Pharmacokinetics of trimethoprim and sulfadiazine in the dog: urine concentrations after oral administration
Sigel, C.W.; Ling, G.V.; Bushby, S.R.; Woolley, J.L.; DeAngelis, D.; Eure, S.
American Journal of Veterinary Research 42(6): 996-1001
1981
ISSN/ISBN: 0002-9645 PMID: 7283250 Document Number: 181265
Serial blood samples were obtained from 12 healthy adult dogs given equivalent subcutaneous and oral doses of the antibacterial combination, trimethoprim-sulfadiazine (1:5). By using a 1-compartment open model, pharmacokinetic parameters for both drugs were estimated from the mean serum concentration data after oral administration. Trimethoprim and sulfadiazine were rapidly absorbed, reaching maximum concentrations in 1 and 4 hours with serum elimination half-lives of 2.5 and 9.9 hours, respectively. After a single oral dose (30 mg/kg, combined ingredients) was given, both drugs were present in urine for up to 24 hours at concentrations exceeding the minimum inhibitory concentrations for common pathogenic bacteria.