Successful Topical Treatment of Murine Cutaneous Leishmaniasis with a Combination of Paromomycin (Aminosidine) and Gentamicin

The study tested a new topical formulation, WR 279,396, containing paromomycin (15%) and gentamicin (0.5%), for treating cutaneous leishmaniasis in BALB/c mice. The treatment was applied twice daily for 10 days on 60-day-old lesions, with results observed over 70 days. WR 279,396 achieved 100% healing without relapse for lesions caused by Leishmania major, Leishmania mexicana, Leishmania panamensis, and Leishmania amazonensis. In comparison, the paromomycin-MBCL formulation healed 83% of L. major lesions without relapse, while the paromomycin-urea formulation saw 100% initial healing of L. major lesions but a 30% relapse rate. WR 279,396 was non-toxic and promoted hair growth, healing, and reduced scar size, indicating a potential cosmetic benefit.