Activity of halogeno-thiazolides against Cryptosporidium parvum in experimentally infected immunosuppressed gerbils (Meriones unguiculatus).

Nitazoxanide and three halogeno-thiazolides, RM-4850, RM-4865, and RM-5038, were tested against Cryptosporidium parvum in experimentally infected immunosuppressed Mongolian gerbils. Daily 400-mg/kg doses of the four test drugs for 5 to 8 consecutive days produced similar reductions of oocyst shedding. Using early-infected gerbils, a shorter 4-day treatment with RM-5038 reduced oocyst shedding by 95%, compared to 47% for nitazoxanide (P = 0.02), suggesting that RM-5038 is more effective than nitazoxanide under the experimental conditions used.