NAT2 genotype-guided treatment with stratified isoniazid dose (approx. 7.5 mg/kg b.w., patients homozygous for NAT2*4: rapid acetylators; 5 mg/kg, patients heterozygous for NAT2*4: intermediate acetylators; 2.5 mg/kg, patientes without NAT2*4: slow acetylators)

Treatment with conventional standard isoniazid dose (approx. 5 mg/kg b.w.)

Modified daily isoniazid dose : approx. 7.5 mg/kg, 5 mg/kg and 2.5 mg/kg for rapid, intermediate and slow acetylators, respectively

1) the incidences of drug-induced liver injury associated with INH that occurred within 8 weeks of the treatments, and 2) the incidence of early treatment failure as indicated by a persistent positive culture or no improvement in chest radiographs at the 8th week