What are alternative prophylactic medications for vestibular migraines when propranolol and amitriptyline are not suitable?

Alternative Prophylactic Medications for Vestibular Migraines

When propranolol and amitriptyline are not suitable options for vestibular migraine prophylaxis, topiramate, candesartan, and flunarizine are the most effective alternative medications to consider. 1, 2

First-Line Alternatives

Topiramate

• Dosage: Start at 25mg daily, gradually increase to 50-100mg daily
• Efficacy: Reduces vestibular symptom intensity by approximately 45.8 points on visual analog scale 3
• Benefits: Particularly beneficial for patients with obesity 2
• Side effects: Paresthesias, weight loss, cognitive slowing, nephrolithiasis
• Contraindications: Pregnancy, lactation, glaucoma, nephrolithiasis 1

Candesartan

• Dosage: 16-32mg oral daily
• Efficacy: Recommended as first-line by Nature Reviews Neurology 1
• Benefits: Better tolerated than beta-blockers in patients with asthma or depression
• Side effects: Hypotension, dizziness, hyperkalemia
• Contraindications: Co-administration of aliskiren 1

Second-Line Alternatives

Flunarizine

• Dosage: 5-10mg oral once daily
• Efficacy: Significantly reduces vertigo intensity, duration, and frequency 4
• Benefits: Effective for both vestibular symptoms and headache 5
• Side effects: Weight gain, sedation, depression
• Contraindications: Parkinsonism, depression 1

Sodium Valproate

• Dosage: 600-1500mg oral once daily
• Efficacy: Recommended as second-line by Nature Reviews Neurology 1
• Important restriction: Strictly contraindicated in women of childbearing potential due to teratogenicity 1, 2
• Side effects: Weight gain, hair loss, tremor, liver dysfunction
• Contraindications: Liver disease, thrombocytopenia, pregnancy 1

Third-Line Options

CGRP Monoclonal Antibodies

• Options: Erenumab, fremanezumab, galcanezumab, eptinezumab
• Efficacy: Efficacy should be assessed after 3-6 months of treatment 1
• Indication: Consider when other preventive medications have failed or are contraindicated 1
• Administration: Subcutaneous injection (monthly or quarterly depending on agent)

OnabotulinumtoxinA (Botox)

• Indication: Particularly effective for chronic migraine (≥15 headache days/month) 2
• Administration: Administered by specialists according to protocol
• Efficacy assessment: Should be evaluated after 6-9 months of treatment 1

Treatment Algorithm

1. Initial assessment:

   • Confirm diagnosis of vestibular migraine using Bárány Society/International Headache Society criteria
   • Document frequency, intensity, and duration of episodes
   • Identify contraindications to specific medications

2. First medication trial (if propranolol and amitriptyline unsuitable):

   • For patients without contraindications: Topiramate or Candesartan
   • For patients with obesity: Topiramate preferred
   • For patients with hypertension: Candesartan preferred

3. Evaluation of efficacy:

   • Assess after 2-3 months of optimized therapy 2
   • Treatment success: ≥50% reduction in monthly vestibular migraine episodes

4. If first trial fails:

   • Switch to flunarizine (if no depression or parkinsonism)
   • Consider sodium valproate for men only

5. If second trial fails:

   • Consider CGRP monoclonal antibodies or onabotulinumtoxinA
   • Refer to headache or neurotology specialist

Clinical Pearls

• Multiple studies show no significant difference in efficacy between the various prophylactic medications for vestibular migraine 5, 3
• The time of vestibular symptoms appears to increase the benefit with prophylactic treatment 5
• Combining medications did not show statistically significant improvement compared to monotherapy 5
• Treatment failure with one class does not predict failure with other drug classes 1
• Consider pausing preventive medication after 6-12 months of successful treatment 1

Common Pitfalls to Avoid

• Failing to recognize that vestibular migraine often doesn't meet criteria for basilar-type migraine in the International Headache Society classification 6
• Abandoning treatment too early before efficacy can be properly assessed
• Not considering comorbidities when selecting prophylactic medication
• Using sodium valproate in women of childbearing potential

Remember that prophylactic treatment should be considered in patients who are adversely affected by vestibular migraine on ≥2 days per month despite optimized acute treatment 1.