Serum concentrations of rifampin, isoniazid, and intestinal absorption, permeability in patients with multidrug resistant tuberculosis.

This study evaluates the serum concentrations of rifampin (RMP), isoniazid (INH), and intestinal barrier function in patients with multidrug-resistant tuberculosis (MDR-TB), drug susceptible tuberculosis (DS-TB), and health volunteers (HC; controls). Peak serum concentrations of RMP were significantly lower in MDR-TB and DS-TB as compared with HC (odds ratio [OR] = 3.125, confidence interval [CI] [1.037-9.418] and OR = 4.025, CI [1.207-13.418], respectively). The INH peak serum concentration was not significantly different between MDR-TB versus DS-TB or DS-TB versus HC. The percent of mannitol excretion was significantly lower in the MDR-TB group compared with DS-TB (13.18 versus 16.03, analysis of covariance [ANCOVA], P = 0.0369) and compared with HC (13.18 versus 16.61, ANCOVA, P = 0.0291) the other study groups. These data suggested a lower peak serum concentration of RMP for both MDR-TB and DS-TB as compared with the HC group. The data also showed a lower intestinal area of absorption in patients with tuberculosis and even worse in MDR-TB.