What about flunarizine for migraine prophylaxis?

Flunarizine for Migraine Prophylaxis

Flunarizine at 10 mg/day is an effective second-line medication for migraine prevention with proven efficacy, though it is associated with side effects including sedation, weight gain, and potential depression and extrapyramidal symptoms in elderly patients. 1

Efficacy and Place in Therapy

• Flunarizine (10 mg/day) has proven efficacy in migraine prevention and is commonly used in countries where it is available 1
• Current guidelines position flunarizine as a second-line medication for migraine prophylaxis, after first-line options including beta blockers (atenolol, bisoprolol, metoprolol, propranolol), topiramate, and candesartan 1
• Meta-analysis shows flunarizine reduces headache frequency by approximately 0.4 attacks per 4 weeks compared to placebo 2
• Flunarizine's effectiveness in migraine prevention is comparable to that of propranolol, a first-line agent 2, 3

Dosing Considerations

• The standard effective dose is 10 mg daily, typically administered at night to minimize daytime sedation 1, 4
• Some evidence suggests that a lower dose of 3 mg daily may provide similar efficacy with fewer side effects, though this is not widely adopted in guidelines 5
• Clinical benefit may take 2-3 months to manifest, so an adequate trial period is necessary before determining efficacy 1

Side Effects and Safety Concerns

• Common adverse events include:
  • Sedation/somnolence 1, 4
  • Weight gain 1, 4, 3
  • Abdominal pain 1, 4
• More serious concerns include:
  • Depression, particularly in elderly patients 1, 4
  • Extrapyramidal symptoms, more commonly observed in elderly persons 1, 4
• When compared to propranolol, flunarizine has a different side effect profile - while propranolol commonly causes sleep disturbances, mental changes, and tiredness, flunarizine primarily causes weight gain and sedation 3

Clinical Decision Algorithm

1. Evaluate if patient meets criteria for migraine prophylaxis:

   • Two or more attacks per month with disability lasting 3+ days per month
   • Failure of or contraindication to acute treatments
   • Use of abortive medication more than twice weekly
   • Presence of uncommon migraine conditions (hemiplegic migraine, migraine with prolonged aura) 1

2. Try first-line agents before considering flunarizine:

   • Beta blockers without intrinsic sympathomimetic activity (propranolol, metoprolol, etc.)
   • Topiramate
   • Candesartan 1

3. Consider flunarizine as a second-line option if:

   • First-line agents fail or are contraindicated
   • Patient has no history of depression
   • Patient is not elderly (due to increased risk of extrapyramidal symptoms) 1

4. Initiate at 10 mg daily, preferably at night to minimize sedation 1, 4

5. Continue for at least 2-3 months to properly evaluate efficacy 1

6. Monitor for:

   • Weight gain (most common side effect)
   • Sedation/somnolence
   • Depression (particularly in elderly patients)
   • Extrapyramidal symptoms (particularly in elderly patients) 1, 4

Special Considerations

• Flunarizine appears to be effective in both adults and children with migraine 2
• Consider tapering or discontinuing treatment after a period of stability 1
• Avoid concurrent use with medications that may increase sedation 4
• If using concurrently with NSAIDs like naproxen, monitor for increased gastrointestinal symptoms 4