Edrophonium ChlorideRx

Trade Names: Tensilon, Enlon

Drug Class: Short-acting acetylcholinesterase inhibitor

Preparations: Injection, 10 mg/mL

Dose: Diagnostic test for myasthenia gravis: 2 mg i.v. over 15–30 seconds; then, if no response is seen, 8 mg 45 seconds later

Indications: Diagnostic test for myasthenia gravis; used to differentiate cholinergic crisis from myasthenic crisis

Mechanism of Action: Increases acetylcholine concentrations by inhibiting its breakdown by acetylcholinesterase

Contraindications: Hypersensitivity to edrophonium or sulfites; GI or genitourinary obstruction

Precautions: May worsen weakness if this is caused by overtreatment (cholinergic crisis); intravenous atropine must be available to treat cholinergic symptoms. Use with caution in patients with asthma or those receiving cardiac glycosides.

Monitoring: Must be administered under medical supervision with resuscitation facilities on hand.

Pregnancy Risk: C

Adverse Effects
Common: Cholinergic symptoms: nausea, vomiting, cramps, diarrhea, salivation, sweating, small pupils, lacrimation
Less common: Bradycardia, seizures, hypersensitivity, bronchospasm, laryngospasm

Drug Interactions: Anticholinesterases, neostigmine and physostigmine: Increased effect.

Clinical Pharmacology: Onset of action is within 60 seconds; duration of effect is 10 minutes.

Cost: $$$