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An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer.
Anti-emetics are also used for morning sickness, but there is little information about the effect on the fetus, and doctors prefer not to use them unless it is strictly necessary.
Types of antiemetics 
- 5-HT3 receptor antagonists – these block serotonin receptors in the central nervous system and gastrointestinal tract. As such, they can be used to treat post-operative and cytotoxic drug nausea & vomiting. However, they can also cause constipation or diarrhea, dry mouth, and fatigue. 
- Dolasetron (Anzemet) - can be administered in tablet form or in an injection.
- Granisetron (Kytril, Sancuso) - can be administered in tablet (Kytril), oral solution (Kytril), injection D(Kytril), or in a single transdermal patch to the upper arm (SANCUSO).
- Ondansetron (Zofran) - administered in an oral tablet form, oral dissolving tablet form, or in an injection.
- Tropisetron (Navoban) - can be administered in oral capsules or in injection form.
- Palonosetron (Aloxi) - can be administered in an injection or in oral capsules.
- Mirtazapine (Remeron), an antidepressant that also has antiemetic effects.  Is also a potent histamine H1 antagonist, Ki=5.1nM. 
- Dopamine antagonists act in the brain and are used to treat nausea and vomiting associated with neoplastic disease, radiation sickness, opioids, cytotoxic drugs and general anaesthetics. Side effects include muscle spasms and restlessness. 
- Droperidol, haloperidol, chlorpromazine, promethazine, prochlorperazine. Some of these drugs are limited in their usefulness by their extra-pyramidal and sedative side-effects.
- Prochlorperazine (Compazine, Stemzine, Buccastem, Stemetil, Phenotil)
- Metoclopramide (Reglan) also acts on the GI tract as a pro-kinetic, and is thus useful in gastrointestinal disease; however, it is poor in cytotoxic or post-op vomiting. also a 5-HT3 receptor antagonists
- NK1 receptor antagonist
- Aprepitant (Emend) Commercially available NK1 Receptor antagonist
- Casopitant Investigational NK1 receptor antagonist
- Antihistamines (H1 histamine receptor antagonists), effective in many conditions, including motion sickness, morning sickness in pregnancy, and to combat opioid nausea.
- Cannabinoids are used in patients with cachexia, cytotoxic nausea, and vomiting, or who are unresponsive to other agents. These may cause changes in perception, dizziness, and loss of coordination. 
- Dexamethasone (Decadron) given in low dose at the onset of a general anaesthetic is an effective anti-emetic. The specific mechanism of action is not fully understood.
- ^ Zachary A. Flake, Robert D. Scalley, Austin G. Bailey (2004 Mar 1st), "Practical Selection of Antiemetics", Am Fam Physician 69 (5): 1169–1174
- ^ a b c http://www.mesotheliomaweb.org/mesothelioma/treatment/chemotherapy/anti-Enausea-treatment/
- ^ PMID=8930006
- ^ | PMID=12109911
- ^ Abdel-Aziz H, Windeck T, Ploch M, Verspohl EJ. (2006-01-13), "Mode of action of gingerols and shogaols on 5-HT3 receptors: binding studies, cation uptake by the receptor channel and contraction of isolated guinea-pig ileum.", Eur J Pharmacol. 530 (1-2): 136–43, PMID 16364290 Epub 2005 Dec 20
- ^ hoe 2#section1 Muscimol. Chemical Data Sheet, Database of Hazardous Materials, CAMEO chemicals
See also