THE RATE OF DISAPPEARANCE OF THIOPENTAL FROM THE PLASMA IN THE DOG AND IN MAN

¹ Departments of Metabolism, Experimental Surgery, and Biochemistry, Army Medical Service Graduate School, Walter Reed Army Medical Center, Washington 12, D. C.

The plasma levels of thiopental after intravenous injection were measured in a series of dogs and of patients. A three term exponential equation was derived to describe the plasma level as a function of time after injection. In the dogs thiopental was taken up relatively slowly in the body fat to a fat to plasma concentration ratio of approximately 8:1.

Comparison of the usual rates of administration of thiopental with the observed rates of disappearance from the plasma indicate that uptake of the drug by fat is probably of minor importance in clinical anesthesia.