Importance of rifampicin in combined daily/intermittent chemotherapy for tuberculosis

Three different partly intermittent regimens were evaluated in order to assess the value of rifampicin (RMP) in the continuation phase of treatment for tuberculosis. Patients suffering from newly diagnosed culture-positive pulmonary tuberculosis were admitted to the trial. All were initially treated daily for 8 weeks with a quadruple combination including RMP. The intensive treatment phase was followed by twice-weekly intermittent treatment for 16 weeks with one of three different combinations, one containing RMP. Of 246 patients, 85 were withdrawn, 7 because of adverse events. At the end of treatment 127 of 135 patients (94,1%) from whom sputum results could be obtained, had negative sputum cultures, and 6 had one colony growth. Of 42 patients who had one or more positive sputum cultures during follow-up of 96 weeks, 6 belonged to the RMP group compared with 20 and 16 of the other groups (P = 0,0244). The results indicate that a combined daily/intermittent regimen containing RMP in both phases can be safely used, whereas a similar regimen with the same duration but not including RMP in the continuation phase, is inferior.