[The effect of renal replacement therapy on the plasma concentration of antituberculosis drugs].

Objective: To explore the effect of renal replacement therapy (RRT) on the plasma drug concentration of first-line antituberculosis drugs.

Methods: Thirty patients treated with continuous RRT and who were complicated with pulmonary tuberculosis from 2009 September to 2013 September were enrolled in the study. There were 19 males and 11 females, aged 18-75 years. They received RRT 3 times a week, 4 h each. The patients took isoniazid 300 mg and rifampin 450 mg one time every day, and pyrazinamide 40 mg · kg(-1) · d (-1) one time 24 h before RRT, 3 times every week. The plasma concentration of the drugs were monitored before and after each RRT for 4 weeks.

Results: Taken before RRT, the plasma concentration of isoniazid before RRP was (1.62 ± 0.44), (1.67 ± 0.38), (1.63 ± 0.41), (1.48 ± 0.38) mg/L respectively for 1-4 weeks; while that after RRT was (0.57 ± 0.22), (0.60 ± 0.24), (0.56 ± 0.20), (0.56 ± 0.15) mg/L (all P < 0.05). Taken before RRT, the plasma concentration of pyrazinamide before RRT was (16.08 ± 4.95), (16.32 ± 5.73), (14.89 ± 4.53), (13.81 ± 5.83) mg/L respectively for 1-4 weeks, while that after RRT was (3.73 ± 1.57), (3.57 ± 1.53), (3.22 ± 1.00), (2.81 ± 1.34) mg/L (all P < 0.05). Taken after RRT at once, the plasma concentration of pyrazinamide before RRT was (15.57 ± 3.47), (14.10 ± 2.27), (14.73 ± 2.36), (15.9 ± 3.02) mg/L respectively for 1-4 weeks, while that after RRT was (2.45 ± 1.14), (2.19 ± 1.07), (1.87 ± 1.52), (2.33 ± 1.30)mg/L. Taken before RRT, the plasma concentration of rifampin was (3.44 ± 1.17), (3.72 ± 1.24), (3.68 ± 1.16), (3.44 ± 1.22) mg/L respectively for 1-4 weeks (all P < 0.05), while that after RRT was (2.96 ± 1.10), (3.28 ± 1.04), (3.17 ± 1.02), (2.96 ± 1.05) mg/L (all P > 0.05).

Conclusions: Continuous RRT has different effects on the plasma drug concentration of isoniazid and pyrazinamide. It almost has no effect on rifampin. To achieve the best plasma concentration and better anti-tuberculosis results, isoniazid and pyrazinamide should be taken after RRT, but rifampin before RRT.