Efficacy and safety of kanamycin, ethionamide, PAS and cycloserine in multidrug-resistant pulmonary tuberculosis patients.

Background: We carried out this study to determine the efficacy and safety of a regimen containing kanamycin, ethionamide, isoniazid, para-aminosalicylic acid (PAS) and cycloserine in the treatment of multidrug-resistant tuberculosis (MDR-TB).

Methods: A prospective, uncontrolled study of 39 pulmonary tuberculosis patients, who had received adequate first-line antituberculosis treatment including supervised category II retreatment regimen, and were still sputum smear positive for acid-fast bacilli (AFB) in whom sputum culture revealed isolates of M. tuberculosis resistant to rifampicin and isoniazid with and without resistance to other antituberculosis drugs. They received kanamycin (initial 4-6 months), ethionamide, isoniazid, PAS and cycloserine for a minimum period of two years.

Results: Out of 39 patients, 29 (74.3%) achieved sputum conversion within six months and remained so at the end of two years. Two (5.1%) patients died, six (20.6%) patients were lost to follow up, and two (5.1%) patients remained sputum smear-positive for AFB through out the period of study. Twenty-nine patients, declared cured, were followed for an average period of 16 months (3-48 months), during which two (6.9%) patients relapsed, four (13.8%) patients were lost to follow-up and remaining 23 remained sputum smear-negative. Eight (21.1%) patients developed major side effects which required stoppage/change of drugs.

Conclusions: In MDR-TB patients, regimen consisting of ethionamide, isoniazid, PAS and cycloserine and kanamycin appears to be effective and safe.