Trimethoprim prostate infections

A combination of trimethoprim-sulfamethoxazole is effective treatment for a wide variety of infections including P jiroveci pneumonia, shigellosis, systemic salmonella infections, urinary tract infections, prostatitis, and some nontuberculous mycobacterial infections. It is active against most Staphylococcus aureus strains, both methicillin-susceptible and methicillin-resistant, and against respiratory tract pathogens such as the pneumococcus, Haemophilus sp, Moraxella catarrhalis, and Klebsiella pneumoniae (but not Mycoplasma pneumoniae). However, the increasing prevalence of strains of E coli (up to 30% or more) and pneumococci that are resistant to trimethoprim-sulfamethoxazole must be considered before using this combination for empirical therapy of upper urinary tract infections or pneumonia. 

The antibacterial spectrum of trimethoprim is similar to that of sulfamethoxazole (see p. 290) however, trimethoprim is 20 to 50 times more potent than the sulfonamide. Trimethoprim may be used alone in acute urinary tract infections and in the treatment of bacterial prostatitis (though fluoroquinolones are preferred). 

Fate Both agents distribute throughout the body. Trimethoprim concentrates in the relatively acidic milieu of prostatic and vaginal fluids and accounts for the use of the trimethoprim-sulfamethoxazole combination in infections at these sites. Both parent drugs and their metabolites are excreted in the urine. 

Treatment of uncomplicated lower urinary tract infections with trimethoprim—sulfamethoxazole often is highly effective for sensitive bacteria, usually for a minimum of 3 days. The combination is especially useful in chronic and recurrent infections of the urinary tract. Trimethoprim also is found in therapeutic concentrations in prostatic secretions, and trimethoprim—sulfamethoxazole is often effective for bacterial prostatitis. 

Chronic bacterial prostatitis occurs when acute bacterial prostatitis has been inadequately treated because of pathogen resistance, relapse, or short-course therapy or because of blocked drainage of secretions from the prostate. Most men with chronic prostatitis will have had a previous bout of acute prostatitis. The most common clinical feature of chronic prostatitis is recurrent urinary tract infections and the symptoms and complaints of acute bacterial prostatitis. Fluoroquinolones, trimethoprim-sulfamethoxazole, doxycycline, and nitrofurantoin are used in the management of chronic prostatitis. Chronic prostatitis warrants at least 10 to 12 weeks of therapy. Poor clinical outcomes, however, have been observed because of poor diffusion of antimicrobials into the prostate. 

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