What are the first-line preventive medications for patients with more than 18 migraines per month?

First-Line Preventive Medications for Patients with >18 Migraines Per Month

Beta blockers (propranolol, timolol), topiramate, or candesartan should be used as first-line preventive medications for patients experiencing more than 18 migraines per month. 1, 2

Indications for Preventive Therapy

Patients with >18 migraines per month clearly meet all standard criteria for preventive therapy:

• Experiencing ≥2 migraine days per month with significant disability 1, 2
• High frequency of attacks causing substantial disability 3
• Risk of medication overuse headache from frequent use of acute medications 2

First-Line Medication Options

Beta Blockers

• Propranolol (80-240 mg/day) and timolol (20-30 mg/day) have strong evidence supporting efficacy 1, 2
• Common side effects include dizziness, fatigue, and insomnia, but are generally well-tolerated 1
• Particularly useful in patients with comorbid hypertension 2

Topiramate

• Recommended dose is 100 mg/day (typically 50 mg twice daily) 2, 4
• Start at low dose (25 mg) and titrate slowly to minimize side effects 3
• Efficacy demonstrated in multiple large randomized controlled trials 4, 5
• Particularly beneficial for patients concerned about weight gain, as it may cause weight loss 4
• Common side effects include paresthesia, cognitive dysfunction, and decreased appetite 6, 5

Candesartan

• Effective first-line option, particularly useful in patients with comorbid hypertension 2
• Generally well-tolerated with fewer side effects than some other options 2

Second-Line Options

If first-line treatments fail after an adequate trial (2-3 months), consider:

• Flunarizine 1
• Amitriptyline (30-150 mg/day) - may be particularly effective for patients with mixed migraine and tension-type headache 1
• Sodium valproate (800-1500 mg/day) - STRICTLY CONTRAINDICATED in women of childbearing potential due to teratogenic effects 1, 3

Third-Line Options

• CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab, eptinezumab) - reserved for patients in whom other preventive medications have failed 1
• OnabotulinumtoxinA - FDA approved for chronic migraine (≥15 headache days per month), requires assessment after 6-9 months 1, 7

Implementation Strategy

1. Start with low dose of chosen medication and titrate slowly to minimize side effects 1, 3
2. Continue for 2-3 months before assessing efficacy (6-9 months for onabotulinumtoxinA) 1, 2
3. Monitor closely using headache diaries to track frequency, severity, and medication use 3
4. If ineffective after adequate trial, switch to alternative first-line agent or move to second-line options 1
5. Consider pausing successful treatment after 6-12 months to assess continued need 1

Common Pitfalls to Avoid

• Inadequate trial duration - efficacy may not be apparent for 2-3 months 3
• Starting with too high a dose - leads to poor tolerability and discontinuation 2
• Failing to recognize medication overuse - can interfere with preventive treatment 2, 3
• Ignoring contraindications - particularly valproate in women of childbearing potential 1

Non-Pharmacological Adjuncts

Consider as adjuncts to medication or when medications are contraindicated:

• Neuromodulatory devices 1
• Biobehavioral therapy 1
• Acupuncture 1

These options have some supporting evidence but generally less robust than pharmacological approaches for high-frequency migraine.