The efficacy of naratriptan in the acute treatment of migraine headaches was evaluated in 3 randomized, double-blind, placebo-controlled trials in adult patients (Trials 1, 2, 3). These trials enrolled adult patients who were predominantly female (86%) and Caucasian (96%) with a mean age of 41 years (range: 18 to 65 years). In all studies, patients were instructed to treat at least 1 moderate to severe headache. Headache response, defined as a reduction in headache severity from moderate or severe pain to mild or no pain, was assessed up to 4 hours after dosing. Associated symptoms such as nausea, vomiting, photophobia, and phonophobia were also assessed. Maintenance of response was assessed for up to 24 hours postdose. A second dose of naratriptan tablets or other rescue medication to treat migraines was allowed 4 to 24 hours after the initial treatment for recurrent headache.

In all 3 trials, the percentage of patients achieving headache response 4 hours after treatment, the primary outcome measure, was significantly greater among patients receiving naratriptan tablets compared with those who received placebo. In all trials, response to 2.5 mg was numerically greater than response to 1 mg and in the largest of the 3 trials, there was a statistically significant greater percentage of patients with headache response at 4 hours in the 2.5-mg group compared

The estimated probability of achieving an initial headache response in adults over the 4 hours following treatment in pooled Trials 1, 2, and 3 is depicted in Figure 1.

Figure 1. Estimated Probability of Achieving Initial Headache Response Within 4 Hours in Pooled Trials 1, 2, and 3a

a The figure shows the probability over time of obtaining headache response (reduction in headache severity from moderate or severe pain to no or mild pain) following treatment with naratriptan tablets. In this Kaplan-Meier plot, patients not achieving response within 240 minutes were censored at 240 minutes.

For patients with migraine-associated nausea, photophobia, and phonophobia at baseline, there was a lower incidence of these symptoms 4 hours following administration of 1-mg and 2.5-mg naratriptan tablets compared with placebo.

Four to 24 hours following the initial dose of study treatment, patients were allowed to use additional treatment for pain relief in the form of a second dose of study treatment or other rescue medication. The estimated probability of patients taking a second dose or other rescue medication to treat migraine over the 24 hours following the initial dose of study treatment is summarized in Figure 2.

Figure 2. Estimated Probability of Patients Taking a Second Dose of Naratriptan Tablets or Other Medication to Treat Migraine Over the 24 Hours Following the Initial Dose of Study Treatment in Pooled Trials 1, 2 and 3a

a Kaplan-Meier plot based on data obtained in the 3 controlled clinical trials (Trials 1, 2, and 3) providing evidence of efficacy with patients not using additional treatments censored at 24 hours.

The plot also includes patients who had no response to the initial dose. Remedication was discouraged prior to 4 hours postdose.

There is no evidence that doses of 5 mg provided a greater effect than 2.5 mg. There was no evidence to suggest that treatment with naratriptan was associated with an increase in the severity or frequency of migraine attacks. The efficacy of naratriptan was unaffected by presence of aura; gender, age, or weight of the subject; oral contraceptive use; or concomitant use of common migraine prophylactic drugs (e.g., beta-blockers, calcium channel blockers, tricyclic antidepressants). There was insufficient data to assess the impact of race on efficacy.