Is there an increased risk of TB relapse in patients treated with fixed-dose combination drugs in Indonesia?

South Sulawesi Province, Republic of Indonesia.

To compare relapse rates among tuberculosis (TB) patients treated with fixed-dose combination drugs (FDCs) and patients treated with the same regimen using loose drugs.

Between 1999 and 2001, new smear-positive TB patients were randomly allocated to treatment with four-drug FDCs or loose drugs to study differences in treatment outcomes. Although it was not in the original study design, in 2004-2005 we performed a follow-up study by home visit of cured patients. We conducted an interview and tried to collect a sputum sample from each patient. If the patient was absent or had died, a proxy interview was conducted. The sputum samples were examined by microscopy and culture.

The overall relapse rate was 7.0% in patients who were able to produce a sputum sample. Relapse appeared to be more frequent in the FDC group compared to the loose drug group (10.1% vs. 2.7%, P = 0.074).

This is the first documented long-term follow-up study of patients treated with four-drug FDCs. There is an indication that treatment of new sputum smear-positive TB patients with FDCs provides an increased risk of relapse compared to treatment with loose drugs. The long-term results of treatment with FDCs should be carefully evaluated in other settings.