The efficacy of pentamidine combined with allopurinol and immunotherapy for the treatment of patients with diffuse cutaneous leishmaniasis

A new treatment regimen was tested on patients with incurable diffuse cutan eous leshmaniasis (DCL) infected with Leishmania mexicana mexicana in Mexic o. Two patients with advanced stages of the disease were treated with polyc hemotherapy (pentamidine and allopurinol) combined with recombinant human i nterferon-gamma (rIFN-gamma). For determination of the best medication, par asites isolated from patient lesions were exposed to available drugs both a s promastigotes and as intracellular amastigotes. A synergistic effect was observed in vitro for the combination of pentamidine and allopurinol. Both patients were treated and recovered rapidly, but one of them developed insu lin-dependent type I diabetes because of pentamidine toxicity. The complica tion was controlled and both patients were discharged with an apparent para sitologic cure, but after 3 months the two patients began to relapse. Our r esults suggest that allopurinol-pentamidine polychemotherapy, involving red uced dosage of pentamidine, combined with rIFN-gamma is an alternative for DCL patients infected with L. m. mexicana.