NEW YORK (Reuters Health) – Patients with acute migraine who find sumatriptan ineffective may have a better response to rizatriptan, according to a study reported in Cephalalgia online November 15.

In their introduction, the authors note that up to 40% of migraine patients do not respond to sumatriptan, but this does not predict non-response to other triptans. However, “No triptan has been tested in a population of non-responders to sumatriptan 100 mg.”

Dr. Jeffrey L Seeburger with Merck & Co. in Upper Gwynedd, Pennsylvania therefore first tested patients with a history of migraine for response to 100 mg sumatriptan and identified 102 who continued to have moderate/severe pain 2 hours after dosing. These patients were then entered in a double-blind crossover trial of rizatriptan. That is, the participants treated two migraine attacks with rizatriptan 10-mg ODT (orally disintegrating tablet) and one with placebo in randomly assigned order.

The primary endpoint of pain relief at 2 hours was significantly greater (p<0.001) with rizatriptan (51% of attacks) compared with placebo (20%), according to the report. Freedom from pain at 2 hours was also significantly better with rizatriptan than placebo (22% of attacks vs. 12%), as was sustained pain freedom from 2–24 hours, the investigators found. Rizatriptan was generally well tolerated. Adverse events were mostly mild and were experienced by 18 of the patients following rizatriptan treatment and by 3 after placebo. “Migraine patients may demonstrate a variable response to any particular member of the triptan class. Consequently, clinicians must manage migraine treatment with triptans by offering non-responders alternate triptans that might work well for them,” Dr. Seeburger and colleagues note, and they conclude: “The current study has demonstrated that treatment with rizatriptan is an effective and well-tolerated option for migraine patients who do not respond to sumatriptan.” The study was funded by Merck. Reference:
Efficacy and tolerability of rizatriptan for the treatment of acute migraine in sumatriptan non-responders

Cephalalgia 2010.