Cinoxacin in urinary tract infections. Theoretical and practical considerations

Area of Science:

• Pharmacology
• Urology
• Veterinary Medicine

Background:

• Cinoxacin is an antibiotic used for urinary tract infections.
• Understanding drug distribution in prostatic tissue is crucial for effective treatment.

Purpose of the Study:

• To determine cinoxacin concentrations in canine prostatic tissue, secretions, and interstitial fluid.
• To evaluate cinoxacin concentrations in human prostatic tissue.
• To assess cinoxacin's pharmacokinetic profile in humans with varying renal function.

Main Methods:

• Constant infusion experiments in dogs to measure cinoxacin levels in serum, prostatic tissue, secretion, and interstitial fluid.
• Administration of single or multiple 500 mg doses of cinoxacin to human subjects.
• Measurement of cinoxacin serum half-life in patients with normal and impaired renal function.

Main Results:

• In dogs, cinoxacin concentrations were consistently lower in prostatic tissue, secretion, and interstitial fluid compared to serum.
• Canine urethral and vaginal secretions showed cinoxacin concentrations approximately one-third to one-fourth of serum levels.
• Human prostatic tissue cinoxacin concentrations after 500 mg doses were within the minimum inhibitory concentration range for common urinary tract pathogens.
• Cinoxacin half-life was 2.7 hours in normal renal function and 8.5 hours in impaired renal function.
• Little to no drug accumulation was observed in patients with impaired renal function over seven days.

Conclusions:

• Cinoxacin exhibits limited distribution into canine prostatic tissue and secretions.
• Achieved cinoxacin concentrations in human prostatic tissue are therapeutically relevant for treating urinary tract infections.
• Cinoxacin's elimination is prolonged in patients with renal impairment, but accumulation is minimal with standard dosing regimens.