The effect of isoniazid containing regimen on CYP2E1 during antituberculosis therapy.

Because isoniazid is a selective inducer of CYP2E1 and isoniazid-induced hepatotoxicity is believed to be due to activation of its metabolites by CYP450, this study was undertaken to determine the effect of isoniazid containing regimen on CYP2E1 in TB-patients. The activity of CYP2E1 in 11 newly diagnosed TB-patients (5 F, 6 M) was investigated before (day 0) and during (day 14) treatment for tuberculosis. CYP2E1 activity was measured using the plasma metabolic ratio (MR) of 6-hydroxy-chlorzoxazone to chlorzoxazone, while CYP2E1 quantity in the peripheral lymphocytes was measured using SDS-PAGE.

The CYP2D6 gene locus in South African Coloureds: unique allele distributions, novel alleles and gene arrangements.

Objective: The highly polymorphic CYP2D6 gene locus has been extensively scrutinised in the major ethnic populations, but little is known about the locus for many indigenous and unique admixed populations, including the Coloureds of South Africa. This study aimed at characterising the CYP2D6 gene locus in Coloured subjects and predict their phenotype status.

Methods: CYP2D6 genotyping was performed on 99 Coloured subjects by long-range polymerase chain reaction (PCR) and PCR restriction fragment length polymorphism (RFLP).