Transdermal hyoscine and postoperative nausea and vomiting.

Forty-two patients, undergoing major gynaecological surgery, were randomly allocated to have a patch applied to the skin behind one ear, containing either hyoscine or placebo. They were followed up at 24-hour intervals for 3 days postoperatively and divided into matched pairs for statistical analysis. There was a significant (p less than 0.01) reduction in nausea and vomiting in the first 24 hours postoperatively, but no difference thereafter. There was an increased incidence of visual disturbance in the hyoscine group at 48 hours, but no other differences in the side effects studied at any other time. However, despite receiving hyoscine there was still a high incidence (68%) of severe nausea and vomiting.