Pharmacokinetics of First-Line Anti-Tubercular Drugs

Determining the optimal dosages of isoniazid, rifampicin, pyrazinamide and ethambutol in children is necessary to obtain therapeutic serum concentrations of these drugs. Revised dosages have improved the exposure of 1st line anti-tubercular drugs to some extent; there is still scope for modification of the dosages to achieve exposures which can lead to favourable outcome of the disease. High dose of rifampicin is being investigated in clinical trials in adults with some benefit; studies are required in children. Inter-individual pharmacokinetic variability and the effect of age, nutritional status, Human immunodeficiency virus (HIV) infection, acetylator genotype may need to be accounted for in striving for the dosages best suited for an individual.