The risk of infectious and inflammatory complications after PNL is based on presence of microorganisms in the form of biofilms inside the stone. Destruction of stones during surgery or lithotripsy may be a trigger for the growth of microorganisms that are integrated into the biofilms, and the migration of bacteria and their toxins in the blood flow under pressure of irrigation fluid can cause septic complications. The danger of infectious and inflammatory complications after percutaneous interventions for kidney stones requires a search for specific antibiotics for antimicrobial prophylaxis and efficient modes of their administration. The results of a comparative study of pharmacokinetic parameters of ciprofloxacin, and the effectiveness of two modes of administration (bolus dosing and prolonged intravenous administration) at a dose of 1000 mg are presented.