From the Guidelines
Ondansetron (Zofran) in combination with dexamethasone is the most effective anti-emetic regimen for post-surgical nausea, as recommended by the latest guidelines 1. The typical adult dose of ondansetron is 4mg IV or 8mg orally, which can be repeated every 8 hours as needed. Dexamethasone, at a low dose of 4mg IV, is a good additive preventative agent and facilitates hepatic regeneration 1. This multimodal approach is supported by the international consensus group on PONV, which recommends using at least 2 antiemetic drugs to decrease PONV and improve efficacy 1.
Key Considerations
- The use of 5-HT3 antagonists, such as ondansetron, is recommended as the primary treatment due to their safe side effect profile 1.
- Low-dose dexamethasone is a good additive preventative agent, but it should be used with caution in diabetics as it can transiently worsen glycemic control [(1, 2)].
- A multimodal approach to postoperative nausea and vomiting should be used, including the use of at least 2 antiemetic drugs 1.
- Alternative options, such as promethazine (12.5-25mg IV/IM), can be used for patients who don't respond to ondansetron 3.
- Scopolamine patches can be applied before surgery for longer-lasting prevention 3.
Patient-Specific Considerations
- Patients with risk factors, such as female gender, non-smoking status, history of motion sickness, or previous post-operative nausea, may benefit from a multimodal approach combining different anti-emetics [(3, 1)].
- Adequate hydration and early mobilization after surgery can also help reduce nausea symptoms 3.
From the FDA Drug Label
Ondansetron Injection is indicated for the prevention of postoperative nausea and/or vomiting. As with other antiemetics, routine prophylaxis is not recommended for patients in whom there is little expectation that nausea and/or vomiting will occur postoperatively In patients in whom nausea and/or vomiting must be avoided postoperatively, Ondansetron Injection is recommended even when the incidence of postoperative nausea and/or vomiting is low.
The best anti-emetic for post-surgical nausea is ondansetron (IV), as it is specifically indicated for the prevention of postoperative nausea and/or vomiting.
- Key benefits of ondansetron include: + Prevention of postoperative nausea and/or vomiting + Effective in patients undergoing various types of surgery, including outpatient procedures and major abdominal or gynecological surgeries + Approved for patients aged 1 month and older
- Dosage: a single 4-mg intravenous dose is recommended for adults, while pediatric patients receive 0.1 mg/kg for those weighing 40 kg or less, or 4 mg for those weighing more than 40 kg 4, 5.
From the Research
Postoperative Nausea and Vomiting Treatment
- The most effective anti-emetic for post-surgical nausea is a topic of ongoing research, with several studies comparing the efficacy of different medications 6, 7, 8, 9, 10.
- Ondansetron, a 5-HT3 receptor antagonist, has been shown to be effective in reducing postoperative nausea and vomiting in several studies 6, 7, 9, 10.
- A study published in 1994 found that ondansetron 4 mg was the optimal dose for treating postoperative nausea and vomiting 6.
- Another study published in 1991 found that ondansetron 8 mg was effective in 78% of patients, compared to 28% for placebo 7.
- A meta-analysis published in 2016 compared the efficacy of ondansetron and dexamethasone for prophylaxis of postoperative nausea and vomiting in patients undergoing laparoscopic surgeries, and found that dexamethasone was superior to ondansetron in preventing postoperative nausea after 4-6 hours 8.
- A study published in 1996 found that the combination of ondansetron and dexamethasone was effective in preventing postoperative nausea and vomiting, and that this combination was more effective than either medication alone 10.
Comparison of Anti-Emetic Medications
- Ondansetron and dexamethasone are both effective anti-emetic medications, but they have different mechanisms of action and side effect profiles 8, 9, 10.
- A study published in 2006 found that 5-HT3 receptor antagonists, such as ondansetron, are effective in preventing postoperative nausea and vomiting, and that they can be used in combination with other medications, such as dexamethasone, for enhanced efficacy 9.
- The choice of anti-emetic medication will depend on the individual patient's needs and medical history, as well as the specific surgical procedure being performed 6, 7, 8, 9, 10.