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 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. 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 == See also ==