A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action of serotonin and serotonergic drugss at serotonin (5-HT) receptorss.

Types

5-HT2A antagonists

Antagonists of the 5-HT2A receptor are sometimes used as atypical antipsychotics (contrast with typical antipsychotics, which are purely dopamine antagonists).

They include, but are not limited to:

• Cyproheptadine blocks 5-HT2A, H1 and is a mild anticholinergic.

• Methysergide is a 5-HT2A antagonist and nonselective 5-HT1 receptor blocker. It causes retroperitoneal fibrosis and mediastinal fibrosis.

• Quetiapine blocks 5-HT2A, 5-HT1A, dopamine receptors D1 and D2, histamine receptor H1, and a1 adrenoreceptors.

5-HT2A/2C antagonists

• Ketanserin Antihypertensive. Blocks 5-HT2A, 5-HT2C and Alpha 1 (a1) adrenoreceptors.

• Risperidone antipsychotic

• Trazodone

• Nefazodone

5-HT3 antagonists

Another subclass consists of drugs selectively acting at the 5-HT3 receptorss, and thus are known as 5-HT3 antagonistss. They are effective at treating chemotherapy-induced emesis and postoperative nausea and vomiting.

They include, but are not limited to:

• Dolasetron

• Granisetron

• Ondansetron

• Palonosetron

• Tropisetron

Other 5-HT3 antagonists have been considered for use in the treatment of irritable bowel syndrome:

• Alosetron

• Cilansetron

Also, the antidepressant mirtazapine acts as a 5-HT3 antagonist.

Non-selective 5-HT antagonists

Although some non-selective serotonin antagonists may have a particular affinity for a specific 5-HT receptor (and thus may be listed below e.g., methysergide), they still may also possess a generalised non-selective action.

They include, but are not limited to:

• Chlorpromazine

• Cyproheptadine

• Metergoline

• Methysergide

• Mianserin

• Mirtazapine

• Oxetorone

• Pizotifen

• Propranolol

• Ritanserin

• Spiperone

Antihistamines with antiserotonergic activity

• Carbinoxamine

• Cinnarizine

• Cyproheptadine

• Hydroxyzine

• Methdilazine

• Pizotifen

• Promethazine

• Pizotifen is a 5-HT2C antagonist, H1 blocker and anticholinergic useful in migraine prophylaxis.

• Oxatomide

• Oxetorone Also used in the treatment of migrane.

• Ketotifen

Others

• Fenclonine (para-chlorophenylalanine; PCPA) An inhibitor of serotonin synthesis that has been used in the treatment of carcinoid syndrome.

• Feverfew Is a herb traditionally used for migraines (contains parthenolide).

• Reserpine Depletes serotonin stores in the brain, heart, and many other organs and has been used in hypertension and psychosis

• Gamma-mangostin from Garcinia mangostana

See also

• Serotonin receptor agonist

References

External links