Disposition and metabolism of carbovir in mice dosed intravenously or orally.
To determine the disposition of carbovir and [3H]carbovir in mice, HPLC and thin-layer chromatographic assays were developed and mice were dosed iv and by gavage. Carbovir had no lethal effect at iv doses up to 500 mg/kg and was stable for 24 hr in mouse plasma at temperatures ranging from 0-37 degrees C. Binding to plasma proteins was minimal. Following an iv dose of 500 mg/kg of carbovir or [3H] carbovir, elimination phases with half-lives of 26-37 min (alpha) and 206-330 min (beta) were observed for plasma. For mice dosed with 27 mg/kg of [3H]carbovir, however, only a single phase with a half-life of 17 min was noted. Of several tissues examined, kidney contained the highest concentration of radioactivity. For the high dose, 19.0 +/- 2.6% was excreted in the urine in 24 hr as unchanged carbovir and 42.2 +/- 2.4% as metabolites; for the low dose, 54.5 +/- 6.1% was excreted as carbovir and 26.5 +/- 5.0% as metabolites. When mice were dosed orally with 500 mg/kg, plasma concentrations of carbovir were low. The initial plasma half-life for carbovir was 69 min; the terminal half-life was 822 min. Urinary excretion of unchanged carbovir was 21.3 +/- 7.1%. These results indicate that clearance of high doses of carbovir is limited and that its absorption is poor after oral dosing.
el Dareer
S M
SM
Biochemistry Research Department, Southern Research Institute, Birmingham, AL 35255-5305.
Tillery
K F
KF
Rose
L M
LM
Struck
R F
RF
Hill
D L
DL
D000284:Administration, Oral; D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D015224:Dideoxynucleosides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006207:Half-Life; D007275:Injections, Intravenous; D051379:Mice; D008815:Mice, Inbred Strains; D014018:Tissue Distribution
D000998:Antiviral Agents; D015224:Dideoxynucleosides; C057503:carbovir