Efficacy of two trimethoprim-sulphonamide combinations in experimental pyelonephritis in the rat

Co-trimazine, a new combination of trimethoprim and sulphadiazine intended for treatment of urinary tract infections, was tested and compared to co-trimoxazole in an experimental model of acute, obstructive pyelonephritis in the rat. The tests were carried out at four dose levels corresponding to the clinically recommended doses and to 1/4, 1/2, and 3/4 of the latter. The drugs were administered orally. Co-trimazine was found to have a greater antibacterial activity than co-trimoxazole and its use at a lower dosage than that of the latter appears warranted.