Prostatic Pharmacokinetic/Pharmacodynamic Evaluation of Ampicillin‐Sulbactam for Bacterial Prostatitis and Preoperative Prophylaxis

This study aims to define the penetration of ampicillin and sulbactam into prostate tissue, develop a prostatic pharmacokinetic model of each drug and assess the appropriateness of ampicillin-sulbactam regimens for the treatment of prostatitis and the prophylaxis of postoperative infection, based on a pharmacokinetic and pharmacodynamic simulation. Subjects were prostatic hyperplasia patients prophylactically receiving a 0.5-h infusion of 1.5 g (1 g:0.5 g) or 3 g (2 g:1 g) ampicillin-sulbactam before transurethral resection of the prostate. Ampicillin and sulbactam concentrations in plasma and prostate tissue were measured. The prostate tissue/plasma ratios of both ampicillin and sulbactam were approximately 0.37 (area under the drug concentration-time curve) and penetration was similar. The prostatic population pharmacokinetic model, included a covariate analysis, adequately predicted prostate tissue concentrations in our patient population. For therapeutic use, aiming for a bactericidal target of 50% of time above minimum inhibitory concentration (T > MIC) in prostate tissue, 3 g ampicillin-sulbactam four times daily achieved ≥90% expected probability against only E. faecalis in typical patients with a creatinine clearance (CLcr ) = 30 mL/min. For prophylactic use, aiming for a bacteriostatic target of 30% T > MIC, 3 g ampicillin-sulbactam four times daily achieved ≥90% expected probability of attaining the bacteriostatic target against E. faecalis and Proteus species when CLcr = 30 mL/min. Based on prostatic simulations, the present study provides helpful recommendations for the treatment of bacterial prostatitis and preoperative prophylaxis in prostatectomy. This article is protected by copyright. All rights reserved.