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

The study investigated the efficacy of a new topical formulation, WR 279,396, which combined paromomycin (15%) and gentamicin (0.5%), in 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. For ulcers caused by Leishmania major or Leishmania mexicana, 100% of lesions treated with WR 279,396 healed by day 20 without relapse by day 70, outperforming other formulations. For Leishmania panamensis or Leishmania amazonensis, all lesions treated with WR 279,396 healed without relapse, whereas less than 50% of lesions treated with paromomycin-MBCL healed by day 30, with all relapsing by day 70. WR 279,396 was non-toxic and appeared to promote hair growth, healing, and limit scar size.