Preventive pharmacologic treatments for episodic migraine in adults.

Objectives: Systematic review of preventive pharmacologic treatments for community-dwelling adults with episodic migraine.

Data Sources: Electronic databases through May 20, 2012.

Eligibility Criteria: English-language randomized controlled trials (RCTs) of preventive drugs compared to placebo or active treatments examining rates of ≥50 % reduction in monthly migraine frequency or improvement in quality of life.