In-vitro activities of paromomycin and lasalocid evaluated in combination against Cryptosporidium parvum

J Antimicrob Chemother. 1998 Feb;41(2):293-6. doi: 10.1093/jac/41.2.293.


Using a chemiluminescence immunoassay, paromomycin and lasalocid were shown to inhibit Cryptosporidium parvum growth in Madin-Darby canine kidney cells in a concentration-dependent manner. The median effective concentrations (EC50s) for paromomycin and lasalocid were 1184 mg/L and 0.4 mg/L, respectively. Neither drug was cytotoxic to host cells at concentrations up to five times their EC50s. Drug combination studies were conducted and the resulting data were analysed by the median-effect principle and combination index method. Statistically significant synergy was observed when combinations of paromomycin and lasalocid were used at ratios of 5000:1 and 2500:1. A possible mechanism for synergy is discussed.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cattle
  • Cryptosporidium parvum / drug effects*
  • Cryptosporidium parvum / growth & development
  • Dogs
  • Dose-Response Relationship, Drug
  • Drug Therapy, Combination
  • Flow Cytometry
  • Immunoassay / methods
  • Kidney / cytology
  • Kidney / parasitology
  • Lasalocid / pharmacology*
  • Lasalocid / toxicity
  • Luminescent Measurements
  • Paromomycin / pharmacology*
  • Paromomycin / toxicity
  • Propidium / pharmacokinetics


  • Propidium
  • Paromomycin
  • Lasalocid