Low migraine headache recurrence with naratriptan: clinical parameters related to recurrence

OBJECTIVE: To evaluate clinical parameters that may affect the incidence of headache recurrence or the time to headache recurrence, or both, in migraineurs treated with naratriptan, 2.5-mg tablets. BACKGROUND: The incidence of headache recurrence within 24 hours of treatment with naratriptan, 2.5-mg tablets (17%-28%), is lower than that reported for other currently available selective serotonin agonists. Identifying clinical parameters that influence headache recurrence may further reduce the incidence of headache recurrence or prolong the time to recurrence, or both, for naratriptan-treated patients. METHODS: We examined the effects of three clinical parameters (predose pain severity, headache duration prior to treatment, and relief status 4 hours post dose) on the incidence of and time to headache recurrence across four placebo-controlled naratriptan clinical trials. The impact of these parameters on headache recurrence was examined individually and in combination. RESULTS: Predose pain severity had no effect on the incidence of headache recurrence (overall 23%; moderate 22%, severe 23%). The median time to recurrence was longer for patients with moderate pain before treatment compared with patients with severe pain before treatment (14.5 hours versus 9.3 hours, respectively). Overall time to headache recurrence was 11.8 hours. Patients with headache recurrence reported a longer time until they treated the headache compared with patients without headache recurrence (median, 145 minutes versus 97.5 minutes). Patients who treated headache pain within 3 hours of onset had a lower incidence of headache recurrence (20%) than patients who treated their headache more than 3 hours after onset (28%). Patients with no pain 4 hours post dose had a lower incidence of and a longer time to headache recurrence compared with patients with mild pain 4 hours post dose (17% versus 32%; median, 17.8 hours versus 8.1 hours, respectively). The interaction of all three clinical parameters was significant in predicting headache recurrence. CONCLUSIONS: The overall incidence of headache recurrence is low after naratriptan, 2.5 mg, compared with other currently available selective serotonin agonists. Predose pain severity, time to treatment, and 4-hour relief status appear related to the incidence of or time to headache recurrence, or both. Treating less severe migraine attacks, treating earlier within an attack, and obtaining complete relief post dose may enhance the low incidence of headache recurrence and achieve longer times to recurrence with naratriptan, 2.5 mg.