Salivary antipyrine half‐life: a useful measure of hepatic drug metabolism [letter].

The rate of disappearance of antipyrine from plasma after a single oral dose is a useful indicator in man of the drug metabolising capacity of the liver (Vessell & Page, 1968). With the proliferation of new drugs and the increasing effect of these agents on bodily functions, newer methods of examining the drug metabolising capacity of man have been discovered, such as the urinary excretion of D-Glucaric acid and plasma glutamyl transpeptidase activity (Davidson, McIntosh & Ford, 1974). However, despite these new methods, measurement of plasma antipyrine half-lives remains a reliable method for assessing hepatic drug metabolism.