Background. Optimal drug levels and minimal toxicity are critical factors in improving treatment outcomes for patients prescribed new and repurposed medicine for drug-resistant (DR) tuberculosis (TB). The optimal dose and dose-related safety of clofazimine (CFZ), a repurposed medicine for DR TB, in the South African (SA) population are unknown.Objectives. To report on dose-related adverse events in patients receiving CFZ plus a background regimen for DR TB.Methods. In a retrospective review of patient folders from 2012 to 2014, adverse events documented for patients receiving high- (≥200 mg) and low-dose (100 mg) CFZ in a centralised DR TB hospital in KwaZulu-Natal Province, SA, were investigated for an association between dose-weight interactions and adverse events.Results. Of 600 patients included, 78.7% (n=472) weighed ≥50 kg. Of these, 17.4% (n=82) received 100 mg CFZ and 82.6% (n=390) received >200 mg. Of 128 patients (21.3%) who weighed Conclusions. There is an association between dose-weight interaction and adverse events. The odds of any adverse event occurring were higher when low-weight patients (