Abstract
Background: Although clofazimine (CFZ) has promising effects against non-tuberculosis mycobacteria pulmonary disease (NTM-PD), the appropriate dosage remains unknown. Objective: To clarify the relationship between CFZ steady-state concentration and its adverse effects and efficacy. Methods: This prospective observational study was conducted among NTM-PD patients who were treated with CFZ (UMIN 000041053). The serum trough concentration of CFZ was quantified with validated high-performance liquid chromatography-mass spectrometry. CFZ-induced pigmentation grade, QTc interval, and negative conversion outcomes were analyzed based on measured CFZ serum concentrations by using t-test, concentration-QTc model, and logistic regression analysis, respectively. Results: Out of the 64 enrolled patients, 35 received a CFZ dosage of 50 mg/day and 29 received 100 mg/day. CFZ concentration was higher in patients with more severe pigmentation than in those with less severe pigmentation (P＜0.001). When the CFZ concentration was 1 mg/L, the QTc interval was estimated to be prolonged to 17.3 (95% confidence interval [CI], 3.9 to 25.4) msec from baseline. Negative conversion was achieved in 33 (51.6%) patients. The steady-state CFZ concentration tends to be high in culture-converted groups of patients with NTM-PD (not significant). Conclusions: The adverse effects and efficacy of CFZ were related to its serum concentration, and therapeutic drug monitoring may enable the maximization of drug efficacy and minimization of its side effects.
一般演題（口演） 4
Findings of a prospective observational study for NTM-PD
