title: Furazolidone disposition after intravascular and oral dosing in the channel catfish.
abstract: 1. The pharmacokinetics, tissue distribution and excretion of the nitrofuran drug furazolidone have been examined in the channel catfish. [14C]Furazolidone was administered by intravascular or oral routes in a single dosage of 1 mg/kg body weight. 2. A two-compartment pharmacokinetic model best described parent furazolidone concentrations in the plasma after intravascular dosing. Elimination of parent compound was extremely rapid, with a terminal half-life of 0.27h and total body clearance of 1901 ml/h/kg. 3. After oral dosing, furazolidone concentrations in the plasma were highest at 1 h and were below the limit of determination (< 20 ng/ml) at 5 h. The oral bioavailability of parent furazolidone administered in solution was 58%, compared with 28% in a feed mixture. 4. Concentrations of furazolidone and its metabolites were highest in the excretory tissues and lowest in the muscle after oral dosing. Parent furazolidone comprised 10% of the total 14C in the muscle at 8 h and was not detectable (< 1 ng/g) at 24 h; total 14C concentrations declined from 274 to 59 ng furazolidone equiv./g between 8 and 168 h. Non-extractable (bound) residues comprised 18% of total 14C in muscle at 8 h and 33% at 168h. 5. Renal excretion was the primary route of elimination of 14C residues and accounted for nearly 55% of the oral dose.
authors.affiliation: Gulf Coast Seafood Laboratory, US Food and Drug Administration, Dauphin Island, AL 36528.
authors.forename: S M
authors.initials: SM
authors.lastname: Plakas
authors.forename: K R
authors.initials: KR
authors.lastname: el Said
authors.forename: G R
authors.initials: GR
authors.lastname: Stehly
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001822:Body Burden; D005664:Furazolidone / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000652:urine; D007059:Ictaluridae / Q000378:metabolism*; D009132:Muscles / Q000737:chemistry / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects
chemical_list: D001798:Blood Proteins; D005664:Furazolidone