However, there are a number of important side-effects associated with this class of drugs. Reviewers looked at propranolol vs. pretreatment baseline and propranolol vs. placebo. Only the placebo comparisons are considered here. This percent was derived from weighted trial scores. However, this should be treated with caution given the methodological weaknesses listed above.
Reviewers state that most trials looked at propranolol use over a six month period.
One trial continued for eight to 16 months, and reported good maintenance. This trial also reported improved migraine ratings when patients were switched to placebo. Comparative figures were not given. Tfelt-Hansen P. Efficacy of beta blockers in migraine. A critical review.