Comparison of sputum conversion time in tuberculosis treatment with fix-dose combination drugs and separate drug regimens

During tuberculosis (TB) treatment, the period of transmission will shorten and disease will be better controlled in the society if the drugs be more potent and the sputum conversion time from positive to negative be less. There are two drug regimens in the treatment of TB: fixed-dose combination drugs and separate-dose drugs. Our aim in the study was comparing the sputum conversion time pattern in TB smear-positive patients treated with the aforementioned regimens. This randomized clinical trial was done on 331 patients with smear-positive TB. Randomization was based on random numbers table. Intervention group was treated with fixed-dose combination, and nonintervention group was treated with separate drugs. Smear conversion time pattern at the end of second, third, fourth, and sixth months after beginning of the treatment was compared and analyzed by extended Cox regression test. Sputum smear conversion rate in the intervention and control group at the end of second, third, and fourth months of treatment was 70.23 versus 76.47%, 54 versus 67.24%, and 33.33 versus 68.75%, respectively (P>0.05). Variables such as smoking, drug addiction, and sputum bacillary load were effective on smear conversion time in two study groups. The study results showed no difference in efficacy of two-drug regimens in conversion time of sputum smears to negative in TB smear-positive patients.