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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.

[edit] Types of Antiemetics

Antiemetics include:

• 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.
  • Dolasetron (Anzemet) - can be administered in tablet form or in an injection.
  • Granisetron (Kytril, Sancuso) - can be administered in tablet (Kytril), oral solution (Kytril), or in a single transdermal patch to the upper arm (SANCUSO).
  • Ondansetron (Zofran) - administered in an oral tablet form.
  • 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.^{[citation needed]}
• 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.
  • Domperidone
  • Droperidol, haloperidol, chlorpromazine, promethazine, prochlorperazine. Some of these drugs are limited in their usefulness by their extra-pyramidal and sedative side-effects.
  • 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.
  • Alizapride
• Antihistamines (H₁ histamine receptor antagonists), effective in many conditions, including motion sickness, morning sickness in pregnancy, and to combat opiate nausea.
  • Cyclizine
  • Diphenhydramine (Benadryl)
  • Dimenhydrinate (Gravol, Dramamine)
  • Meclizine (Bonine, Antivert)
  • Promethazine (Pentazine, Phenergan, Promacot) Promethazine can be administered via a rectal suppository for adults and children over 2 years of age.
  • Hydroxyzine
• Cannabinoids are used in patients with cachexia, cytotoxic nausea, and vomiting, or who are unresponsive to other agents.
  • Cannabis - Medical marijuana, in the U.S., it is a Schedule I drug.^{[citation needed]}
  • Dronabinol (Marinol) - a Schedule III drug in the U.S.^{[citation needed]}
  • Nabilone (Cesamet) - Put back on the market in late 2006. In the U.S., it is a Schedule II substance.
  • Sativex is an oral spray containing THC and CBD. It is currently legal in Canada and a few countries in Europe but not in legal the U.S.^{[citation needed]}
• Benzodiazepines
  • Midazolam given at the onset of anesthesia has been shown in recent trials to be as effective as ondansetron.^{[citation needed]}
  • Lorazepam said to be very good as an adjunct treatment for nausea along with first line medications such as Compazine or Zofran.^{[citation needed]}
• Anticholinergics
  • Hyoscine (also known as scopolamine)
• Steroids
  • Dexamethasone 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.
• NK1 receptor antagonist
  • Aprepitant (Emend) Commercially available NK1 Receptor antagonist
  • Casopitant Investigational NK1 receptor antagonist
• Other
  • Prochlorperazine (Compazine, Stemzine, Buccastem, Stemetil, Phenotil)
  • Trimethobenzamide; thought to work on the CTZ
  • Ginger
  • Emetrol also claimed to be an effective antiemetic.
  • Propofol given intravenously. It has been used in an acute care setting in hospital as a rescue therapy for emesis.^{[citation needed]}
  • Peppermint claimed to help nausea or stomach pain when added into a tea or peppermint candies.
  • Muscimol purported as such^[1]
  • Ajwain purported to be antiemetic. It is a popular spice in India, Ethiopia and Eritrea.
  • Zolpidem has been reported to be a newer antiemetic used for patients that have been unresponsive to other first-line typical antiemetics.^{[citation needed]}
• Non-pharmaceutical therapies with some evidence of efficacy include acupuncture and hypnosis.

[edit] References

[edit] See also

• Emetic
• Hyperemesis gravidarum
• Chemotherapy