SEARCH RESULTS FOR: 5HT3-Antagonists

5HT3 Antagonists

5-HT3 Antagonists: Mechanism of action and adverse side effects A class of medications that are used for the prevention and treatment of nausea and vomiting caused by chemotherapy, radiation, or postoperatively. Authors: Arzina Jaffer Madison Amyotte Reviewers: Jasleen Brar Mao Ding Karl Darcus* * MD at time of publication ↓ Postoperative nausea & vomiting Central Actions Binds to 5-HT3 (serotonin) receptors in the area postrema within the brainstem containing the chemoreceptor trigger zone ↓ Binding of serotonin which is released from the raphe nucleus in the brainstem ↓ Stimulation of vomiting center (medulla) supressing the vomiting reflex ↓ Stimulation of vagus nerve resulting in ↓ signals to chemoreceptor trigger zone ↓ Abdominal pain signals to the brain ↓ Levels of serotonin uptake in gastrointestinal tract ↓ Stimulation of gastrointestinal tract, diaphragm, and abdominal muscles Peripheral Actions Binds to 5-HT3 (serotonin) receptors on the vagus nerve terminals Other Actions Unknown mechanism for patients with significant cardiac history (e.g., congenital long QT syndrome, bradycardia, electrolyte abnormalities) Unknown mechanism Unknown mechanism ↓ Binding of serotonin which is released from enterochromaffin cells in the gastrointestinal tract Potential blockage of K+ channels in the heart ↓ Visceral sensation associated with irritable bowel syndrome ↓ Colonic motility slowing the rate of digestion ↓ Diarrhea Constipation Alters depolarization and repolarization of the heart Prolongation of QT interval Headache Drowsiness Torsades de Pointes arrhythmia Cardiac arrest Death Rare complications Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published September 6, 2023 on www.thecalgaryguide.com