European Headache Federation (EHF) critical re-appraisal and meta-analysis of oral drugs in migraine prevention - part 4: propranolol

Objective: The aim of this paper is to critically re-appraise the published trials assessing propranolol for migraine prophylaxis. Methods: We report methods and results following the Preferred Reporting Items for Systematic Reviews (PRISMA), by searching MEDLINE, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov for randomized trials of pharmacologic treatments for migraine prophylaxis. We included randomized trials that compared propranolol with placebo for migraine prophylaxis in adults. The outcomes of interest were informed by the Core outcome set for preventive intervention trials in chronic and episodic migraine (COSMIG) and include the proportion of patients who experience a 50% or more reduction in monthly migraine days, the reduction of monthly migraine days, and the number of adverse events leading to discontinuation. We assessed risk of bias by using a modified Cochrane RoB (risk of bias) 2.0 tool and the certainty of evidence by using the GRADE approach. Results: Our search yielded twenty trials (n = 1291 patients) eligible for data synthesis and analysis. The analysis revealed a moderate certainty evidence that propranolol leads to a reduction in monthly migraine days versus placebo (-1.27; 95% CI: -2.25 to -0.3). We found moderate certainty evidence that propranolol increases the proportion of patients who experience a 50% or more reduction in monthly migraine days, compared to placebo with a relative risk of 1.65 (95% CI 1.41 to 1.93); absolute risk difference: 179 more per 1,000 (95% CI 113 to 256). We found high certainty evidence that propranolol increases the proportion of patients who discontinue due to adverse events compared to placebo with a risk difference of 0.02 (95% CI 0.00 to 0.03); absolute risk difference: 20 more per 1,000 (95% CI 0 to 30). Conclusions: The present meta-analysis shows that propranolol has a prophylactic role in migraine, with an overall acceptable tolerability profile. Combining these results with its long-standing use and its global availability at a low cost confirms its role as a first line agent in the prophylaxis of migraine.