Acute epididymitis is a common urologic condition; effective treatment is necessary to avoid recurrence and complications such as chronic pain and infertility. With resistance among major pathogens growing, it is important that dosing regimens are selected based on PK/PD characteristics as well as antimicrobial activity profiles. Therefore, this study investigated the distribution and activity of levofloxacin and sitafloxacin into epididymal tissue.

One hour before orchiectomy, 18 patients with prostate cancer (mean age, 77 years), received either levofloxacin 500 mg (n = 9) or sitafloxacin 100 mg (n = 9) and 0.5 g of epididymal tissue and blood samples were collected during surgery. Drug concentrations were measured by high-performance liquid chromatography; linear regression analysis was performed and PK data analysed by the MULTI program.

The mean ratio of epididymal to serum concentration was 1.48 ± 0.45 for levofloxacin and 1.54 ± 0.81 for sitafloxacin. The Cmax in serum and epididymal tissue was 8.84 μg/ml, 14.1 μg/g, respectively.   The AUC24 in serum and epididymal tissue for levofloxacin, was 68.5 μg h/ml  and 108.9 μg h/g, respectively. For sitafloxacin, the Cmax was 1.22 μg/ml in serum and 1.66 μg/g in epididymal tissue, and the AUC24 was 9.58 μg h/ml in serum and 13.1 μg h/g in epididymal tissue. Both regimens were well tolerated with no treatment-related adverse events nor postoperative urogenital infections observed.

Although only a limited number of cases were included in each arm, the results are useful because few other studies have investigated epididymal concentrations and PK/PD properties of these two fluoroquinolones. Researchers concluded that oral administration of levofloxain 500 mg or sitafloxacin 100 mg achieves effective epididymal concentrations for treatment of epididymitis.

PMID: 28089362

J Infect Chemother. 2017 Apr;23(4):214-217. doi: 10.1016/j.jiac.2016.12.010.

Source: https://www.ncbi.nlm.nih.gov/pubm ed/28089362?dopt=Abstract