Lung tissue concentrations of ciprofloxacin following intravenous administration in patients.

Serum and corresponding lung tissue concentrations of ciprofloxacin (Ciprobay) were investigated in 25 patients undergoing open lung surgery for pulmonary malignancies. Drug levels were measured at various times (50-240 min) after completion of a single i.v. dose of 200 mg by bioassay and HPLC. Lung tissue concentrations peaked within one hour after dosing (bioassay: 3.2 micrograms/g, HPLC: 4.5 micrograms/g). Tissue levels exceeded corresponding serum level 3- to 4fold throughout the observation period. The results demonstrate excellent penetration properties of this new antimicrobial compound into lung tissue. Ciprofloxacin was concentrated in the lung and thus by far exceeded known minimum inhibitory concentrations for most nosocomial respiratory pathogens.