Treatment of cutaneous leishmaniasis with a sequential scheme of pentamidine and tamoxifen in an area with a predominance of Leishmania (Viannia) guyanensis: A randomised, non‐inferiority clinical trial

Objective To determine whether a combination of a single intramuscular (IM) dose of pentamidine (7 mg/kg) followed by oral tamoxifen 40 mg/day for 20 days is non‐inferior to three IM doses of pentamidine 7 mg/kg in the treatment of cutaneous leishmaniasis with a margin of 15%. Methods Phase II, randomised, controlled, open‐label, non‐inferiority clinical trial. Primary outcome was the complete healing of the lesions 6 months after starting treatment. Secondary outcomes were healing 3 months after starting treatment and determining the presence and severity of adverse effects (AE). Results The research was concluded with 49 patients; Leishmania (Viannia) guyanensis was the most frequent species isolated. In the primary outcome, 18 (72%) (95% CI: 52.4%–85.7%) of the 25 patients allocated to the intervention group and 24 (100%) (95% CI: 86.2%–100%) of the control group (p = 0.015) met the established criteria of cure. There was no AE with tamoxifen. Conclusion Although a 72% cure rate presented by the combination of tamoxifen and pentamidine was lower than in the control group that achieved a 100% cure, it is still a safe and is a clinically relevant result. It indicates that the therapeutic scheme evaluated may be a promising option for populations in remote areas, however it should be further studied, in order to include a larger number of patients.