Effect of preanaesthetic medication on anaesthesia with ICI 35, 868.

The effect of three commonly used premedicants and a control on anaesthesia with ICI 35, 868 is described. Two randomized studies were performed--one a group study of induction characteristics at 2 mg kg-1 and the other a detailed study in patients undergoing minor gynaecological surgery with an induction dose of 1.5 mg kg-1 and maintenance with incremental doses plus 66% nitrous oxide in oxygen. Premedication had little effect on the already good induction characteristics. Only heavy opiate premedication produced reliable induction at 1.5 mg kg-1, but with an increase in side-effects. Diazepam appears to be the premedicant of choice, although the overall frequency of pain on injection has not been affected by premedication.