Thirty RCTs were included in the review. Twelve trials compared 6 mg subcutaneous sumatriptan with placebo (1,927 participants with sumatriptan and 1,200 participants with placebo); twelve trials compared 100 mg oral sumatriptan with placebo (1,854 participants with sumatriptan and 1,036 participants with placebo); and six trials compared 20 mg nasal sumatriptan with placebo (917 participants with sumatriptan and 503 participants with placebo).
Subcutaneous sumatriptan had a higher therapeutic gain than intranasal and oral sumatriptan early after administration. Intranasal sumatriptan had a small therapeutic gain of 8% at 15 minutes, whereas for oral sumatriptan a similar small therapeutic gain of 10% was found after 30 minutes.
The combined therapeutic gain was 51% (95% CI: 48%, 53%) for subcutaneous sumatriptan at 1 hour, 33& (95% CI: 29.5%, 36%) for oral sumatriptan, whereas for intranasal sumatriptan it was 32% (95% CI: 27%, 38%). The combined therapeutic gains show that 6 mg sumatriptan at 1 hour is superior to either 100 mg oral or 20 mg intranasal sumatriptan at 2 hours.
The NNT for individual trials for a success for 6 mg subcutaneous sumatriptan at 1 hour varied from 1.3 to 2.6, and when the results from all 12 randomised trials were combined the NNT for a success was 2.0 (95% CI: 1.9, 2.1). The NNT for adverse events was 3.0 (95% CI: 2.7, 3.4).
The NNT for a success for 100 mg oral sumatriptan at 2 hours varied from 2.5 to 4.8, and when the results from all 12 randomised trials were combined the NNT for success was 3.0 (95% CI: 2.8, 3.4). The NNT for adverse events was 8.3 (95% CI: 6.3, 12.2).
The NNT for a success for 20 mg intranasal sumatriptan at 2 hours varied from 2.3 to 3.6, and when the results from all 6 randomised trials were combined the NNT for a success was 3.1 (95% CI: 2.7, 3.8). The NNT for adverse events was not reported.