edrophonium," Anesthesiology, 1979, 50(3):234-5.