Propofol demonstrates antiemetic properties when administered at doses necessary for total intravenous anesthesia and at subhypnotic levels in both adults and children. Besides its direct antiemetic effects, propofol might decrease postoperative nausea and vomiting (PONV) by reducing the required concentration of volatile anesthetic agents.
- 0.5-1.0 mg/kg 15 minutes before the end of surgery. As little as 30 mg has been reported to be as effective as 10 mg of metoclopramide
- Low-dose infusion: 20 mcg/kg/minute IV until the end of surgery
Metoclopramide, while considered a relatively weak antiemetic, is seldom administered as prophylaxis against PONV in adults or children. The efficacy of metoclopramide in preventing PONV remains controversial, with some studies suggesting ineffectiveness. Additionally, meta-analyses comparing antiemetics found ondansetron to be significantly more effective than metoclopramide for PONV prevention. Studies in both adults and children suggest that metoclopramide is effective only at higher doses than typically used, with concerns over increasing risks of adverse effects such as hypotension and extrapyramidal symptoms, particularly in pediatric populations.
- Adults: 10 mg IV
- Children: 0.15 to 0.25 mg/kg IV, maximum 10 mg
| Agent | Adult dose | Timing |
|---|---|---|
| Dexamethasone | 4 mg to 8 mg IV | After induction, because of its slow onset of action |
| Scopolamine (transdermal) | 1.5 mg patch | At least several hours before anesthesia; the evening before or two to four hours prior works equally well |
| Droperidol | 0.625 to 1.25 mg IV | Single dose toward the end of surgery |
| Haloperidol | 1 mg IV, oral, or IM | Single dose toward the end of surgery |
| Amisulpride | 5 mg IV over one to two minutes | At induction of anesthesia, for prevention |
| Dimenhydrinate or diphenhydramine | 1 mg/kg IV | Optimal dosing response and timing remain undetermined |
| Promethazine | 6.25 to 12.5 mg IV, diluted to ≤1 mg/mL and infused over at least 20 minutes | At induction of anesthesia |
| Prochlorperazine | 5 to 10 mg IV | At the end of surgery |
| Propofol (subhypnotic) | 0.5 to 1.0 mg/kg, or a 20 mcg/kg/minute IV infusion | 15 minutes before the end of surgery; infusion run until the end of surgery |
