Objectives: The aim of this study was to evaluate the angiotensin II receptor antagonist candesartan as prophylactic medication in patients with episodic cluster headache.
Methods: This study comprised a prospective, placebo-controlled, double-blind, parallel-designed trial performed in seven centres in Scandinavia. Forty (40) patients with episodic cluster headache (ICHD-2) were recruited and randomised over a five-year period to placebo or 16 mg candesartan in the first week, and placebo or 32 mg candesartan in the second and third week.
Results: The number of cluster headache attacks (primary efficacy variable) during the three-week treatment period was reduced from 14.3 ± 9.2 attacks in week 1 to 5.6 ± 7.0 attacks in week 3 (-61%) in the candesartan group and from 16.8 ± 14.1 attacks in week 1 to 10.5 ± 11.3 attacks in week 3 (-38%) in the placebo group. The difference between the candesartan and placebo group was not significant with the pre-planned non-parametric ranking test, but a post-hoc exact Poisson test, which takes into account the temporal properties of the data, revealed a significant result ( P < 0.0001).
Conclusions: This was a negative trial. Post-hoc statistics suitable to describe the temporal changes in cluster headache indicate that conduction of future larger studies may be justified.
Keywords: Randomised controlled trial; angiotensin; candesartan; cluster headache; headache.