Background and purpose: Many studies have been done to determine the distribution of acetylator phenotypes among populations of different geographic origin. The goal of this study was to investigate the acetylator phenotypes of the Iranian population and compare them between tubercular patients and healthy subjects.
Methods: The study population consisted of two groups; the first group included 100 newly diagnosed tubercular patients and the second group consisted of 100 healthy subjects. Acetylator phenotype was determined from the metabolic ratio of acetyl-isoniazid to isoniazid in the plasma samples. Metabolic ratio was used to classify subjects as slow (= or < 0.70) or fast acetylators (>0.70).
Results: In the tubercular patients, the frequencies of slow and fast acetylator phenotypes were 62 and 38%, respectively. Of the healthy individuals, 45% were found to be slow acetylators and the remaining 55% were fast acetylators.
Conclusion: It seems that tubercular patients metabolize isoniazid more slowly than healthy individuals.