Slide 24 Slide showing extra absorption of salicylamide at higher doses. (redrawn from Barr, W.H. Drug Info. Bull., p27, 1969). Normally the amount of drug present in the body is no more than the enzymes can handle easily. Metabolism then proceeds in apparent first order fashion. However for some drugs the enzymes can not keep up. Illustrated here is one example, saturation of first pass metabolism allowing more or a higher fraction of drug to be absorbed.

Copyright 2001 David W.A. Bourne