Infrequent or non-response to oral sumatriptan does not predict response to other triptans--review of four trials

A migraineur can claim to be an infrequent responder ('non-responder') to an oral triptan independent of which triptan he or she is presently using. Four trials of an alternative triptan (zolmitriptan/rizatriptan; eletriptan; naratriptan; almotriptan) in patients with a history of infrequent response to oral sumatriptan were compared and contrasted in terms of study design, patient characteristics, and efficacy and tolerability of the triptan under investigation. Unfortunately, none of the reported studies used an appropriate parallel design, which would have had the non-responding triptan (oral sumatriptan) in one arm and without encapsulation. While the four trials differed in terms of study design (open-label vs. placebo-controlled), definition of sumatriptan 'non-responder' (retrospective vs. prospective) and pain intensity at baseline (30% severe to 70% severe), all four demonstrated that lack of response to sumatriptan did not predict lack of response to an alternative triptan. Changing triptans resulted in 2-h pain-relief rates of 25-81% in patients with a history of poor response to sumatriptan. It can be concluded that migraine patients who respond infrequently to sumatriptan should be switched to a different triptan, as lack of response to one triptan does not predict likelihood of responsiveness to another. A review of the available evidence suggests that almotriptan may be one of the most appropriate choices for an alternative triptan.