Comparison of the effectiveness of two topical paromomycin treatments versus meglumine antimoniate for New World cutaneous leishmaniasis

Abstract

The randomized, controlled study compared the therapeutic efficacy and safety of two paromomycin-containing topical preparations with the gold treatment standard, meglumine antimoniate, and with each other in 120 Ecuadorian patients with ulcerated lesions. The two paromomycin treatment comparisons were double-blinded. Group 1 ( n=40) received 15% paromomycin plus 12% methylbenzonium chloride (PR–MBCL) dissolved in a soft white paraffin base, applied twice daily for 30 days. Group 2 ( n=40) was also treated for 30 days with 15% paromomycin plus 10% urea (PR–U) dissolved in the same paraffin base. Group 3 ( n=40) received 20 mg/kg/day of IM meglumine antimoniate (MA) for 10 days as per Ecuadorian Ministry of Public Health recommendations at the time of the study. The 10-day treatment was completed by 90% of the MA group compared to 72.5% of the PR–MBCL ( X 2=4.0, P=0.045) and 75% of the PM–U ( X 2=3.1, P>0.05) groups whose treatment regime lasted 20 days longer than the MA treatment. Post-treatment lesion burning, redness, inflammation, and soreness were more common in the two paromomycin groups compared to MA group ( P<0.05). The frequency of treatment-related side effects in the two paromomycin groups was similar. Six weeks after the start of treatment, 80.6% of MA subjects were clinically cured compared to 48.3% in the PR–MBCL ( X 2=6.1, P=0.014) and 40% in the PM–U groups ( X 2=12.6, P=0.002). By 12 weeks, the proportion of clinically cured subjects in the MA (91.7%) compared to PM–MBCL (79.3%) or PM–U (70%) groups was not significantly different ( P>0.05). MA-treated subjects clinically cured by 12 weeks had a faster mean healing time (29.5±12.2 days) compared to those in the PM–MBCL (versus 43.1±14.4 days, t=−3.7, P=0.001) or PR–U groups (43.5±17 days; t=−3.2, P=0.002). During the 48-week post-treatment follow-up period, infection reactivation was observed in 15.2% of the MA subjects compared to 17.4% in the PM–MBCL and 10.5% PM–U of subjects diagnosed as clinically healed by 12 weeks ( P>0.05). The results suggest that although the time required for the clinical healing of ulcerated lesions takes longer, topical paromomycin may be an acceptable therapeutic alternative in endemic areas where meglumine antimoniate is not available, is too costly or medically contraindicated.