The Use of Second Line Drugs in Patients with Drug Resistance to Standard Tuberculostatics

¹ Chair and Department of Tuberculosis and Respiratory Diseases, Postgraduate Medical School

Many patients with far-advanced cavitary pulmonary tuberculosis who had previous inadequate chemotherapy, harbor bacilli resistant to the standard drugs. Approximately 70 per cent of them harbor bacillimainly resistant to two drugs, INH and SM. Proper choice of second line drug regimens should be based on detailed bacteriologic examination and sensitivity tests. Treatment should be started with a threedrug combination given in adequate dosage. The most often used combination given is ethionamide plus pyrazynamide plus cycloserine.

After sputum conversion is achieved, a two-drug combination: ETA plus CS, or ETA plus PZA, is administered. Treatment should be started under institutional conditions and later continued on an ambulatory basis for one and one-half to two years, provided that the patient cooperates fully in his treatment. In our study, when these principles were followed, 92.4 per cent of sputum conversions were obtained after one year of treatment and 100 per cent of sputum conversion after one and one-half to two years of treatment. Among 25 patients who completed treatment of one and one-half year or longer, there were no relapses in the period of one to three years after drugs were discontinued.

Unfortunately, about 35 per cent of patients stop their treatment due to side effects of the drugs or because they refuse treatment. In our overall study, about 65 per cent of patients were lost to treatment due to various reasons, the majority of them within the first year of treatment.