Ethidium bromide: pharmacokinetics and efficacy against trypanosme infections in rabbits and calves.

Abstract

[14C]ethidium bromide has been used to determine drug levels in tissues and body fluids of rabbits and calves following intramuscular injection. Uninfected and Trypanosoma brucei- or Trypanosoma congolense-infected animals were studied. Blood and tissue fluid level reached a maximum with 1 h and then fell rapidly; after 96 h 80-90% of the radioactivity injected had been excreted, approximately one third in urine and two thirds in faeces. By 1 h after injection of 1 mg [14C]ethidium/kg into a T. congolense-infected calf, 70-80% of the radioactivity in blood was found to be bound to trypanosomes. Doses of 1 or 10 mg/kg were found not to be curative for T congolense or T. brucei infections in rabbits: drug treatment resulted in a period of sub-patent parasitaemia which was always followed by a relapse. Examination of the prophylactic action of ethidium in rabbits showed that the drug extended the pre-patent period following trypanosome inoculation but provided no absolute protection. A period of "apparent' prophylaxis observed after drug treatment of infected rabbits has been correlated with the presence of anti-trypanosome IgG in the serum.

• Authors: R J Gilbert, B A Newton
• Journal: Parasitology (Parasitology) Vol. 85 (Pt 1) Pg. 127-48 (Aug 1982) ISSN: 0031-1820 [Print] England
• PMID: 7122121 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Ethidium

Topics

• Animals
• Body Fluids (metabolism)
• Cattle
• Ethidium (blood, metabolism, therapeutic use)
• Feces (analysis)
• Rabbits
• Tissue Distribution
• Trypanosoma
• Trypanosoma brucei brucei
• Trypanosomiasis, African (drug therapy, metabolism)
• Trypanosomiasis, Bovine (drug therapy, metabolism)