When to Use Flunarizine for Migraine Prevention
Flunarizine should be initiated as a second-line preventive medication for patients with ≥2 migraine attacks per month causing ≥3 days of disability, or when acute medications are used more than twice weekly, particularly after first-line agents (beta-blockers, topiramate, candesartan) have failed or are contraindicated. 1
Specific Indications for Flunarizine
Initiate flunarizine when patients meet any of these criteria: two or more migraine attacks per month producing disability for three or more days, use of acute medications more than twice weekly, failure of or contraindications to acute treatments, or presence of uncommon migraine conditions such as prolonged or atypical migraine aura 2, 1
Consider flunarizine specifically for: chronic migraine, migraine with aura, sporadic hemiplegic migraine, familial hemiplegic migraine, and new daily persistent headache with migrainous features 3
Flunarizine is particularly valuable when first-line preventive medications have failed or are contraindicated, as it has proven efficacy comparable to propranolol and topiramate in adults 1, 3
Position in Treatment Algorithm
First-line preventive medications should be tried first: propranolol (80-240 mg/day), timolol (20-30 mg/day), topiramate, or candesartan 2, 1
Flunarizine is recommended as a second-line option by the American Academy of Neurology, after beta-blockers, topiramate, and candesartan 1
The European Neurology Society supports flunarizine as an effective treatment with significant reduction in attack frequency and severity 1
Dosing and Administration
Start with 10 mg/day, administered preferably at night to minimize sedation 1, 3
Lower doses (3 mg/day) may be considered to reduce side effects while maintaining efficacy, though 10 mg remains the standard dose 4
An adequate trial period of 2-3 months is essential before declaring treatment failure, as clinical benefits may take this long to manifest 1, 5
Some patients may require up to 4 months before efficacy can be judged 5
Expected Efficacy
Flunarizine significantly reduces migraine frequency, duration, and severity, with studies showing an 82% reduction in a corrected migraine index and a 50% reduction in attack frequency during the last 4 weeks of a 16-week treatment period 5, 6
Approximately 76% of patients report clinical benefit, with only 24% reporting no effect 3
Duration of treatment: 64% of patients continue treatment for more than 1 year when effective 3
Adverse Effects and Tolerability
Common adverse effects include: sedation (most common), weight gain, and abdominal pain 1, 3
Depression and extrapyramidal symptoms may occur, particularly in elderly patients 1
Only 10.5% of patients stop treatment due to adverse effects, indicating generally good tolerability at standard doses 3
Doses up to 15 mg are generally well tolerated, though 10 mg remains the recommended starting dose 3
Critical Clinical Pitfalls to Avoid
Do not discontinue flunarizine prematurely: The medication requires 2-4 months to demonstrate full efficacy, and early discontinuation may result in missing therapeutic benefit 1, 5
Do not use flunarizine as first-line therapy: Beta-blockers, topiramate, and candesartan should be tried first unless contraindicated 1
Monitor for mood changes and weight gain: These are the most common reasons for discontinuation and should be discussed with patients before initiating therapy 3
Consider lower doses in patients concerned about side effects: 3 mg/day may provide similar efficacy with reduced adverse effects 4