Serotonin receptor blockers

5-HT3 serotonin receptor blockers include Ondansetron and granisetron.

Action:
It blocks 5-HT3 receptors in the periphery (visceral afferent fibers) and in the brain (chemorecptor trigger zone).

Pharmacokinetics:
• Orally or IV
• Prevents vomiting in 50 – 60% of patients treated with Cisplatin.

Clinical Uses:
It is used as prophylaxis of nausea and vomiting associated with cancer chemotherapy.

Side affects:
Headache.

5-HT1c and 5-HT2 receptor blockers include Ketanserin.

Action:

This drug potently blocks vascular α1-adrenoceptors resulting in hypotensive action. It antagonizes platelet aggregation caused by serotonin by blocking 5-HT2 receptors on platelets.

Uses:
It is used in hypertension and vasospastic conditions.