What do systematic reviews say?

Opioid antagonists vs placebo

Opioid antagonists showed no clear difference in vomiting ‐ postoperative compared with placebo (low certainty).

• Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section 2021 · Cochrane Headline outcomes only
  RR 1.25 [0.35, 4.43]
  1 study · 120 participants
  Low