What are the medications for nausea (antiemetics)?

From the Guidelines

For nausea, I recommend starting with ondansetron (Zofran) 4-8 mg taken orally every 8 hours as needed. This is based on the most recent and highest quality study available, which suggests that ondansetron is an effective and well-tolerated option for managing nausea 1. For severe nausea, promethazine (Phenergan) 12.5-25 mg every 6 hours or metoclopramide (Reglan) 10 mg three times daily are effective alternatives. Non-prescription options include ginger supplements (250 mg four times daily) or Dramamine (dimenhydrinate) 50-100 mg every 4-6 hours. These medications work through different mechanisms: ondansetron blocks serotonin receptors in the brain and gut, promethazine blocks histamine receptors, metoclopramide improves stomach emptying, and ginger has natural anti-nausea properties.

Some key points to consider when managing nausea include:

• Identifying and treating underlying causes of nausea, such as constipation, CNS pathology, chemotherapy, radiation therapy, or hypercalcemia 1
• Using a combination of antiemetic agents that target different mechanisms of action to achieve a synergistic effect 1
• Considering the use of corticosteroids, such as dexamethasone, which have been shown to be effective in reducing nausea and vomiting 1
• Being aware of the potential side effects of antiemetic medications, such as drowsiness, and advising patients to avoid driving or operating heavy machinery if necessary

It's also important to note that if nausea persists for longer than a week, the cause of nausea needs to be reassessed and opioid rotation must be considered 1. Additionally, for persistent nausea lasting more than 48 hours, especially if accompanied by severe vomiting, dehydration, or abdominal pain, seek medical attention as this could indicate a more serious condition requiring evaluation.

From the FDA Drug Label

In a double-blind US trial in 336 patients receiving a cyclophosphamide-based chemotherapy regimen containing either methotrexate or doxorubicin, ondansetron tablets 8 mg administered twice a day, was as effective as ondansetron tablets 8 mg administered 3 times a day in preventing nausea and vomiting Ondansetron tablets were significantly more effective than placebo in preventing vomiting Treatment response was based on the total number of emetic episodes over the 3-day trial period.

Ondansetron is effective in preventing nausea and vomiting.

• The recommended dosage is 8 mg administered twice a day.
• It is significantly more effective than placebo in preventing vomiting. 2

From the Research

Nausea Medications

• The most frequently prescribed medications for nausea in the emergency department include droperidol, promethazine, prochlorperazine, metoclopramide, and ondansetron 3.
• Ondansetron is as effective as promethazine and is not associated with sedation or akathisia, making it a potential first-line agent for relief of nausea or vomiting in most patient populations 3.
• A study comparing ondansetron and metoclopramide with placebo for adults with undifferentiated emergency department nausea and vomiting found similar reductions in nausea severity for all three groups 4.
• Dimenhydrinate and metoclopramide have similar efficacy in reducing nausea and vertigo symptoms in the emergency department 5.
• The combination of ondansetron and dexamethason is effective in preventing postoperative nausea and vomiting in patients undergoing laparoscopic cholecystectomy 6.

Comparison of Antiemetic Agents

• Ondansetron and metoclopramide are effective antiemetic agents, but ondansetron has a better safety profile 3, 4.
• Metoclopramide and dimenhydrinate have similar efficacy in treating nausea and vertigo 5.
• The choice of antiemetic agent depends on the individual patient's needs and medical history 3, 4, 5, 6.

Treatment of Nausea and Vomiting

• Antiemetic therapy is often required to manage nausea and vomiting in patients, especially in the emergency department and postoperative settings 3, 7, 4, 5, 6.
• The goal of treatment is to relieve symptoms and prevent morbidity 7.
• Treatment options include medication, such as ondansetron, metoclopramide, and dimenhydrinate, as well as other interventions like intravenous rehydration 3, 7, 4, 5, 6.