Pharmacokinetics, bioavailability and tissue residues of [14C]isometamidium in non-infected and Trypanosoma congolense-infected Boran cattle.
In this paper, pharmacokinetics, bioavailability and tissue residues are reported in non-infected and Trypanosoma congolense-infected Boran steers following either intravenous or intramuscular injection of [14C]isometamidium at a dose rate of 1 mg kg-1 body weight. Two differently labelled compounds of isometamidium were used; 6-14C (ISMM-1) and ring-U-14C (ISMM-2). The cattle were divided into 5 groups: group 1 consisted of 3 non-infected cattle treated with ISMM-1 by intravenous injection; group 2 consisted of 2 non-infected cattle treated with ISMM-1 by intramuscular injection; group 3 consisted of 2 Trypanosoma congolense-infected cattle given similar treatment as group 2 cattle; group 4 consisted of 3 non-infected and group 5 of 2 infected cattle treated with ISMM-2 by intramuscular injection. Radioactivity was measured in plasma, urine, faeces and tissues, and drug concentrations were calculated. Data obtained following i.v. treatment were best described by tri-exponential equations with half-lives of 0.13, 1.22 and 120.7 h. Bioavailability of the intramuscular dose was 58% in group 2 cattle. The major route of excretion was in faeces. Approximately 80% of the intravenous dose given was excreted within 21 days out of which only 18% was through urine. Total residues accounted for approximately 15% the total dose given. Drug residues remained high in organs with excretory functions including the liver and kidneys.
Radioisotope Laboratory, Kenya Trypanosomiasis Research Institute, Kikuyu, Kenya.
G A
GA
Murilla
R E
RE
Mdachi
W M
WM
Karanja
D000818:Animals; D002417:Cattle; D005243:Feces / Q000737:chemistry; D007668:Kidney / Q000737:chemistry; D007700:Kinetics; D008099:Liver / Q000737:chemistry; D008297:Male; D010617:Phenanthridines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D010949:Plasma / Q000737:chemistry / Q000378:metabolism; D014344:Trypanocidal Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D014348:Trypanosoma congolense; D014353:Trypanosomiasis, African / Q000188:drug therapy*; D014556:Urine / Q000737:chemistry
D010617:Phenanthridines; D014344:Trypanocidal Agents; C000702:isometamidium chloride