Drug Information for IMITREX (sumatriptan succinate) InjectionFor Subcutaneous Use Only. (GlaxoSmithKline LLC): OVERDOSAGE

Patients (N = 269) have received single injections of 8 to 12 mg without significant adverse effects. Volunteers (N = 47) have received single subcutaneous doses of up to 16 mg without serious adverse events.

No gross overdoses in clinical practice have been reported. Coronary vasospasm was observed after intravenous administration of IMITREX Injection (see CONTRAINDICATIONS). Overdoses would be expected from animal data (dogs at 0.1 g/kg, rats at 2 g/kg) to possibly cause convulsions, tremor, inactivity, erythema of the extremities, reduced respiratory rate, cyanosis, ataxia, mydriasis, injection site reactions (desquamation, hair loss, and scab formation), and paralysis. The half-life of elimination of sumatriptan is about 2 hours (see CLINICAL PHARMACOLOGY: Pharmacokinetics), and therefore monitoring of patients after overdose with IMITREX Injection should continue while symptoms or signs persist, and for at least 10 hours.

It is unknown what effect hemodialysis or peritoneal dialysis has on the serum concentrations of sumatriptan.