Serotonin receptor antagonist

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

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 receptors, and thus are known as 5-HT3 antagonists. They are efficacious in 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. Also used in the treatment of migrane.
 * 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