• chronic daily headache;
  • transformed migraine;
  • naratriptan;
  • preventive treatment;
  • prophylactic treatment

Objective.—To assess the efficacy, safety, and tolerability of daily naratriptan in the preventive treatment of transformed migraine (TM) refractory to previous first line therapies.

Background.—Limited evidence suggests that the triptans can be used in the preventive treatment of refractory headaches.

Design/Methods.—We included subjects from 18 to 65 years old, with TM, with or without medication overuse (Silberstein and Lipton, 1996). All participants had previously failed at least two preventive medications. Concomitant, preventive medications were allowed if on a stable dose. After the baseline period, all patients received naratriptan 2.5 mg bid. The treatment phase lasted 3 months. The primary endpoint was change in headache frequency per month. Safety assessment included monthly ECGs, complete ophthalmologic exam, and monthly blood tests. Statistical analyses were performed using the intent-to-treat (ITT) population. We also conducted per-protocol (PP) analyses.

Results.—Our ITT population consisted of 30 subjects (79% female, mean age of 46.5 years). Mean headache frequency per month at baseline was 27.1 days and a significant reduction of headache frequency was obtained in 1 month (20.4, P < .001), 2 months (18.9, P < .001), and 3 months (19.0, P < .001). HIT scores were 64.3 at baseline, 57.4 after 1 month (P < .001), 55.7 after 2 months (P < .01), and 60 at 3 months (P < .05). The mean number of days using rescue medication was reduced from 17.7 at baseline, to 9.7 at 3 months (P < .001). Our PP population consisted of 22 subjects, and 54% had fewer than 15 headaches per month at the end of the study (converted to an episodic pattern). No serious adverse events were reported. No significant changes were observed in blood pressure or in heart rate. ECGs and ophthalmologic exam were unchanged from baseline.

Conclusions.—(1) Daily use of naratriptan provided good preventive efficacy in an important subset of subjects with TM refractory to other preventive treatments. (2) The tolerability of this treatment was excellent. (3) Over a short period of time (3 months), no serious adverse events were reported, nor significant changes were found in the ECG or ophthalmologic evaluation.