What are the appropriate prophylactic medications for migraine prevention, considering the patient’s comorbidities, tolerability, and contraindications?

Prophylactic Medications for Migraine Prevention

For episodic migraine prevention, start with propranolol (80-240 mg/d), metoprolol (20-30 mg/d), amitriptyline (30-150 mg/d), topiramate (up to 100 mg/d), or divalproex sodium (500-1500 mg/d) as first-line agents, selecting based on comorbidities: use topiramate for obesity, amitriptyline for depression or insomnia, beta-blockers for hypertension or anxiety, and valproate for bipolar disorder. 1, 2

When to Initiate Prophylactic Therapy

Consider prophylactic treatment when patients experience:

• Two or more attacks per month producing disability lasting 3+ days
• Contraindication to or failure of acute treatments
• Use of abortive medication more than twice per week (risk of medication overuse headache)
• Presence of uncommon migraine conditions (hemiplegic migraine, prolonged aura, migrainous infarction) 1

First-Line Prophylactic Agents

Beta-Blockers

• Propranolol (80-240 mg/d) and timolol (20-30 mg/d) have the strongest evidence 1
• Metoprolol reduces migraine days by 1.27/month compared to placebo 3
• Best for: Patients with hypertension, anxiety, or no cardiovascular contraindications
• Avoid in: Asthma, heart block, severe peripheral vascular disease, depression

Antidepressants

• Amitriptyline (30-150 mg/d) reduces migraine days by 1.2/month 3
• Best for: Patients with depression, anxiety, insomnia, or chronic pain conditions 4
• Caution: Anticholinergic effects (dry mouth, constipation, weight gain), cardiac conduction abnormalities

Antiepileptic Drugs

• Topiramate reduces migraine days by 1.4/month 3

• Best for: Patients with obesity (causes weight loss) 4

• Caution: Cognitive side effects ("word-finding difficulties"), paresthesias, kidney stones, teratogenic (avoid in pregnancy)

• Divalproex sodium (500-1500 mg/d) or sodium valproate (800-1500 mg/d) 1

• Best for: Patients with bipolar disorder or epilepsy

• Contraindicated: Women of childbearing potential (highly teratogenic), liver disease

Second-Line and Newer Agents

CGRP Monoclonal Antibodies

For patients who fail 2-3 oral preventives:

• Erenumab (1.0-2.5 fewer migraine days/month)
• Fremanezumab (1.3-3.8 fewer migraine days/month)
• Galcanezumab (1.1-3.7 fewer migraine days/month)
• Eptinezumab (0.7-3.2 fewer migraine days/month) 3

These are well-tolerated with minimal side effects but significantly more expensive than oral agents 2, 3

Oral CGRP Antagonists (Gepants)

• Atogepant (0.7-2.4 fewer migraine days/month) effective for both episodic and chronic migraine 3
• Consider when oral preventives fail or are not tolerated 2

Alternative Options (When First-Line Fails)

• Candesartan (ARB): 16 mg/d
• Lisinopril (ACE inhibitor): 10-20 mg/d
• Fluoxetine (SSRI): Limited evidence but may be considered 2

Chronic Migraine (≥15 headache days/month)

First, rule out medication overuse headache (≥15 days/month of simple analgesics or ≥10 days/month of triptans, opioids, or combination analgesics) 4

If MOH is present:

• Abruptly withdraw the overused medication (except opioids—taper these)
• Educate patient that headaches will worsen before improving 4

For chronic migraine prevention:

1. Topiramate (first choice due to cost) 4
2. OnabotulinumtoxinA (155-195 units every 12 weeks) after 2-3 oral preventives fail 4
3. CGRP monoclonal antibodies after multiple oral preventive failures 4

Note: Beta-blockers, candesartan, and amitriptyline lack robust RCT data for chronic migraine specifically, though commonly used in practice 4

Treatment Principles

Dosing Strategy

• Start low, titrate slowly to minimize side effects
• Allow 2-3 months at therapeutic dose before declaring treatment failure 1, 2
• Increase dose gradually until clinical benefit achieved or limited by adverse effects 1

Monitoring and Adjustment

• Use a headache diary to track frequency, severity, disability, and medication use 1, 2
• Switch medications if inadequate response after 2-3 months or earlier if intolerable side effects occur 2
• After 6-12 months of stability, consider tapering or discontinuing preventive therapy 4

Critical Contraindications and Warnings

Pregnancy and Lactation

• Avoid valproate (highly teratogenic—neural tube defects, developmental delays)
• Avoid topiramate (increased risk of cleft lip/palate)
• Safer options: Propranolol, metoprolol (category C), though discuss all risks 5

Medication Overuse Headache

• Threshold varies by drug class:
  • Simple analgesics (NSAIDs, acetaminophen): ≥15 days/month
  • Triptans, opioids, combination analgesics: ≥10 days/month 5
• Never use opioids or butalbital for migraine treatment—high risk of dependency and MOH 5

Cost Considerations

Prioritize less expensive medications first unless contraindicated:

1. Generic oral agents (propranolol, amitriptyline, topiramate, valproate)
2. CGRP antibodies and gepants (reserve for treatment-resistant cases due to high cost) 2

The actual cost varies by insurance coverage and patient circumstances—assess individual economic factors when selecting treatment 2