Assessment of ivermectin therapeutic efficacy on third-stage larvae of Lagochilascaris minor in mice experimentally infected.
In this study we evaluated the potential action of ivermectin on third-stage larvae, both at migratory and encysted phases, in mouse tissues after experimental infection with Lagochilascaris minor. Study groups I and II consisted of 120 mice that were orally administered 1,000 parasite eggs. In order to assess ivermectin action upon migratory larvae, group I (60 mice) was equally split in three subgroups, namely I-A, I-B, and I-C. On the 7th day after inoculation (DAI), each animal from the subgroup I-A was treated with 200 micrograms/Kg ivermectin while subgroup I-B was given 1,000 micrograms/Kg, both groups received a single subcutaneous dose. To assess the drug action on encysted larvae, group II was equally split in three subgroups, namely II-A, II-B, II-C. On the 45th DAI each animal was treated with ivermectin at 200 micrograms/Kg (subgroup II-A) and 1,000 micrograms/Kg (group II-B) with a single subcutaneous dose. Untreated animals of subgroups I-C and II-C were used as controls. On the 60th DAI all animals were submitted to larva search. At a dose of 1,000 micrograms/Kg the drug had 99.5% effectiveness on third-stage migratory larvae (subgroup I-B). Ivermectin efficacy was lower than 5% on third-stage encysted larvae for both doses as well as for migratory larvae treated with 200 micrograms/Kg.
Barbosa
C A
CA
Parasitology Department/IPTSP/UFG, Goiânia-GO, Brazil.
Campos
D M
DM
de Oliveira
J A
JA
D000818:Animals; D000969:Antinematodal Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D005260:Female; D007559:Ivermectin / Q000494:pharmacology / Q000627:therapeutic use*; D007814:Larva / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009348:Nematoda / Q000187:drug effects; D009349:Nematode Infections / Q000188:drug therapy*
D000969:Antinematodal Agents; D007559:Ivermectin