Nifurtimox (NFX) is one of the approved drugs used to treat Chagas disease. Safety profile studies and
models on risk factors for treatment interruption in adults are scarce in Latin America. This study evaluated retrospectively
the medical records of adult Chagas disease patients treated with NFX between 2007 and 2012 in Bogotá, Colombia.
An accelerated failure time model was used, and associations were expressed as time ratio (TR). In total, 76 adult patients
with NFX were included: 60 (79.0%) completed 60 days of treatment, 61 (80.3%) presented adverse drug reactions
(ADRs), and 16 (21.0%) required treatment interruption. The predominant symptoms were epigastric pain (23.7%),
nauseas (18.4%), sleep disturbances (18.4%), loss of appetite (17.1%), and temporary loss of memory (15.2%). ADRs
were classified as mild (64.5%), moderate (30.4%), and severe (5.1%). Time of treatment was significantly longer when
presenting ≤ 3 ADRs (TR: 1.78; 95% CI: 1.04–3.03), presence of non-severe ADRs (TR: 6.52; 95% CI: 3.24–13.1),
doses of NFX ≤ 8 mg/kg/day (TR: 1.78; 95% CI: 0.90–3.49), and age < 48 years (TR: 1.57; 95% CI: 0.90–2.74). Treatment
with NFX in adults caused a high frequency of ADRs, but most of the cases were mild and did not require treatment
interruption. Severity and number of ADRs were the main predictors for treatment interruption.