Correlation between thiopental induction dose and the volume of distribution of caffeine in human subjects.
The correlation between the apparent volume of distribution (aVd) of caffeine and the induction dose of thiopental was studied in 23 patients. Caffeine, which has an effective partition coefficient that approaches that of thiopental, was used as an indicator substance to estimate the immediate volume of distribution of thiopental. The immediate volume of distribution is critical in determining thiopental induction dose. The aVd of caffeine was determined noninvasively from serial saliva samples after consumption of caffeine, which was given to the patients as coffee. A strong correlation (r = .69; P less than .01) was found between the aVd of caffeine and the anesthetic induction dose of thiopental when the loss of eyelid reflex was used as the end point. The correlation between thiopental induction dose and body weight for the same individuals (r = .188) was not statistically significant.
D000328:Adult; D001767:Blinking / Q000187:drug effects; D002110:Caffeine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D013246:Sterilization, Tubal; D013874:Thiopental / Q000008:administration & dosage / Q000494:pharmacology*
D002110:Caffeine; D013874:Thiopental