Treatment of urinary tract infections with a combination of amoxicillin and clavulanic acid

A 10-day course of amoxicillin (250 mg)-potassium clavulanate (125 mg) was administered three times daily to 116 female college students with urinary tract infections. All of the bacterial isolates from these patients were susceptible to amoxicillin-potassium clavulanate in vitro; only 81.0% were susceptible to amoxicillin alone. Evaluations at 1 week after completion of this course showed that clinical and bacteriological cures had been achieved in 96.9% of those who completed therapy. Cures were sustained in 85.6% of the patients examined at 4 weeks after the end of therapy. Therapeutic responses were comparable, irrespective of the results of antibody-coated bacteria tests. All strains of Enterobacteriaceae isolated from the rectal and urogenital sites at 1 week after therapy were susceptible to amoxicillin-potassium clavulanate. The proportion of fecal Escherichia coli resistant to amoxicillin alone increased from 13.3% before therapy to 35.6% at 1 week after therapy. Adverse drug reactions consisted of gastrointestinal symptoms (9.8%) and rashes (4.1%). Sixteen patients (14.2%) developed symptomatic candida vaginitis by 1 week after therapy.