Systematic Review of Pharmacologic Treatment for Migraine Prevention in Adults

BACKGROUND AND OBJECTIVES: This systematic review (SR) provides updated evidence-based conclusions regarding the use of pharmacologic migraine prevention in adults to inform a new joint American Academy of Neurology (AAN) and American Headache Society practice guideline. METHODS: A multidisciplinary panel conducted an SR following the 2017 AAN Clinical Practice Guideline Process Manual. Randomized controlled trials evaluating pharmacologic preventive treatments for adults with episodic or chronic migraine were included. Searches encompassed MEDLINE, Embase, and ClinicalTrials.gov from database inception through June 6, 2024. Studies were screened in duplicate, with dual independent risk-of-bias assessment. Outcomes included change in monthly headache days, ≥50% responder rate, and validated patient-reported quality of life (QOL) measures. Raw mean differences, standardized mean differences, and risk ratios were calculated. A modified Grading of Recommendations Assessment, Development, and Evaluation process was used to classify certainty of evidence. RESULTS: A total of 217 studies met inclusion criteria. For episodic migraine, high-confidence evidence showed that galcanezumab and erenumab are more effective than placebo in reducing headache frequency. Moderate-confidence evidence supported benefit from atogepant, eptinezumab, fremanezumab, propranolol, topiramate, and valproate. Several additional oral agents including amitriptyline, bisoprolol, flunarizine, fluoxetine, levetiracetam, metoprolol, nifedipine, pizotifen, and telmisartan had low-confidence evidence suggesting possible benefit. For chronic migraine, high-confidence evidence supported reductions in headache frequency with fremanezumab, galcanezumab, and onabotulinumtoxinA. Moderate-confidence evidence supported benefit from atogepant, eptinezumab, erenumab, topiramate and valproate. Across both episodic and chronic migraine populations, erenumab, fremanezumab, galcanezumab, eptinezumab, rimegepant, atogepant, topiramate and onabotulinumtoxinA demonstrated improvements in patient-reported QOL outcomes on validated instruments. Evidence comparing active treatments was limited and generally of low or very low confidence, restricting conclusions about comparative effectiveness. DISCUSSION: This SR provides a comprehensive synthesis of evidence on pharmacologic migraine prevention in adults. High- and moderate-confidence findings confirm the efficacy of several established and newer preventive therapies and demonstrate improvements in patient-reported outcomes across multiple validated measures. These conclusions informed the development of evidence-based recommendations, presented in a companion publication, to guide clinicians in selecting preventive medications for adults with episodic and chronic migraine.