K. Kleinow, Wendy L. Beilfuss, H. Jarboe
May 1, 1992
Citations
2
Influential Citations
29
Citations
Journal
Canadian Journal of Fisheries and Aquatic Sciences
Abstract
Sulfadimethoxine (SDM), a sulfonamide antibacterial drug, was examined in regards to bioavailability, pharmacokinetics, distribution, plasma protein binding, mass balance, and metabolism in the rainbow trout (Oncorhynchus mykiss). Analysis of SDM pharmacokinetics when determined by 35S counting (parent/metabolite combination) and HPLC (parent) provided estimates for t1/2α, t1/2β, Vss, and Clb, of 0.63/0.38 (h), 17.0/15.9 (h), 500.8/421.6 (mL/kg), and 22.7/21.8 mL∙kg−1∙h−1, respectively. Multiple dose administration of [35S]SDM resulted in a terminal t1/2 of 35.2 h. Sodium SDM (42 and 126 mg/kg) and free drug (42 mg/kg) oral bioavailabilities were 63, 50, and 34%, respectively. Plasma protein binding (15.8 ± 5.1%) was nonsaturable and nonspecific. Tissues attained the highest levels of SDM equivalents in the bile followed by the intestine, liver, blood, skin, kidney, spleen, gill, muscle, and fat, respectively. Mass balance studies demonstrated a minor role for branchial ((0.6 ± 0.24%) 25 h) and urinary ((...