Antimigraine Drugs
Migraine is a neurological disorder characterized by recurrent moderate to severe headaches, often accompanied by nausea, vomiting, and sensitivity to light and sound.
Classification
- 1. Acute Migraine Treatment (For immediate relief)
- Triptans: Sumatriptan, Rizatriptan
- Ergot Derivatives: Dihydroergotamine (DHE), Ergotamine
- NSAIDs: Ibuprofen, Naproxen
- Antiemetics: Metoclopramide, Prochlorperazine
- 2. Prophylactic (Preventive) Treatment
- Beta Blockers: Propranolol, Metoprolol
- Calcium Channel Blockers (CCBs): Verapamil
- Anticonvulsants: Topiramate, Valproate
- Tricyclic Antidepressants (TCAs): Amitriptyline, Venlafaxine
Pharmacodynamics (Mechanism of Action)
- 1. Triptans (Sumatriptan, Rizatriptan)
- Bind to serotonin (5-HT1B and 5-HT1D) receptors.
- Cause vasoconstriction of dilated cranial blood vessels, relieving migraine.
- 2. Ergot Derivatives (DHE, Ergotamine)
- Stimulate serotonin receptors (5-HT1B and 5-HT1D) and adrenergic receptors.
- Lead to vasoconstriction of cranial blood vessels.
- 3. NSAIDs (Ibuprofen, Naproxen)
- Inhibit cyclooxygenase (COX) enzyme.
- Block prostaglandin production → Reduce inflammation & pain.
- 4. Antiemetics (Metoclopramide, Prochlorperazine)
- Block dopamine receptors in the chemoreceptor trigger zone (CTZ) of the brain.
- Reduce nausea and vomiting associated with migraines.
- 5. Beta Blockers (Propranolol, Metoprolol)
- Block beta-adrenergic receptors.
- Reduce frequency & severity of migraines by stabilizing blood vessel tone.
- 6. Calcium Channel Blockers (Verapamil)
- Prevent calcium entry into neurons → Vasodilation & reduced neuronal excitability.
- 7. Anticonvulsants (Topiramate, Valproate)
- Stabilize electrical activity in the brain.
- Affect neurotransmitters & ion channels → Reduce migraine frequency.
- 8. Tricyclic Antidepressants (TCAs: Amitriptyline, Venlafaxine)
- Affect serotonin & norepinephrine levels.
- Modulate pain pathways, reducing migraine attacks.