Use of Trimethoprim Alone or in Combination with Drugs Other Than Sulfonamides

Experimental data, pharmacokinetic results, and clinical trials suggest that trimethoprim (TMP) is effective when used alone and is not associated with the toxicity and adverse effects caused by sulfonamides. Because an analysis of in vitro, pharmacokinetic, and clinical data suggested that the combination of rifampicin and TMP (Rifaprim) would be safe and highly active, an eight-year study of this combination for the treatment of urinary tract infection was done. The results were encouraging. Furthermore, a large multicenter trial of Rifaprim in 800 patients showed Rifaprim to be superior to trimethoprim-sulfamethoxazole for the treatment of chronic infections of the upper urinary tract. In another controlled trial, Rifaprim proved valuable for the treatment of urinary tract infections that resisted eradication and recurred frequently. Evidence suggests that Rifaprim may be useful in the treatment of other disease, such as staphylococcal osteitis (especially that caused by highly resistant organisms). Unlike antibiotics such as gentamicin, the use of which requires hospitalization of the patient and careful monitoring of levels in blood, Rifaprim can be used at home. Thus the danger of nosocomial infection is avoided.