What are the medications for nausea (vomiting)?

From the Guidelines

For nausea, the most effective medication is ondansetron (Zofran) 4-8mg taken orally every 8 hours as needed, as it has been shown to be highly effective in reducing nausea and vomiting in various studies, including those on gastroparesis and chemotherapy-induced nausea 1.

Medication Options

The following medications are available for treating nausea:

• Ondansetron (Zofran) 4-8mg taken orally every 8 hours as needed
• Promethazine (Phenergan) 12.5-25mg every 4-6 hours
• Dimenhydrinate (Dramamine) 50-100mg every 4-6 hours
• Ginger supplements (250mg four times daily)
• Pepto-Bismol (525mg every 30-60 minutes as needed, up to 8 doses daily)

Mechanism of Action

These medications work by blocking different receptors involved in triggering nausea, either in the brain's vomiting center or in the gut. For example, ondansetron blocks serotonin receptors in the chemoreceptor trigger zone, while promethazine and dimenhydrinate block dopamine receptors in the brain.

Treatment Considerations

When treating nausea, it is essential to consider the underlying cause and severity of the symptoms. For motion sickness, taking medication 30-60 minutes before travel is recommended. If nausea persists beyond 48 hours, is accompanied by severe abdominal pain, high fever, or signs of dehydration, medical attention should be sought as these could indicate a more serious condition requiring different treatment 1.

Additional Options

Other medications that may be considered for treating nausea include:

• Granisetron (1 mg bid)
• Prochlorperazine (5-10 mg qid)
• Scopolamine (1.5 mg patch every 3 days)
• Aprepitant (80 mg/day)
• Domperidone (10 mg tid, although availability is limited in the US) 1

From the FDA Drug Label

In two placebo-controlled, double-blind trials (one conducted in the US and the other outside the US) in 865 females undergoing inpatient surgical procedures, ondansetron tablets 16 mg as a single dose or placebo was administered one hour before the induction of general balanced anesthesia (barbiturate, opioid, nitrous oxide, neuromuscular blockade, and supplemental isoflurane or enflurane), ondansetron tablets were significantly more effective than placebo in preventing postoperative nausea and vomiting. In a placebo-controlled trial conducted in 468 males undergoing outpatient procedures, a single 4-mg intravenous ondansetron dose prevented postoperative vomiting over a 24-hour period in 79% of males receiving drug compared with 63% of males receiving placebo (P <0. 001).

The medications for nausea (vomiting) are:

• Ondansetron tablets: 16 mg as a single dose, or 4-8 mg three times a day
• Ondansetron IV: 4 mg as a single dose, or 0.1 mg/kg for pediatric patients weighing 40 kg or less 2 3

From the Research

Medications for Nausea and Vomiting

The following medications are used to treat nausea and vomiting:

• Droperidol: commonly used in the past, but its use is limited due to the potential for QT prolongation 4
• Promethazine: more sedating than other comparative agents and has the potential for vascular damage upon intravenous administration 4
• Prochlorperazine: patients must be monitored for akathisia that can develop at any time over 48 h post administration 4
• Metoclopramide: patients must be monitored for akathisia that can develop at any time over 48 h post administration 4
• Ondansetron: as effective as promethazine, and is not associated with sedation or akathisia 4, 5, 6

Efficacy of Medications

Studies have compared the efficacy of these medications:

• Ondansetron was found to be safe and effective for the treatment of nausea and vomiting in the emergency department setting 4, 5
• Metoclopramide and ondansetron were found to have similar efficacy in reducing nausea severity, with no significant difference from placebo 6
• Ondansetron was found to be more effective than metoclopramide in the prophylaxis of chemotherapy-induced nausea and vomiting 7

Administration Routes

Ondansetron can be administered via:

• Intravenous (IV) route: resulted in the largest improvements in nausea scores 5
• Intramuscular (IM) route: resulted in significant improvements in nausea scores, but less than IV administration 5
• Oral dissolving tablet (ODT) route: resulted in significant improvements in nausea scores, but less than IV administration 5