Antimigraine medication

Question 1

MOA of sumatriptan

Answer 1

• Selective vascular serotonin 5-HT1D receptor agonist
• Selectively constricts the carotid arterial circulation, but does not alter cerebral blood flow (only affects meninges, not blood flow to brain)
• Inhibits trigeminal nerve activity

Question 2

indication of sumatriptan

Answer 2

• Acute treatment of migraine with or without aura

Question 3

PK of sumatriptan

Answer 3

• Route: Oral, nasal, IV
• A: rapidly absorbed
• D: low plasma protein binding
• E: oxidative metabolism mediated by MAO

Question 4

Contraindication of sumatriptan

Answer 4

• Hypersensitivity to triptans
• Concurrent administration with MAOi (Isocarboxazid, Phenelzine, Selegiline, Tranylcypromine)
• Myocardial infarct

Question 5

ADR of sumatriptan

Answer 5

Common
- Dysgeusia (unpleasant taste), transient BP increase, flushing, sensation of cold, pressure, tightness

Rare
- Minor disturbances in liver function tests

Question 6

MOA of cafergot

Answer 6

• Stimulating alpha adrenergic and 5 HT receptors, esp 5HT1B and 5HT1D receptors
• Leading to vasoconstriction
• Tonic action on vascular smooth muscles in the external carotid network

Question 7

Indication of cafergot

Answer 7

• Acute treatment of migraine

Question 8

PK of cafergot

Answer 8

• Rapidly absorbed, peak 1.5-2h
• High plasma protein binding
• Low absolute bioavailability 2-5%
• M: Inhibits CYP3A
• DDI: other CYP3A inhibitors like macrolides  elevated exposure to ergot toxicity leading to vasospasm and tissue ischaemia

Question 9

ADR of cafergot

Answer 9

Common
- Nausea, vomiting
Rare
- Hypersensitivity, MI, ergotism (vascular ischaemia)

Question 10

contraindications of cafergot

Answer 10

• Other vasoconstrictor agents
• Ergot alkaloids
• Sumatriptan
• 5HT1 agonists

Question 11

MOA of erenumab

Answer 11

• Antibodies which blocks CGRP receptors

Question 12

Indication of erenumab

Answer 12

• Prophylaxis of migraine in adults who have at least 4 migraine days per month

Question 13

PK of erenumab

Answer 13

• Route: SQ monthly
• Clinical benefit in 3 months
• Linear kinetics at therapeutics as CGRP receptor binding is saturated

Question 14

ADR of erenumab

Answer 14

• Hypersensitivity
• Injection site reactions
• Constipation
• Pruritis