Antiemetic drugs are medicines that help control nausea and vomiting. According to Medicine Net, over-the-counter antiemetics are designed for mild nausea or motion sickness. If you have more severe nausea and vomiting, your healthcare provider can evaluate the cause of your symptoms and prescribe more powerful antiemetic drugs.
Antihistamines
Antihistamines, such as diphenhydramine, hydroxyzine and meclizine, block the effects of histamine, a chemical in your body that makes nausea worse. They can be used to treat mild nausea and some, such as meclizine, are useful for motion sickness, according to the Monthly Prescribing Reference.
Benzamides
Metoclopramide is a benzamide drug, part of a class that blocks the effect of dopamine on the vomiting center of your brain. Since metoclopramide sometimes causes muscle spasms, it is often given along with an antihistamine like diphenhydramine, which reduces these unwanted side effects.
Butyrophenones
Butyrophenones like haloperidol and droperidol also block the effect of dopamine within the body, and are typically given by injection to reduce nausea and vomiting.
Benzodiazepines
Lorazepam and alprazola are two benzodiazepine drugs used to treat nausea and vomiting. Benzodiazapines are also used to treat anxiety and insomnia, and they work best when they're combined with other antiemetics such as serotonin antagonists and corticosteroids, according to the website CancerNausea.com.
Cannabinoids
CancerNausea.com says that cannabinoids, such as dronabinol, affect a part of the brain that plays a role in nausea and vomiting. According to the Monthly Prescribing Reference, cannabinoids come in capsules and help to reduce mild nausea and vomiting.
Corticosteroids
Corticosteroids like dexamethasone and methylprednisolone can be used alone, or in combination with other antiemetic drugs, such as metoclopramide, to make your nausea and vomiting better. According to CancerNausea.com, corticosteroids can be quite effective against the side effects of chemotherapy and radiation therapy.
Phenothiazines
According to Health Line, phenothiazines, such a prochlorperazine, promethazine, and chlorpromazine, keep dopamine from affecting the vomiting center in your brain, and can be highly effective against moderate to severe nausea and vomiting. If you have surgery, your doctor may prescribe a phenothiazine to reduce nausea and vomiting after your procedure.
Serotonin Antagonists
According to CancerNausea.com, serotonin antagonists that block the actions of serotonin on your brain and intestines represent a major development in the treatment of nausea and vomiting. Available only by prescription, serotonin antagonists include ondansetron, dolasetron and granisetron. Various serotonin antagonists are available in pills, transdermal patches, and through IV injection, says Monthly Prescribing Reference.
Neurokinin-1-Receptor Antagonists
Aprepitant is the first antiemetic in the new class of neurokinin-1-receptor antagonists, and it block the action of a chemical known as substance P. According to CancerNausea.com, substance P activates a particular neural pathway in the brain that causes nausea and vomiting. Neurokinin-1-receptor antagonists block the action of substance P and work best when they're given together with a serotonin antagonist and a corticosteroid.
