Serotonin receptor antagonist

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

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 antidepressant
 Clozapine antipsychotic.  Blocks 5-HT2A, 5-HT2C and D4 receptors. 
 Nefazodone acts primarily as a potent 5-HT2A antagonist. 

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 are used for the treatment of irritable bowel syndrome:

 Alosetron
 Cilansetron

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

Non-selective 5-HT antagonists
Please note, that 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
 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. 
 Reserpine Depletes serotonin stores in the brain, heart, and many other organs and has been used in hypertension and psychosis

See also
 Serotonin receptor agonist

References

External links