For children undergoing tonsillectomy, sex influences opioid-related adverse effects, according to a study published online December 17 in Pain Medicine.

There was no significant difference noted in the overall incidence of respiratory depression between boys and girls, but as the total perioperative morphine dose increased to ?0.3mg/kg, the incidence of respiratory depression and postoperative nausea and vomiting (PONV) tended to be higher in white girls than boys (respiratory depression: 52 vs. 32%; PONV: 43 vs. 4%).