The Therapeutic and Prophylactic Properties of Antrycide in Trypanosomiasis of Cattle

Differences in sensitivity of KenyanTrypanosoma vivax populations to the prophylactic and therapeutic actions of isometamidium chloride in Boran cattle

“…Differences between the prophylactic and therapeutic activity of a drug have also been reported for the 2,7-di-m-amidinophenyldiazoamino derivative of homidium (Berg, Brown, Hill and Wragg, 1961), another member of the phenanthridine series of compounds to which isometamidium belongs. Fiennes (1953) and Whiteside (1958) suggested that a decrease in the prophylactic activity of a trypanocide may be due to a rapid increase in expression of resistance when trypanosomes are inoculated into an animal under prophylaxis. The findings described here suggest that the form(s) of isometamidium exerting the drug's therapeutic activity may be different from the form(s) exerting the prophylactic activity.…”

“…This variation in prophylaxis could be due to a number of factors: vector density or level of trypanosomiasis risk (Davey, 1957;Whiteside, 1962), relapses I Present address: Department of Veterinary Parasitology, University of Glasgow Veterinary School, Glasgow G61 1QH, UK. 784. 29 30 PEREORINE, MOLOO AND WHITELAW from tissue sites inaccessible to the drug (Jennings, Whitelaw and Urquhart, 1977), acquisition of immunity following the use of trypanocides (Fiennes, 1953;Wilson, Le Roux, Paris, Davidson and Gray, 1975;Wilson, Paris, Luckins, Dar and Gray, 1976;Bourn and Scott, 1978), dosage of drug (Boyt, Lovemore, Pilson and Smith, 1962), infection at the time of treatment (Davey, 1957) and differing levels of drug sensitivity between trypanosome populations. 784. 29 30 PEREORINE, MOLOO AND WHITELAW from tissue sites inaccessible to the drug (Jennings, Whitelaw and Urquhart, 1977), acquisition of immunity following the use of trypanocides (Fiennes, 1953;Wilson, Le Roux, Paris, Davidson and Gray, 1975;Wilson, Paris, Luckins, Dar and Gray, 1976;Bourn and Scott, 1978), dosage of drug (Boyt, Lovemore, Pilson and Smith, 1962), infection at the time of treatment (Davey, 1957) and differing levels of drug sensitivity between trypanosome populations.…”

Derivation and characterization of a quinapyramine-resistant clone of Trypanosoma congolense

“…Between the 1950s and 1970s quinapyramine was widely used in Africa as a therapeutic and prophylactic agent in cattle (8,26). Resistance to the compound appeared to develop rapidly (28,34) and was often associated with concomitant cross-resistance to isometamidium, homidium, and diminazene (18,31).…”

“…However, it was impossible to ascertain whether the apparent cross-resistance actually was cross-resistance or reflected difficulties in interpreting fieldderived data. In 1976, quinapyramine ceased to be manufactured (13) because of the ease with which resistance appeared to develop (8,14,22) and because of problems with drug toxicity (7). However, in 1984 the compound was reintroduced to the market, but only for use in camels (27).…”

“…Using a similar procedure, Fiennes (8) failed to induce resistance in a stock of T. congolense. In contrast, a similar protocol successfully induced resistance to quinapyramine in Trypanosoma equiperdum (11,24), T. congolense (12), and Trypanosoma evansi (10).…”