COMPARISON OF THE EFFECTS OF ISOFLURANE OR FENTANYL-NITROUS OXIDE ANAESTHESIA ON PROPRANOLOL DISPOSITION IN DOGS

The disposition of propranolol was studied, using dual-route administration, in two groups of six dogs. Each dog was studied on three consecutive days: day 1 awake, day 2 during anaesthesia, and day 3, 24 h after anaesthesia. Anaesthesia was with isoflurane 2.0 MAC (in oxygen) in one group and with a fentanyl—nitrous oxide—atracurium regimen in the other group. In the group receiving fentanyl, anaesthesia caused a significant decrease (63%) in intrinsic clearance from the day 1 value (P