title: Absorption of two trimethoprim/sulphonamide combinations from the uterus of pony mares.
abstract: Plasma drug concentrations were measured after two commercially available potentiated sulphonamides, trimethoprim and sulfadoxine and trimethoprim and sulphadiazine, were infused daily for 2 and 3 days, respectively, into the uteri of pony mares which had been mated before ovulation. Intravenous administration of trimethoprim and sulfadoxine allowed uterine absorption of trimethoprim (23-43%) and sulfadoxine (29-34%) to be calculated. After intra-uterine administration trimethoprim and sulphadiazine were detected in the milk of a lactating mare. In order to maintain plasma concentrations likely to be required for clinical efficacy of both drugs they should be administered every 12 h. However, infusions of both preparations caused endometrial inflammation as assessed by cytological and histological examination and this may have been responsible for the low pregnancy rate.
authors.affiliation: Department of Surgery and Obstetrics, Royal Veterinary College, Hatfield, Herts, UK.
authors.forename: E H
authors.initials: EH
authors.lastname: Boyd
authors.forename: W E
authors.initials: WE
authors.lastname: Allen
mesh_terms: D000042:Absorption; D000818:Animals; D004338:Drug Combinations; D005260:Female; D006736:Horses / Q000378:metabolism*; D007774:Lactation / Q000378:metabolism; D008892:Milk / Q000032:analysis; D011247:Pregnancy; D013411:Sulfadiazine / Q000493:pharmacokinetics*; D013413:Sulfadoxine / Q000493:pharmacokinetics*; D013424:Sulfanilamides / Q000493:pharmacokinetics*; D014295:Trimethoprim / Q000493:pharmacokinetics*; D014599:Uterus / Q000378:metabolism*
chemical_list: D004338:Drug Combinations; D013424:Sulfanilamides; D013411:Sulfadiazine; D013413:Sulfadoxine; D014295:Trimethoprim