title: Determination of the concentration of ciprofloxacin in prostate tissue following administration of a single, 1000 mg, extended-release dose.
abstract: OBJECTIVE
  Infection is a potential complication of transrectal needle biopsy of the prostate (TRNBP), and antibiotic prophylaxis with a fluoroquinolone is commonly used. The objective of this study was to demonstrate penetration of ciprofloxacin into prostate tissue after administration of a ciprofloxacin 1000 mg extended-release formulation prior to TRNBP.
  
  
  METHODS
  The study enrolled 13 men aged 45-78 years scheduled for TRNBP. They received a single, 1000 mg, extended-release tablet of ciprofloxacin at about 3 hours or at about 1 hour prior to the scheduled biopsy time. Blood and urine samples were taken just prior to the biopsy procedure, and prostate tissue samples after all needle biopsy specimens required for diagnostic purposes had been obtained, for determination of ciprofloxacin concentrations. Population data from a previous crossover study of 25 healthy male volunteers was used to model the prostate tissue concentrations for extended-release ciprofloxacin up to 24 hours after administration. These data were used to predict the normal range data for the current study.
  
  
  RESULTS
  The mean sampling time in the 1-hour group was 1.47 hours (range, 1.25-1.75 hours) and in the 3-hour group was 3.27 hours (range, 3.03-3.42 hours) after ciprofloxacin dosing. The mean concentrations of ciprofloxacin at 1 hour and 3 hours were 4.75 +/- 1.33 microg/g and 4.29 +/- 1.61 microg/g in prostate tissue, 2.11 +/- 1.00 mg/L and 3.08 +/- 1.44 mg/L in serum, and 126.2 +/- 141.7 mg/L and 803.3 +/- 596.3 mg/L in urine. The mean prostate : serum ciprofloxacin concentration ratio was 1.9 : 1 for the 1-hour group and 1.6 : 1 for the 3-hour group. The measured concentrations of ciprofloxacin in prostate tissue fell within the range modelled from the pharmacokinetic data from the 25 healthy, male subjects. No drug-related adverse events were reported.
  
  
  CONCLUSIONS
  Extended-release ciprofloxacin is well tolerated and penetrates effectively into prostate tissue. Tissue levels of ciprofloxacin are similar whether the extended-release ciprofloxacin is administered 1 hour or 3 hours before TRNBP, indicating that tissue levels are maintained for several hours after administration. PK modelling as used in this trial is suitable to prospectively outline clinical designs. Further investigation of single-dose, extended-release ciprofloxacin as prophylaxis for TRNBP is warranted.
authors.affiliation: University of Colorado, Denver, CO, USA.
authors.forename: J
authors.initials: J
authors.lastname: Lugg
authors.forename: J
authors.initials: J
authors.lastname: Lettieri
authors.forename: H
authors.initials: H
authors.lastname: Stass
authors.forename: V
authors.initials: V
authors.lastname: Agarwal
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019072:Antibiotic Prophylaxis; D044963:Biopsy, Fine-Needle; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003692:Delayed-Action Preparations; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D002939:Ciprofloxacin