Canadian Journal of Anesthesia, Vol 23, 170-175, Copyright © 1976 by Canadian Anesthesiologists' Society

The Reduction of Coma Time in Lipophilic Drug Overdose Using Castor Oil

¹ Departments of Anaesthesia and Clinical Biochemistry, University of Western Ontario, Victoria Hospital, London, Ontario

A clinical trial of castor oil in overdoses of lipophilic drugs gave a strong clinical impression that it was effective in speeding up recovery. Therefore, animal experiments were undertaken to confirm that castor oil acts as a ligand in Ethchlorvynol poisoning and that its use reduces coma time.

Serial serum levels of Ethchlorvynol were obtained from dogs given Ethchlorvynol 150 mg/kg alone, and the same dose dissolved in castor oil 15 ml/kg in a crossover fashion. The result was a reduction of peak serum levels and of the halflife of the drug when the castor oil solution was used.

In order to mimic the clinical situation more closely, a further crossover study was undertaken using Ethchlorvynol 300 mg/kg alone and the same dose followed by castor oil 15 ml/kg repeated q12h. This showed no delay in reaching peak serum concentration and no reduction of peak levels. However, it did show a 31 per cent reduction in the half-life of the drug. This change is statistically significant, and supports the continued use of castor oil in lipophilic drug overdose.