High-Dose Ciprofloxacin in the Treatment of a Renal Cyst Infection

OBJECTIVE: To report a case of renal cyst infection successfully treated with ciprofloxacin. CASE SUMMARY: The clinical course of a 33-year-old woman with radiologic and symptomatic evidence of a renal cyst infection continued to worsen after 7 days of apparently adequate antibiotic therapy for Escherichia coli isolated from her urine. Antibiotic therapy with intravenous ciprofloxacin 600 mg every 12 hours was administered for 7 days and then given as oral therapy (750 mg q12h) for another 14 days. The patient's clinical condition rapidly improved on ciprofloxacin and follow-up 28 days later showed no evidence of infection. DISCUSSION: Renal cyst infections are a serious complication of polycystic kidney disease and are often refractory to standard antimicrobial therapy. Ciprofloxacin has the chemical properties and antimicrobial activity needed to treat these infections. Previously reported concentrations of ciprofloxacin in renal cyst fluid are therapeutic for the common pathogens associated with renal cyst infections. CONCLUSIONS: Ciprofloxacin appears to be a safe and effective option for treating renal cyst infections. Further controlled studies evaluating its clinical efficacy are warranted.