Abstract

Introduction: We aimed to investigate the in vitro efficacy of fusidic acid (FA) on tuberculosis strains resistant to antituberculous drugs .

Material and Method: In our single center, prospective, randomized controlled study, we researched the efficacy of sodium fucidate on tuberculosis bacilli at dosages of 128-64-32- 16 mg/l, carried out on Lowenstein Jensen solid media using absolute concentration method. Between March 2000 and February 2001, sputum cultures of 728 tuberculosis patients were tested for drug susceptibility against 4 major antituberculous drugs [isoniazid (H), rifampin (R), ethambutol (E), streptomycin (S)] including fusidic acid (FA). Firstly, the study was designed to determine drug susceptibility at 32-64-128 mg/l for fusidic acid. Out of 728 cultures 488 cultures were tested for these concentrations for fusidic acid and to 4 major drugs. Following this, additional 240 cultures were tested for 16mg/l concentration of fusidic acid and to major drugs.

Results: Drug susceptibility testing showed no resistance to the sodium fucidate at the dosages of 128-64-32 mg/l on 488 cultures. Resistance to R,H,S,and E were 10.4%, 8.19%, 5.32%, and 0.6% respectively. At 16 mg/l dosage the resistance to sodium fucidate was determined on 10 cultures (4.16%). Multi drug resistance rate was 7.5% among 728 cultures. There was sodium fucidate resistance in only one of the 55 multi drug resistant tuberculosis (MDR-TB) strains.

Conclusion: We determined that sodium fucidate has a powerful in vitro efficacy at dosages of 32 mg/l and over. It was also effective at dosage of 16 mg/l, but resistance was observed at this concentration. Fusidic acid could be an alternative drug for multidrug or extensively drug resistant cases. (Tur Toraks Der 2008;9:109-12)