Clinical pharmacokinetics and pharmacodynamic target attainment of pazufloxacin in prostate tissue: Dosing considerations for prostatitis

The present study examined the clinical pharmacokinetics of pazufloxacin in prostate tissue and estimated the probability of target attainment for tissue-specific pharmacodynamic goals related to treating prostatitis using various intravenous dosing regimens. Patients with prostatic hypertrophy received prophylactic infusions of pazufloxacin (500 mg, n = 23; 1000 mg, n = 25) for 0.5 h prior to transurethral prostate resection. Drug concentrations in plasma (0.5-5 h) and prostate tissue (0.5-1.5 h) were measured by high-performance liquid chromatography and used for subsequent noncompartmental and three-compartmental analysis. Monte Carlo simulation was performed to evaluate the probability of target attainment of a specific minimum inhibitory concentration (MIC) in prostate tissue: the proportion that achieved both area under the drug concentration over time curve (AUC)/MIC = 100 and maximum concentration (Cmax)/MIC = 8. Prostatic penetration of pazufloxacin was good with mean Cmax ratios (prostate tissue/plasma) of 0.82-0.99 and for AUC, 0.80-0.98. The probability of reaching target MIC concentrations in prostate tissue was more than 90% for dosing schedules of 0.25 mg/L for 500 mg every 24 h (500 mg daily), 0.5 mg/L for 500 mg every 12 h (1000 mg daily), 1 mg/L for 1000 mg every 24 h (1000 mg daily), and 2 mg/L for 1000 mg every 12 h (2000 mg daily). Importantly, the 2000 mg daily regimen of pazufloxacin produced a profile sufficient to have an antibacterial effect in prostate tissue against clinical isolates of Escherichia coli and Klebsiella pneumonia with MIC values less than 2 mg/L.

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy. 2017 Sep 08 [Epub ahead of print]

Kogenta Nakamura, Kazuro Ikawa, Genya Nishikawa, Ikuo Kobayashi, Masahiro Narushima, Hiroyuki Muramatsu, Shingo Morinaga, Keishi Kajikawa, Yoshiharu Kato, Masahito Watanabe, Kenji Zennami, Kent Kanao, Norifumi Morikawa, Makoto Sumitomo

Department of Urology, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan. Electronic address: ., Department of Clinical Pharmacotherapy, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan., Department of Urology, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan., Department of Urology, Meitetsu Hospital, 2-26-11 Sako, Nishi-ku, Nagoya, 451-8511, Japan.