Comparison of cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis and L. (V.) guyanensis in Brazil: therapeutic response to meglumine antimoniate.

Abstract

We conducted a quasi-experimental study to compare the response to meglumine antimoniate in patients with localized cutaneous leishmaniasis from two endemic areas of Brazil that were infected by two Leishmania species. Sixty-one were infected by Leishmania (Viannia) braziliensis (group B) and 57 by L. (V.) guyanensis (group G). All had a parasitologically proven diagnosis and were treated with 20 mg of pentavalent antimonial (Sb V)/kg/day given intravenously or intramuscularly for 20 days. Main outcomes were diagnosed using clinical criteria three months after treatment and patients were followed for six months. Intention-to-treat analysis showed a higher failure rate in group G (relative risk [RR] ϭ 1.5, 95% confidence interval [CI] ϭ 1.1-2.0, 2 ϭ 7.44, P ϭ 0.006). The analysis using an explanatory approach including 52 patients from group B and 49 from group G, who were regularly treated and followed for six months, showed a low cure rate (50. 8% in group B and 26.3% in group G) with a greater risk of failure in the latter group (RR ϭ 1.7, 95% CI ϭ 1.2-2.5, 2 ϭ 8.56, P ϭ 0.003). The effect of the etiologic agent remained significant after adjusting for age, disease duration, and site and number of lesions that were identified as predictors of failure in a logistic regression model. We concluded that Leishmania species constitute an important factor in predicting the outcome of cutaneous leishmaniasis treated with a pentavalent antimonial.

Fatores associados ao insucesso do tratamento da leishmaniose cutânea com antimoniato de meglumina

“…Não se pode também descartar a influência de fatores farmacológicos ainda não descritos, que justifiquem a associação entre peso e insucesso do tratamento da LTA com antimoniato de meglumina, uma vez que o desenvolvimento e a pesquisa de drogas para o tratamento deste grupo de patologias são freqüentemente negligenciados 14 17 . O impacto de diferentes dosagens de antimonial sobre a eficácia, embora não tenha sido demonstrado nesta coorte, pode refletir a ocorrência de espécies de Leishmania com diferentes perfis de sensibilidade a esse grupo de drogas, o que já vem sendo observado há muitos anos 26 , levando inclusive alguns pesquisadores a sugerir a utilização de esquemas com dosagens individualizadas, de acordo com a síndrome clínica e espécie envolvidas 17 . Contudo, o resultado observado neste coorte pode sugerir que as espécies e/ou isolados de Leishmania que circulam em nossa região são menos susceptíveis a dosagens baixas de antimoniato de meglumina, embora estudos observacionais com um maior número de pacientes e ensaios clínicos prospectivos sejam mais adequados para elucidar tais aspectos da terapêutica.…”

New delivery systems for amphotericin B applied to the improvement of leishmaniasis treatment

“…These drugs are effective, presenting an effi cacy of approximately 90% (17) , but there has been growing evidence of variable effi cacy that depends on the species, geographic region, presence of resistant strains, and therapeutic schemes employed (18) (19) (20) . Moreover, certain factors, such as the need for parenteral administration for up to 30 days, the high frequency of side effects such as myalgia, arthralgia, anorexia, fever and urticaria, and signifi cant toxicity to the liver, kidneys and spleen of the patient, have contributed to the limited use of these drugs in clinical practice (21) (22) .…”

Failure of both azithromycin and antimony to treat cutaneous leishmaniasis in Manaus, AM, Brazil

“…Leishmaniasis has been treated for decades with pentavalent antimony, pentamidine or amphotericin B but patients cure rate presents high variability depending on Leishmania spp., clinical picture and geographical location (SARAVIA et al, 1989;ROMERO et al, 2001). …”