From the Research
Ondansetron is generally considered more effective than metoclopramide for treating vomiting caused by Nubain (nalbuphine). For adults experiencing opioid-induced nausea and vomiting from nalbuphine, ondansetron 4-8 mg IV or orally every 8 hours as needed is recommended. Ondansetron works by blocking serotonin 5-HT3 receptors in the chemoreceptor trigger zone and gastrointestinal tract, directly targeting the mechanism of opioid-induced nausea and vomiting. Metoclopramide, while effective for some types of nausea, has more side effects including extrapyramidal symptoms and may be less effective specifically for opioid-induced vomiting. Additionally, ondansetron has fewer central nervous system effects compared to metoclopramide, making it particularly advantageous when combined with opioids like nalbuphine which already affect the central nervous system. If ondansetron is unavailable, metoclopramide 10 mg IV or orally every 6 hours can be used as an alternative, but with closer monitoring for side effects.
Some key points to consider:
- The most recent and highest quality study 1 compared the efficacy of ondansetron and metoclopramide with placebo for adults with undifferentiated emergency department nausea and vomiting, and found that reductions in nausea severity were similar for 4 mg intravenous ondansetron, 20 mg intravenous metoclopramide, and placebo.
- Another study 2 found that ondansetron was not superior to metoclopramide and promethazine in reducing nausea in ED adults.
- However, a study from 1990 3 found that ondansetron was more effective than metoclopramide in the prophylaxis of nausea and vomiting induced by chemotherapy.
- The study from 2010 4 recommended ondansetron as a first-line agent for relief of nausea or vomiting for most patient populations in the ED due to its safety and efficacy.
Overall, while the evidence is not entirely consistent, ondansetron is generally considered a better option than metoclopramide for treating vomiting caused by Nubain (nalbuphine) due to its efficacy, safety, and fewer side effects.