Twenty-four RCTs were included (n= 15,408). Eighteen studies scored 4 or more points on the Jadad scale.
Pain-free response at two hours:
Zolmitriptan 2.5mg tablets and zolmitriptan 5mg tablets were associated with a statistically significant increase in pain-free response at two hours compared to placebo for both 2.5mg tablets (rate ratio 2.39, 95% CI: 1.75 to 3.27) and 5mg tablets (rate ratio 2.84, 95% CI: 1.17 to 6.89; seven studies).
Zolmitriptan 2.5mg was associated with a statistically significant increase in pain-free response at two hours compared to naratriptan 2.5mg (rate ratio 1.73, 95% CI: 1.10 to 2.72; one study) and a statistically significant decrease in pain-free response at two hours compared to eletriptan 80mg (rate ratio 0.60 (95% CI: 0.49 to 0.74; one study). There was no significant difference in pain-free relief at two hours between zolmitriptan 2.5mg and acetylsalicyclic acid 900mg plus metoclopramide 10mg, almotriptan 12.5mg, eletriptan 40mg or rizatriptan 10mg, sumatriptan 50mg or between zolmitriptan 5mg and sumatriptan 50mg or 100mg.
Headache relief at two hours:
Zolmitriptan 2.5mg tablets and zolmitriptan 5mg tablets were associated with a statistically significant increase in headache relief at two hours compared to placebo for both 2.5mg (rate ratio 1.83, 95% CI: 1.46 to 2.29; nine studies) and 5mg tablets (rate ratio 1.86, 95% CI: 1.19 to 2.90; six studies).
Zolmitriptan 2.5mg was associated with a statistically significant decrease in headache relief at two hours compared to eletriptan 80mg (rate ratio 0.81, 95% CI: 0.73 to 0.90; one study). There was no significant difference in headache relief at two hours between zolmitriptan 2.5mg and acetylsalicyclic acid 900mg plus metoclopramide 10mg, almotriptan 12.5mg, eletriptan 40mg, naratriptan 2.5mg or rizatriptan 10mg and or between zolmitriptan 5mg and sumatriptan 50mg or 100mg.
Significant heterogeneity was found for both headache relief and pain-free response at two hours for zolmitriptan 2.5mg: I2 84.7% (headache relief); and 66.2% (pain-free response). Placebo response rates varied from 22.2% to 58.1% (headache relief) and from 5.9% to 19.8% (pain-free response).
Adverse events:
All formulations of zolmitriptan were associated with a significant increase in the proportion of patients reporting any adverse events compared to placebo for both 2.5mg tablet (risk ratio 1.60, 95% CI: 1.22 to 2.10; 11 studies) and 5mg tablet (risk ratio 2.00, 95% CI: 1.63 to 2.45; seven studies).
Zolmitriptan 2.5mg tablet was associated with a statistically significant increase in adverse events compared to acetylsalicyclic acid 900mg plus metoclopramide 10mg (rate ratio 1.40, 95% CI: 1.13 to 1.73), naratriptan 2.5mg (rate ratio 1.59, 95% CI: 1.10 to 2.30) and rizatriptan 10mg (rate ratio 1.27, 95% CI: 1.02 to 1.58) and a significant decrease in adverse events compared to eletriptan 80mg (rate ratio 0.80, 95% CI: 0.67 to 0.95).
There was no significant difference in adverse events between zolmitriptan 2.5mg tablet and almotriptan 12.5mg, eletriptan 40mg and sumatriptan 50mg and between zolmitriptan 5mg tablet and sumatriptan 50mg or 100mg.
Most comparisons between active agents were based on data from one study.
Results for other outcomes and other specified adverse events were also reported.