An old drug and different ways to treat cutaneous leishmaniasis: intralesional and intramuscular meglumine antimoniate in a reference center, Rio de Janeiro, Brazil.

Background: Treatment of cutaneous leishmaniasis (CL) remains challenging since used drugs are quite toxic, thus contributing to lethality not related to the disease itself but to adverse events (AE). The main objective was to evaluate different treatment regimens with meglumine antimoniate (MA), in a reference centre in Rio de Janeiro, Brazil. Methodology: A historical cohort with 592 patients followed up with physical and laboratory examination was enrolled between 2000 and 2017. The effectivity outcomes were epithelialization and complete healing of cutaneous lesions. AE were graded using a standardized scale. Three groups were evaluated: Standard regimen (SR): intramuscular (IM) MA 10 - 20 mg Sb5+/kg/day during 20 days (n=46); Alternative regimen (AR): IM MA 5 mg Sb5+/kg/day during 30 days (n=456); Intralesional route (IL): MA infiltration in the lesion(s) through subcutaneous injections (n=90). Statistical analysis was performed through Fisher exact and Pearson Chi-square tests, Kruskal-Wallis, Kaplan-Meier and log-rank tests. Results: SR, AR and IL showed efficacy of 95.3%, 84.3% and 75.9%, with abandonment rate of 6.5%, 2.4% and 3.4%, respectively. IL patients had more comorbidities (58.9 %; p=0.001), age over 50 years (55.6%), and evolution time longer than 2 months (65.6%; p=0.02). Time for epithelialization and complete healing were similar in IL and IM MA groups (p=0.9 and p=0.5; respectively). Total AE and moderate to severe AE that frequently led to treatment interruption were more common in SR group, while AR and IL showed less toxicity. Conclusions/ Significance: AR and IL showed less toxicity and may be good options especially in CL cases with comorbidities, although SR treatment was more effective. IL treatment was an effective and safe strategy, and it may be used as first therapy option as well as a rescue scheme in patients initially treated with other drugs.