A Comparison of Seven Compounds for Giardiacidal Activity in Mus musculus

Abstract

Certain chemicals were administered to laboratory mice to observe their effect on Giardia muris. The compounds used were phthalofyne, amphotericin B, nystatin, lead arsenate, and a combination of nystatin and Atabrine. These drugs were administered orally with the exception of phthalofyne, which was injected intravenously. Results were compared to those of the reference drug Atabrine. The reference drug Atabrine, or a combination of Atabrine and nystatin, appeared to have the greatest giardiacidal value in the treatment of laboratory mice. Examination of the literature pertaining to the treatment of giardiasis has indicated that the drugs that have been employed did not completely remove the parasite Giardia from its hosts. There has been considerable variation in the results obtained, even with Atabrine, the drug usually accepted as the drug of choice for treating giardiasis. This work was undertaken in an attempt to find a compound with greater giardiacidal activity. One of the first known reports of successful treatment of giardiasis was that of Yakimoff et al. (1917) using salvarsan. Since that time there have been many reports on a wide variety of drugs, the majority concerned with the treatment of human giardiasis. GalliVallerio (1937) was the first to report the giardiacidal activity of Atabrine. Nutter et al. (1941) found that 0.3 g Atabrine administered orally for 5 days cured 13 of 14 cases of human giardiasis with a single treatment. Hartman and Kyser (1941) found Atabrine to be 97% efficient and many other authors have reported Atabrine as highly effective in the treatment of human giardiasis. Since Atabrine was shown to be effective, other antimalarial drugs have been tested for giardiacidal activity. Lamadrid-Montemayor (1954) reported amodiaquin to be Received for publication 29 March 1963. * Paper No. 5072. Scientific Journal Series, Minnesota Agricultural Experiment Station, St. Paul. This work was partially supported by the University of Minnesota Graduate School Fund. 100% effective in a single 0.6 g dose. Rosenberg and Neumann (1957) had poor results with this drug with only a 33% cure. Swartzwelder and Papenmaster (1947) and Gondard (1951) found chloroquine to be of little or no value against Giardia. R ports on the efficacy of drugs for the treatment of animal forms of Giardia are not so numerous. Armaghan (1937) used an organic arsenical aldersone and found it to be 95% effective in rats starved 4 days. Brumpt (1937) found that a 1% solution of Atabrine cured 80% of the Giardia muris infections in mice and Culbertson (1941) reported 100% efficacy of Atabrine on 20 rats and 10 mice. Hagen found the same drug 80% effective against chinchilla Giardia. Filice (1952) reported that he based the dosage of Atabrine used to treat rats on the approximate concentration of 0.1 g in the human intestine. Rats starved for 2 days and given 5 ml of aqueous Atabrine solution with a stomach tube showed this drug to be about 88% efficient for the treatment of rat giardiasis. Karapetyan (1960a) first suggested a fungistat as a giardiacide. He used nystatin to eliminate Candida from in vitro Giardia cultures and found that concentrations of 180 units/ml and 360 units/ml destroyed Giardia in 2 days, but the fungi remained viable. In a second publication on in vitro culture of Giardia, Karapetyan (1960b) reported that nystatin effectively removed Candida guilliermondi from his media and the Giardia failed