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. They may be used for severe cases of gastroenteritis, especially if the patient is dehydrated.
Antiemetics can also be 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 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) is administered in an oral tablet form, orally dissolving tablet form, orally dissolving film, or in an IV/IM injection.
- Tropisetron (Setrovel, 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) is an antidepressant that also has antiemetic effects and is also a potent histamine H1 receptor antagonist, Ki=1.6 nM.
- 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.
- NK1 receptor antagonist
- Aprepitant (Emend) is a commercially available NK1 Receptor antagonist
- Casopitant is an investigational NK1 receptor antagonist
- Antihistamines (H1 histamine receptor antagonists) are 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.
- Midazolam is given at the onset of anesthesia has been shown in recent trials to be as effective as ondansetron.
- Lorazepam (Ativan) is said to be very good as an adjunct treatment for nausea along with first line medications such as Compazine or Zofran.
- Dexamethasone (Decadron) is given in low dose at the onset of a general anaesthetic is an effective antiemetic. The specific mechanism of action is not fully understood.
- Trimethobenzamide is thought to work on the CTZ
- Ginger contains 5-HT3 antagonists gingerols, shogaols, and galanolactone. Preliminary clinical data suggests ginger may be effective for treatment of nausea and/or vomiting in a number of settings. 
- Emetrol is also claimed to be an effective antiemetic.
- Propofol is given intravenously. It has been used in an acute care setting in hospital as a rescue therapy for emesis.
- Peppermint is claimed to help nausea or stomach pain when added into a tea or peppermint candies.
- Muscimol is purported to have antiemetic activity.
- Ajwain is purported to be antiemetic. It is a popular spice in India, Ethiopia and Eritrea.
- ↑ Zachary A. Flake, Robert D. Scalley, Austin G. Bailey (Mar 1, 2004), "Practical Selection of Antiemetics", Am Fam Physician 69 (5): 1169–1174
- ↑ 2.0 2.1 2.2 http://www.mesotheliomaweb.org/mesothelioma/treatment/chemotherapy/anti-Enausea-treatment/
- ↑ Pae C-U. Low-dose mirtazapine may be successful treatment option for severe nausea and vomiting. Progress in Neuro-Psychopharmacology and Biological Psychiatry [Internet]. 2006 Aug 30 [cited 2013 Sep 27];30(6):1143–5. Available from: http://www.sciencedirect.com/science/article/pii/S0278584606000935
- ↑ Kast R e., Foley K f. Cancer chemotherapy and cachexia: mirtazapine and olanzapine are 5-HT3 antagonists with good antinausea effects. European Journal of Cancer Care [Internet]. 2007 [cited 2013 Sep 27];16(4):351–4. Available from: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2354.2006.00760.x/abstract
- ↑ National Institute of Mental Health. PDSD Ki Database (Internet) [cited 2013 Sep 27]. Chapel Hill (NC): University of North Carolina. 1998-2013. Available from: http://pdsp.med.unc.edu/pdsp.php
- ↑ 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, doi:10.1016/j.ejphar.2005.10.049 Epub 2005 Dec 20
- ↑ Huang, Q.; Iwamoto, Y.; Aoki, S.; Tanaka, N.; Tajima, K.; Yamahara, J.; Takaishi, Y.; Yoshida, M.; Tomimatsu, T.; Tamai, Y. (1991). "Anti-5-hydroxytryptamine3 effect of galanolactone, diterpenoid isolated from ginger". Chemical & pharmaceutical bulletin 39 (2): 397–399. PMID 2054863. doi:10.1248/cpb.39.397.
- ↑ Marx, WM; Teleni L; McCarthy AL; Vitetta L; McKavanagh D; Thomson D; Isenring E. (2013). "Ginger (Zingiber officinale) and chemotherapy-induced nausea and vomiting: a systematic literature review". Nutr Rev 71 (4): 245–54. PMID 23550785. doi:10.1111/nure.12016.
- ↑ Ernst, E.; Pittler, M.H. (1 March 2000). "Efficacy of ginger for nausea and vomiting: a systematic review of randomized clinical trials" (PDF). British Journal of Anesthesia 84 (3): 367–371. PMID 10793599. doi:10.1093/oxfordjournals.bja.a013442. Retrieved 6 September 2006.
- ↑ hoe 2#section1 Muscimol. Chemical Data Sheet, Database of Hazardous Materials, CAMEO chemicals