EFFICACY AND ADVERSE EVENTS OF SUBCUTANEOUS, ORAL, AND INTRANASAL SUMATRIPTAN USED FOR MIGRAINE TREATMENT - A SYSTEMATIC REVIEW BASED ON NUMBER NEEDED TO TREAT

Objectives: To evaluate the efficacy, speed of onset, and adverse even ts of 6 mg subcutaneous, 100 mg oral, and 20 mg intranasal sumatriptan in the treatment of migraine attacks. Design: Systematic review of pl acebo-controlled randomized clinical trials. Data sources: Thirty tria ls up to April 1997 retrieved from a systematic literature search (Med line, review papers, handsearching of journals, congress proceedings, manufacturer's database); no restriction on language. Outcome paramete rs: Numbers needed to heat (NNT) were calculated for relief of headach e and for adverse events (when data were available). Therapeutic gain was used to evaluate speed of onset of action. Results: Subcutaneous s umatriptan was more efficacious, combined number needed to treat 2.0 a t 1 h, than oral (3.0 at 2 h) and intranasal sumatriptan (3.1 at 2 h). For adverse events, the NNT was 3.0 for subcutaneous and 8.3 for oral sumatriptan. Only limited data on adverse events for intranasal sumat riptan were available. Therapeutic gain analysis during the first 2 h showed that subcutaneous sumatriptan was the fastest-acting form of ad ministration. Conclusions: Subcutaneous sumatriptan in a dose of 6 mg is significantly more efficacious than 100 mg of oral sumatriptan, but causes more adverse events than oral sumatriptan. Subcutaneous sumatr iptan is the form with the quickest onset of action. Intranasal sumatr iptan has the same efficacy as oral sumatriptan and a quicker onset of action than the oral form, but with a limited therapeutic effect for the first 30 min after administration.