Prophylaxis of migrane kd tripathi

Reading File

Finding Sources

Reading File

Loading Image

Reading File

I have enough rich content now. Let me compile the comprehensive answer on migraine prophylaxis as covered by KD Tripathi-style pharmacology texts (using Lippincott, Katzung, Bradley & Daroff as authoritative sources).

Prophylaxis of Migraine - KD Tripathi Style

Indications for Prophylaxis

Prophylactic (preventive) therapy is indicated when:

Attacks occur 2 or more times per month
Headaches are severe, prolonged, or disabling (impair daily functioning)
Acute abortive therapy is contraindicated, overused, or ineffective
Headaches are complicated by serious neurologic signs (hemiplegic migraine, migraine with prolonged aura)
Menstrual migraine with predictable timing

The goal is to reduce attack frequency, severity, and duration by at least 50%.

Drugs Used in Migraine Prophylaxis

Drugs used in the treatment and prophylaxis of migraine headaches - Lippincott Illustrated Reviews Pharmacology

1. Beta-Blockers (Drugs of Choice)

Propranolol and metoprolol are the first-line drugs of choice for migraine prophylaxis.

Drug	Dose
Propranolol	40-240 mg/day in divided doses
Metoprolol	100-200 mg/day
Timolol	20-40 mg/day (FDA approved)
Atenolol	50-100 mg/day
Nadolol	20-240 mg/day

Mechanism: Blockade of beta-adrenergic receptors reduces trigeminovascular activation and sympathetic tone. Also modulate serotonergic transmission.

Note: Beta-blockers with intrinsic sympathomimetic activity (ISA) like pindolol are not effective for migraine prophylaxis.

Contraindications: Asthma, COPD, heart block, depression, diabetes (masks hypoglycemia).

2. Antiepileptic Drugs (AEDs)

Valproate / Divalproex Sodium (Sodium Valproate)

Dose: 500-1750 mg/day in divided doses
50% of patients show ≥50% reduction in migraine frequency
Mechanism: Enhances GABA, reduces cortical hyperexcitability and neurogenic inflammation
Side effects: Sedation, weight gain, hair loss, tremor, increased liver enzymes, thrombocytopenia, neural tube defects (teratogenic)
Contraindicated in pregnancy (neural tube defects)

Topiramate

Dose: 75-200 mg/day (start at 15-25 mg/week, titrate slowly)
Evidence from large randomized controlled trials
Mechanism: Blocks Na+ channels, enhances GABA, blocks kainate/AMPA glutamate receptors, inhibits carbonic anhydrase
Side effects: Cognitive impairment ("dopamax"), paresthesia, weight loss, kidney stones (calcium phosphate)
Slow titration essential to avoid precipitating depression

Gabapentin

Dose: 900-2400 mg/day
Limited evidence; useful when migraine co-exists with neuropathic pain, back pain, or peripheral neuropathy
Side effects: Dizziness, sedation

3. Tricyclic Antidepressants (TCAs)

Amitriptyline is the most studied and widely used.

Dose: 10-150 mg at night
Effective even in patients without depression
Mechanism: Blocks serotonin and norepinephrine reuptake; also has antihistamine and anticholinergic effects
Side effects: Sedation, dry mouth, urinary retention, weight gain, cardiac arrhythmias
Also used: Nortriptyline (better tolerated, fewer anticholinergic effects)

SNRIs: Venlafaxine (75-150 mg/day) is an alternative, particularly in patients with comorbid anxiety/depression.

Note: SSRIs (fluoxetine, sertraline) have limited evidence for migraine prophylaxis.

4. Calcium Channel Blockers

Flunarizine (not available in USA)

Dose: 5-10 mg at night
Very effective - reduces both frequency and severity
Drug of choice in many countries (India, Europe)
Mechanism: Non-selective calcium channel blocker + dopamine D2 antagonist
Side effects: Weight gain, sedation, depression, extrapyramidal symptoms (parkinsonism with long-term use)

Verapamil

Has modest efficacy in migraine prophylaxis
Particularly useful in migraine with aura and cluster headaches
Dose: 240-480 mg/day

Note: Nifedipine and amlodipine are less effective.

5. OnabotulinumtoxinA (Botox)

Approved for chronic migraine (≥15 headache days/month for >3 months)
Given as 31 fixed-site injections (155 units) into head/neck muscles every 12 weeks
Mechanism: Inhibits release of CGRP and substance P from peripheral sensory nerve terminals
Supported by two large multicenter placebo-controlled RCTs (PREEMPT 1 & 2)

6. CGRP-Targeted Therapies (Newer Agents)

Calcitonin gene-related peptide (CGRP) plays a key role in migraine pathophysiology. Blocking CGRP or its receptor is a major advance in migraine prevention.

Anti-CGRP Monoclonal Antibodies

Drug	Target	Route	Frequency
Erenumab	CGRP receptor	SC	Monthly
Galcanezumab	CGRP ligand	SC	Monthly
Fremanezumab	CGRP ligand	SC	Monthly or quarterly
Eptinezumab	CGRP ligand	IV	Quarterly

Reserved for patients inadequately controlled by oral agents
Very expensive; used as second-line when oral prophylaxis fails

Oral CGRP Receptor Antagonists (Gepants)

Atogepant and Rimegepant - approved for prevention of migraine
Administered orally, well tolerated
Side effects: nausea, somnolence (low incidence)

7. Serotonin Antagonists (Older Agents)

Methysergide (no longer available in USA/Canada)

Historically very effective; peripheral serotonin antagonist + central agonist
Serious side effect: retroperitoneal, pulmonary, and cardiac fibrosis (drug holiday every 6 months was mandatory)

Cyproheptadine

Peripheral serotonin + H1-antihistamine antagonist
Primarily used in pediatric migraine
Available as syrup for children who cannot swallow tablets
Side effects: Drowsiness, significant weight gain

8. Other Agents

Agent	Dose	Notes
Riboflavin (B2)	400 mg/day	Small RCT showed efficacy; minimal side effects; effect takes 3 months
Magnesium	600 mg/day (chelated or slow-release)	Mixed evidence; diarrhea, gastric irritation
Butterbur (Petasites)	150 mg/day	Evidence from clinical trials but potential hepatotoxicity
Coenzyme Q10	300 mg/day	Some evidence; well tolerated
Aspirin/NSAIDs	325 mg every other day	Modest benefit; especially for menstrual migraine

Perimenstrual (Cyclic) Prophylaxis for Menstrual Migraine

For women with predictable menstrual migraines, short-course perimenstrual prophylaxis (days -3 to +3 of cycle) can be used:

NSAIDs: Naproxen sodium 550 mg BD, mefenamic acid 250 mg TDS, ketoprofen 75 mg TDS
Triptans: Frovatriptan (long t½ of 27 hours - preferred), naratriptan, zolmitriptan
Ergots: Ergotamine tartrate + caffeine 1 mg qhs

Summary Table - First Line vs Second Line

Category	Drug	Status
Beta-blocker	Propranolol, Metoprolol	1st line (DOC)
AED	Topiramate, Valproate	1st line
TCA	Amitriptyline	1st line
Ca2+ channel blocker	Flunarizine, Verapamil	2nd line
SNRI	Venlafaxine	2nd line
Botox	OnabotulinumtoxinA	Chronic migraine only
Anti-CGRP mAb	Erenumab, Galcanezumab	Refractory cases
Oral gepants	Atogepant, Rimegepant	Newer; preventive use

Key Points for Exams (KD Tripathi Style)

Drug of choice for migraine prophylaxis = Propranolol (a non-selective beta-blocker without ISA)
Valproate is contraindicated in pregnancy - risk of neural tube defects
Flunarizine causes weight gain + extrapyramidal symptoms (depression, parkinsonism)
Topiramate causes weight loss - useful in obese patients; but can cause cognitive blunting
Amitriptyline is effective even in non-depressed migraineurs
Methysergide can cause fibrosis (retroperitoneal, pulmonary, cardiac) - requires 1-month drug holiday every 6 months
Cyproheptadine is preferred in children (syrup formulation)
CGRP monoclonal antibodies are the newest class - given SC monthly; reserved for refractory cases
Beta-blockers with ISA (pindolol, acebutolol) are NOT effective
Prophylaxis is considered successful if attack frequency reduces by ≥50%

Sources: Lippincott Illustrated Reviews Pharmacology, p.1324; Katzung's Basic and Clinical Pharmacology, 16th ed., p.456; Bradley and Daroff's Neurology in Clinical Practice, pp.2479-2482

This is a shared conversation. Sign in to Orris to start your own chat.