This controlled clinical study was carried out to investigate the possibility of reducing the duration of chemotherapy by using rifampicin combined with other drugs and also to see if there could be no relapse even if the duration of follow-up was prolonged.
In the first study, initiated on May 1974, two different duration of the regimen rifampicin-isoniazid-ethambutol-12 months (A) and 18 months (B) allocated at random was studied. The criteria to the study: Patients should be admitted to our hospital, have pulmonary tuberculosis with at least one cavity and sputum smear positive, previously untreated or treated less than 15 days.
A total of 219 patients were enrolled into the study, 100 in group A, 119 in group B. But after reducing the unsuitable patients who did not meet the protocol requirements, 86 (A) and 92 (B) have remained for the final analysis.
The background factors were almost the same in each group (Table 1). All cases converted within 4 months (Fig. 1) More than one third of the cavities remained open when the treatment was completed (Table 2). Adverse reactions were seen in 16% among the total of 219 cases. Especially the liver dysfunction was seen in 4 patients (2%).
It has now elapsed 9 (A) and 8.5 years (B) after stopping the chemotherapy. Owing to the progressing lack of communications with the patients as the time elapsed, we could not make a through investigation (Fig. 2). Although there was no relapse until 24 months, one relapsed bacillary in the 28th month (B), of whose cavitary lobe had been resected following to the sputum conversion and the resected specimens were all culture negative.
In group A, 3 cases relapsed (2 bacillary and 1 only radiological): one in the 59th month, the second in the 66th month who was an uncontrolled diabetic and relapses occurred 2 times and the third, radiologically relapsed, in the 33th month who was also diabetic (Table 4).
The bacilli of these 3 patients were sensitive as they were before and the patients were treated effectively with the same regimen (Table 5). If we confine the duration of follow-up to the period of 24 months, there was no relapsed case in each group but when the duration of follow up was prolonged, even with 18 month treatment of the regimen-rifampicin-isoniazid-ethambutol, we could not prevent from the relapses perfectory.
