Certain types of chemotherapy agents used to treat cancer also cause nausea and vomiting in many patients. The frequency of nausea and/or vomiting, also known as emesis, depends on the chemotherapy type, with high risk drugs causing emesis 90 percent of the time and minimal risk drugs causing emesis less than 10 percent of the time, the National Cancer Institute explains. Anti nausea drugs, also called anti emetics, of different types are given before treatment and continuing for several days after chemotherapy to reduce nausea and vomiting, the Mayo Clinic states.
Seratonin Antagonists
Seratonin antagonists are a class of drugs used to prevent and treat nausea and vomiting after chemotherapy. These drugs work by blocking vomiting receptors in the brain and intestine, according to CancerNausea.com. Drugs in this class include Aloxi (palonosetron), Anzemet (dolasetron), Kytril (granisetron) and Zofran (ondansetron). Potential side effects of these drugs include headache, fever, constipation and diarrhea. All but Aloxi can be taken orally.
Dopamine Agonists
Dopamine agonists, which include Reglan (metoclopramide), Haldol (haloperidol) and Compazine (prochlorperazine) are drugs that block dopamine effects in the vomiting center of the brain. Reglan also helps move food through the stomach more quickly, which reduces the chance of nausea developing, CancerNausea.com reports. All dopamine agonists can cause spasms, uncontrollable body movements, as well as drowsiness. Restlessness or an inability to sit still may also affect people taking these drugs. Benadryl may help decrease spasms and restlessness. Haldol and Compazine may also cause low blood pressure, while Reglan may cause diarrhea.
Corticosteroids
Corticosteroid medications may be given alone but are most often given in addition to other anti-emetics to reduce nausea and vomiting associated with chemotherapy, the National Cancer Institute states. Steroids decrease nausea by decreasing prostaglandin activity in the brain. Side effects of corticosteroids include increased blood sugar, difficulty sleeping, excitability, stomach irritation and facial flushing, the University of California San Francisco reports.
Other Medications
Medications used to treat allergic reactions and anxiety are also helpful in decreasing nausea and vomiting after chemotherapy when used in conjunction with anti-emetics. Drugs used include Ativan (lorazepam) and Xanax (alprazolam), anti-anxiety drugs, and Benadryl (diphenhydramine) an antihistamine. Drowsiness is a common side effect of all these medications.
