[Imipenem/cilastatin: in vitro activity, concentrations in plasma and prostatic adenoma and therapeutic results in patients with complicated urinary tract infections].

Minimal inhibitory concentrations (MICs) of imipenem, ceftazidime, piperacillin, tobramycin, azthreonam and carumonam were assessed for 400 urinary isolates from hospitalized patients with complicated and/or nosocomial urinary tract infections yielding greater than or equal to 10(5) colony forming units (cfu). More than 90% of the gram-negative pathogens were sensitive to all the antibiotics tested. However, only imipenem and piperacillin exhibited MIC90 values in the therapeutic range for gram-positive pathogens (approximately half of which were staphylococci and enterococci). Perioperative prophylaxis with 0.5 g imipenem/cilastatin administered at different time intervals before the operation (up to six hours) was performed in patients undergoing resection (n = 31), respectively enucleation (n = 1) of a prostatic adenoma or lithotriptic treatment (n = 4). Imipenem yielded peak plasma concentrations of 12.2 to 134.8 mg/l (mean 49.4 mg/l). The estimated half life time in these patients was approximately three hours. Considerable intra as well as interindividual variations were found for imipenem concentrations in prostatic adenoma. However, they were sufficiently high to reach sensitive pathogens (MICs up to 1 mg/l) for up to two-and-a-half hours. Up to six hours after dosing the concentrations in prostatic secretions ranged between 1 and 2 mg/l. A total of 20 urological patients suffering from complicated urinary tract infections (15 men, five women) received a short-term i.v. infusion of 0.5 mg imipenem/cilastatin t.i.d. for seven to 16 days (median seven days). In all these patients urines were sterile during therapy as well as one to two days after therapy. Follow-up examinations performed seven to ten days after the end of treatment in 19 of these patients showed ten patients to be free of infection (55%); these patients were classified as success. Seven patients (37%) presented a relapse (same pathogen) and two patients (10%) a re-infection (different pathogen). Imipenem/cilastatin was well tolerated locally and systemically.