STUDIES ON ISONIAZID ACETYLATION AND POLYMORPHISIM IN HUMANS

Abstract

Phyenotype frequencies of fast and slow acetylators of the drug isoniaz id (INH) were de termined in 157 subjects including norma l (80) and tuberculosis (7 7) patients selected from twin cities of Rawalp ln Ji and Islamabad. The drug, INH, was administered orally to the subjects. The plasma INH concentration was determined spec t rophotometrically. The results show that INH lS metaboli zed in humans at extremely variable rates. On this basis, two types of phenotypes have been identified: the slow acetylators with less tlilan or equal to (2.5 pg INII/ml), and fast acetylators with more than ( 2. 5 ~g INH/ml). Of the 157 s ubj ects investigated, 50 (31.8 percent) were found to be fast acetylators and 107 (68.2 percent) slow 8cetylators or IN!!. An attempt was made to determine o- relation, if any, between various blood groups and acety lators of INH. The data obtained s how non association be tween blood gro ups and acetylators ( P(0 . 05) . The importance of the findings is discussed with reference to the rational us e of INH in tuberculosis treatment.