Concentrations of trimethoprim and sulphamethoxazole in the human prostate gland after intramuscular injection.

Following intramuscular injection of co-trimoxazole (trimethoprim/sulphamethoxazole 1 : 5), concentrations of trimethoprim (TMP) and sulphamethoxazole (SMX) were measured in the prostatic tissue and serum of 30 men undergoing endoscopic prostatectomy. Tissue levels for TMP appeared to be higher than serum levels and probably reached the minimum inhibitory concentration (MIC) for most urinary pathogens. Administration of the drug at 4, 8 and 12 h prior to sampling produced no significant difference in tissue levels. It is concluded that TMP is concentrated in prostatic tissue following intramuscular injection. Tissue levels for SMX were apparently lower than serum levels.