From the Guidelines
Anti-nausea medications include ondansetron, promethazine, metoclopramide, and dexamethasone, which work by blocking various receptors in the brain and gut that trigger nausea. For adults, typical dosages are:
- Ondansetron: 4-8 mg orally every 8 hours as needed
- Promethazine: 25 mg orally or rectally every 4-6 hours as needed
- Metoclopramide: 10 mg orally up to 4 times daily
- Dexamethasone: 4-5 mg dose has clinical effects similar to the 8-10 mg dose, as shown in a recent meta-analysis with 6696 patients 1 These medications can be used alone or in combination, depending on the severity of nausea and vomiting. Some of these drugs can cause drowsiness, so avoid driving or operating machinery until you know how they affect you. If nausea persists or is accompanied by severe symptoms, consult a healthcare provider. Other antiemetic options include:
- Serotonin antagonists, such as granisetron and tropisetron
- Dopamine antagonists, such as domperidone and metopimazine
- Neurokinin-1 receptor antagonists, such as aprepitant
- Corticosteroids, such as prednisolone and methylprednisolone
- Lorazepam, which is a useful adjunct to antiemetic drugs but is not recommended as a single-agent antiemetic 1 It's essential to note that the choice of antiemetic medication depends on the individual patient's needs and the specific clinical situation, as outlined in the American Society of Clinical Oncology clinical practice guideline update 1.
From the FDA Drug Label
The active ingredient in ondansetron tablets is ondansetron hydrochloride as the dihydrate, the racemic form of ondansetron and a selective blocking agent of the serotonin 5-HT 3receptor type Ondansetron is a selective 5-HT 3receptor antagonist. The antiemetic action of prochlorperazine may mask the signs and symptoms of overdosage of other drugs and may obscure the diagnosis and treatment of other conditions such as intestinal obstruction, brain tumor and Reye’s syndrome
- Ondansetron is an antiemetic medication, used to prevent nausea and vomiting.
- Prochlorperazine is also an antiemetic medication, used to prevent nausea and vomiting. These medications work by blocking the action of serotonin, a natural substance that may cause nausea and vomiting. 2 3 3
From the Research
Antiemetic Medications
Some antiemetic medications include:
- Ondansetron, a specific antagonist of serotonin type 3 (5-HT3) receptors, which has been shown to provide excellent control of nausea and vomiting in patients treated with cisplatin 4
- Metoclopramide, which has been compared to ondansetron in several studies, with ondansetron showing better response rates in some cases 4, 5
- Droperidol, which has been compared to ondansetron in one trial with 129 patients, showing no difference in efficacy 5
Dosage and Administration
The dosage and administration of ondansetron can vary depending on the specific use case, such as:
- 0.15 mg/kg i.v. every four hours for three doses, beginning 30 minutes before antineoplastic therapy, for the prophylaxis of chemotherapy-induced nausea and vomiting in adults 4
- 1 mg, 4 mg, or 8 mg i.v. for the treatment of postoperative nausea and vomiting, with 4 mg being the optimal dose in one study 6
- 8 mg i.v. prior to induction of anaesthesia, which has been shown to reduce postoperative nausea and vomiting in gynaecological patients 7
Efficacy and Safety
The efficacy and safety of ondansetron have been evaluated in several studies, with results showing:
- Ondansetron to be effective in controlling nausea and vomiting in patients receiving cisplatin, cyclophosphamide, and other chemotherapy agents 4, 8
- Ondansetron to have a similar side effect profile to placebo, with adverse effects including headache, constipation, diarrhea, and transient abnormalities in liver function tests 4, 6
- No evidence of a clinically relevant dose-response between 1 mg and 8 mg of ondansetron for the treatment of postoperative nausea and vomiting 5