The effect of premedication on the induction dose of propofol in dogs and cats.

The effect of premedication on the induction dose of propofol was determined in 15 cats and 25 dogs undergoing elective surgical procedures. The induction dose of propofol in dogs younger than 8 years old was 6.9 +/- 0.9 mg kg-1 (n = 4) without premedication and 4.3 +/- 1.4 mg kg-1 (n = 12) with premedication with acetylpromazine maleate. The induction dose in cats younger than 3 years old was 7.8 +/- 1.1 mg kg-1 (n = 8) with atropine alone and 7.1 +/- 0.9 mg kg-1 (n = 7) with the inclusion of acetylpromazine maleate. The reduction in the induction dose of propofol was statistically significant in dogs, but not in cats. When atropine was used together with a fentanyl-droperidol combination or pethidine and acetylpromazine maleate in dogs, the mean induction dose of propofol was reduced to 2.1 +/- 0.1 mg kg-1 (n = 4) and 2.4 +/- 0.3 mg kg-1 (n = 5), respectively. Propofol was also evaluated as an induction agent in patients undergoing non-elective surgical procedures.