Five year results of a 3-month and two 5-month regimens for the treatment of sputum-positive pulmonary tuberculosis in south India. [Daily ultrashort chemotherapy and intermittent short-term chemotherapy with 4 drugs of communicable pulmonary tuberculosis treated for the first time. Results of a cooperative multicenter study]. Treatment of pulmonary tuberculosis with short course chemotherapy in south India--5-year follow up. Shortest possible acceptable, effective ambulatory chemotherapy in pulmonary tuberculosis: preliminary report I. A controlled trial of 3-month, 4-month, and 6-month regimens of chemotherapy for sputum-smear-negative pulmonary tuberculosis. Results at 5 years. Hong Kong Chest Service/Tuberculosis Research Centre, Madras/British Medical Research Council.
A controlled study of three short-course regimens was undertaken in South Indian patients with newly diagnosed, sputum-positive pulmonary tuberculosis. The patients were allocated at random to one of three regimens: a) Rifampicin, streptomycin, isoniazid and pyrazinamide daily for 3 months (R3); b) the same regimen as above but followed by streptomycin, isoniazid and pyrazinamide twice-weekly for a further period of 2 months (R5); c) the same as R5 but without rifampicin (Z5). A bacteriological relapse requiring treatment occurred by 5 years in 16.8% of 113 R3, 5.2% of 97 R5, and 20.0% of 115 Z5 patients with organisms sensitive to streptomycin and isoniazid initially. The differences in the relapse rates between the R3 and R5 regimens and the R5 and Z5 regimens were statistically significant (p less than 0.01 for both). Considering patients with organisms initially resistant to streptomycin or isoniazid or both, 7 of 52 patients (4 R3, 2 R5, 1 Z5) had a bacteriological relapse requiring retreatment. Three short-course regimens, all comprising isoniazide (H), rifampicine (R), streptomycine (S) and pyrazinamide (Z), are compared in a randomized prospective cooperative clinical trial. The drugs are given daily in a 3-month regimen (3-HRSZ), twice a week in a 6-month regimen (6-HRSZ2), and in a further two-phase 6-month regimen the 4 drugs are administered 3 times a week for the first 3 months followed by the administration of HSZ twice a week (without R) for further 3 months (3-HRSZ3/3-HSZ2). The number of patients admitted to study is 80, 144 and 139 respectively. The 3-month regimen has been stopped because of a high rate of relapses. 17 p.c. of the patients admitted have to be excluded from analysis for various reasons, out of these 5.8 p.c. because of adverse reactions. Two thirds of the patients had heavily positive sputum cultures at the start. 300 patients completed therapy. At the end of therapy cultures were negative in 94 p.c., 100 p.c. and 99 p.c. respectively. The rate of bacteriological relapses is 19 p.c. in 3-HRSZ, 9 p.c. in 3-HRSZ3/3-HSZ2 and 3 p.c. in 6-HRSZ2, during a follow-up period of 3-4 years after completing therapy. The acceptability was good in all treatment groups. Adverse reactions like "flu" were rarely observed. Increased blood urea was common but in general without clinical symptoms. Elevation of ALAT and ASAT was relatively frequent but mostly transient and without clinical importance. The results served as basis for the new "Recommendation for Treatment of Tuberculosis" and are interpreted with regard to practical consequences and possibilities for further rationalisation of treatment. A controlled clinical trial of three short-course chemotherapy regimens was undertaken in patients with newly diagnosed bacteriologically positive pulmonary tuberculosis. The patients were randomly allocated to receive one of three regimens: rifampicin, streptomycin, isoniazid and pyrazinamide daily for 2 months, followed by streptomycin, isoniazid and pyrazinamide twice weekly for 3 months (R/5) or for 5 months (R/7), or the same regimen as R/7 but without rifampicin (Z/7). A bacteriological relapse requiring retreatment occurred by 5 years in 7.1% of 126 R/5, 4.0% of 124 R/7 and 6.7% of 253 Z/7 patients with organisms initially sensitive to streptomycin and isoniazid; none of these differences is statistically significant. Of the 31 relapses, 16 occurred within 2 years of the completion of chemotherapy and the remaining 15 between 2 and 5 years. Among 65 patients with initial drug resistance to streptomycin or isoniazid or both, there were six bacteriological relapses requiring retreatment. In two 4.5-month regimens and one 3-month regimen the four most potent antituberculous drugs (isoniazid, rifampin, pyrazinamide, and streptomycin) were given for the initial 3 months of chemotherapy. Acceptance by the patients was high, and bacillary sterilization was achieved in 96% of cases within 2 months. Addition of a fifth drug, ethionamide, during the initial 3 months was neither acceptable nor useful. No relapses were observed during a 12-month follow-up period after completion of the 4.5-month regimens. A relapse rate of 5% followed the 3-month regimen. The toxicity and side effects of antituberculous drugs were observed in 16% of patients during the initial 3-month period. In 3.4% of patients, toxicity necessitated cessation of treatment. In the remaining 13% of patients, adverse side effects could be managed without cessation of treatment. Even when patients were ambulatory and outpatient attendance was required for drug administration, the noncompliance rate was only approximately 10%. With the current over-all cost of drugs being limited to 100 United States dollars, the patients with moderately extensive disease must be treated for 100 days, or a maximum of 100 doses. Of 1,710 Chinese patients with radiologically active pulmonary tuberculosis but with sputum negative for acid-fast bacilli on four or more initial microscopic examinations who were studied for 5 yr, 592 (35%) had one or more initial sputum cultures positive for Mycobacterium tuberculosis. These 592 patients were randomly allocated to receive streptomycin, isoniazid, rifampin, and pyrazinamide daily for 4 months or 3 times a week for either 4 or 6 months. The remaining 1,118 patients with all their initial cultures negative were randomly allocated to receive the same four drugs daily for 3 months or 3 times a week for either 3 or 4 months. There were no bacteriologic failures during chemotherapy, and the relapse rates for the 4-month regimens during the 5 yr were 2% in 293 patients with drug-susceptible cultures initially (95% confidence limits, 1 to 5%); 8% in 59 patients with cultures resistant to isoniazid, streptomycin, or both drugs, but susceptible to rifampin initially; and 4% in 325 patients with all their cultures negative initially (95% confidence limits, 1 to 7%). The combined relapse rate for the 3-month regimens was 7% in 709 patients with all their cultures negative initially (95% confidence limits, 5 to 9%). In Hong Kong, 4 months of chemotherapy is now used routinely in the treatment of patients with smear-negative pulmonary tuberculosis, whether their initial sputum cultures are positive or negative.
Longer periods of treatment (at least up to 6 months) result in higher success rates in patients with active TB, but the differences are small. Under field conditions, where adherence to treatment is a big problem, and shorter regimens might improve adherence, these differences may not be evident. A comparison of <6 months vs. 6 months of treatment under programme conditions would be needed to determine this.