Elimination of Trimethoprim, Sulphadoxine and their Metabolites in Goats

The elimination of trimethoprim and sulphadoxine after intravenous administration has been investigated in experiments on goats. Trimethoprim is metabolized to a great extent in the goat liver and the biliary excretion was almost equal to the urinary excretion in experiments with continuous intravenous infusion of trimethoprim. More than 99 % of the amount excreted in bile consists of metabolites of trimethoprim. In contrast it was almost exclusively the unchanged drug which was excreted in the saliva. Sulphadoxine is metabolized to a much smaller extent in goats than trimethoprim and the biliary and salivary excretion seemed without significance in comparison to the urinary excretion.