Genetic and biochemical changes of the serotonergic system in migraine pathobiology
BACKGROUND Migraine is the most common neurological condition in developed countries. The abortive treatment of migraine attacks is important both for quality of life and costs associated with illness. Triptans, serotonin 5-HT1B/1D receptor agonists, effectively relieve the pain, disability, and associated symptoms of migraine while improving health-related quality of life. Although a number of direct head-to-head triptan comparisons have been made, data for all possible permutations are not available, and unlikely to ever be so, although in clinical practice such information would be useful. OBJECTIVE We aimed to determine the relative efficacy of all available triptans to abort migraine headache among patients with previous adequate response to migraine treatments. METHODS We included only double-blinded randomized clinical trials comparing triptans to either placebo or another triptan. Our primary outcomes were pain-free response at two hours and 24-hour sustained pain-free response, and our secondary outcomes were headache response at two hours and 24-hour sustained headache response. We used Bayesian multiple treatment comparison meta-analyses of seven triptans used in adult patients to abort migraine attacks. We applied a random-effects analysis with meta-regression adjusting for dose. Results are reported as odds ratios with 95% credible intervals. RESULTS We included data from 74 randomized clinical trials. All triptans were significantly superior to placebo for all outcomes, with the exception of naratriptan for 24-hour sustained pain-free response. Eletriptan consistently yielded the highest treatment effect estimates. For the two-hour endpoints, eletriptan was statistically significantly superior to sumatriptan, almotriptan, naratriptan, and frovatriptan for at least one of the two outcomes. Rizatriptan yielded the second highest treatment effects followed by zolmitriptan. For the 24-hour endpoints, eletriptan was statistically significantly superior to sumatriptan, rizatriptan, almotriptan, and naratriptan for at least one of the two outcomes. Frovatriptan data were not available at that endpoint. Further, the probability that eletriptan is the most likely of all triptans to produce a favorable outcome was 68% for pain-free response at two hours, and 54% for 24-hour sustained pain-free response. CONCLUSION Triptans appear to offer differing treatment effects. In the populations studied eletriptan was most likely to produce pain-free responses that were sustained.