Plasma levels of Rifampicin and Pyrazinamide with pre and post meal administration in tuberculosis patients.

CONTEXT: Various factors affect plasma concentrations of antitubercular drugs in different populations so dosing schedule should be adjusted after therapeutic drug monitoring.

AIMS: To study variability in plasma concentrations of Rifampicin and Pyrazinamide with pre and post-meal administration of drugs in tuberculosis patients.

METHODS AND MATERIAL: 52 patients of pulmonary tuberculosis, divided in to two groups, pre and post-meal through systemic randomization. After taking pre-dose sample, drugs were administered according to the group. Samples were withdrawn at 2, 4, 6, and 10h after drug administration. Analysis of samples was done using HPLC.

RESULTS: Mean±1SD of Cmax of Rifampicin was 7.75±2.82μg/ml, mean±1SD of AUC0-10 was 42.17±17.25μgh/ml, adjusted Tmax was 4.25h. In pre-meal samples, the corresponding values were 7.75±2.88μg/ml, 42.83±18.47μgh/ml, 3.76h and in post-meal samples 8.03±2.30μg/ml, 41.56±16.46μgh/ml and 4.75h. Mean±1SD of Cmax levels of Pyrazinamide was 54.49±21.86μg/ml, mean±1SD of AUC0-10 was 337.94±124.28μgh/ml and adjusted Tmax was 3.49h. In pre-meal samples the corresponding values were 52.00±19.13μg/ml, 329.96±112.11μgh/ml, 3.23h, and in post-meal samples 57.43±23.61μg/ml, 345.58±136.99μgh/ml, 3.54h.

CONCLUSION: There is huge variability in the plasma levels of Rifampicin and Pyrazinamide in population of this sub-himalayan region.