Preliminary Report Comparing Piperacillin and Carbenicillin for Complicated Urinary Tract Infections

Abstract

Piperacillin is a new semisynthetic penicillin with a broad spectrum of in vitro activity against common gram-negative urinary tract pathogens. We compared the efficacy and safety of piperacillin versus carbenicillin in patients with complicated urinary tract infection. A total of 56 adult patients (mean age 55 years) in stable medical condition with 1 or more structural genitourinary abnormalities entered the study. Of these patients 27 were evaluated for antibiotic efficacy. There were 20 lower tract and 7 upper tract infections, of which 17 were acute and 10 were chronic. Patients were randomized into 2 groups: 17 patients with 18 organisms received single agent treatment with 181 mg. per kg. intravenous piperacillin daily for 6 days and 10 patients with 11 organisms received 270 mg. per kg. intravenous carbenicillin daily for 6 days. Infecting organisms were Escherichia coli 45 per cent, Proteus mirabilis 14 per cent, Klebsiella pneumoniae 14 per cent. Enterobacter species 10 per cent, Pseudomonas aeruginosa 7 per cent and so forth. Antimicrobial susceptibility assessed by measurement of minimal inhibitory concentration and disk diffusion zone size demonstrated superior activity of piperacillin over carbenicillin for most micro-organisms tested. All patients responded clinically. The bacteriologic cure rate was 72 per cent at 5 to 9 days after therapy in both groups. Three patients who received piperacillin had urosepsis and were cured. No resistance emerged during therapy. Superinfections developed in 5 patients on carbenicillin (50 per cent) and in 4 patients on piperacillin (24 per cent), and none was resistant to piperacillin. Superinfections were attributed to catheterization and structural genitourinary abnormalities. The over-all incidence of adverse effects in patients on piperacillin was less than that of those on carbenicillin, 31 and 51 per cent respectively. Side effects in both groups were mild and did not require discontinuation of therapy. There were no significant alterations in fluid and electrolyte balance, or hematologic or renal function.

Apalcillin Treatment of Complicated Urinary Tract Infections

“…In our controlled clinical trial, apalcillin therapy for complicated urinary tract infections produced a 61.5% bacteriologic cure rate, which was comparable to pooled results from controlled and uncontrolled unpublished studies, which were conducted by the investigational drug sponsor [5], However, in contrast to mezlocillin, azlocillin and piperacillin, which yield bacteriologic cure rates of 68-78% [1,7,9,10], apalcillin appears to be slightly inferior in efficacy. Failures to apalcillin in our study may be due to several factors: presence of uncorrectable genitourinary tract abnormalities, or develop ment of bacterial resistance.…”

“…Eight (38.1%) had upper tract and 13 (61.9%) had lower tract UTI (table I). There were 25 anatomic or functional (genitourinary tract) abnormali ties, which included benign prostatic hypertrophy (6), renal calculi (4), urethral stricture (3), bladder neoplasm (3), and others (9). Nine (36%) abnormalities were cor rected during the study (table II).…”

Comparative Efficacy of Piperacillin versus Carbenicillin for Complicated Urinary Tract Infections

“…Piperacillin is such an agent. It is of particular interest for treatment of complicated urinary tract infection because of its superior coverage of aerobic gram-negative bacilli, notably the Klebsiella species, the indole-positive Proteus species, some strains of Serratia marcescens and P. aeru ginosa [11]. In addition, it is as effective as penicillin G against group D streptococci [3], is synergistic with ami noglycosides, and has successfully eradicated carbcnicillin-resistant organisms in some cases [4].…”