AMOXICILLIN PLUS CLAVULANIC ACID VS AMOXI CILLIN PLUS GENTAMICIN IN EMPIRICAL INITIAL TREATMENT OF URINARY-TRACT INFECTIONS IN HOSPITALIZED-PATIENTS

We compared the fixed combination amoxicillin plus clavulanic acid wit h that of amoxicillin plus gentamicin in the empirical initial treatme nt of severe urinary tract infections. The study included 87 hospitali zed patients (51 women and 36 men, mean age 58+/-22 years) with acute uncomplicated pyelonepritis (n = 48) or with complicated urinary tract infections (n = 39). 80 patients (92%) had fever and 31 patients (36% ) positive blood cultures. 45 patients were randomly assigned to amoxi cillin plus clavulanic acid and 42 to amoxicillin plus gentamicin. Ove rall, 18 patients (21%) were infected with organisms resistant in vitr o to amoxicillin plus clavulanic acid, whereas no pathogen was isolate d with resistance to amoxicillin plus gentamicin (p < 0.0001). At the end of the empirical treatment (4.2+/-1.5 days after the start), signi ficant bacteriuria was present in 6/39 patients (15%) assigned to amox icillin plus clavulanic acid, compared to 0/34 patients assigned to am oxicillin plus gentamicin (p < 0.05). The clinical response was satisf actory in both groups, and the time from start of therapy to resolutio n of fever was 2.2+/-1.4 days in the amoxicillin plus clavulanic acid group and 2.3+/-1.7 days in the amoxicillin plus gentamicin group. Alt hough the in-vitro resistance did not result in a lower clinical effic acy of amoxicillin plus clavulanic acid compared to amoxicillin plus g entamicin in our relatively small sample of patients, the data indicat e that the antimicrobial activity of amoxicillin plus clavulanic acid is inadequate to cover the spectrum of causative agents in hospitalize d patients with pyelonephritis or complicated urinary tract infections . Amoxicillin plus clavulanic acid should therefore not be used in the initial empirical treatment of these infections.