Clinical efficacy of ciprofloxacin in lower respiratory tract infections.

The sputum pharmacokinetics and clinical efficacy of ciprofloxacin in lower respiratory tract infections is reviewed. Following intravenous administration, ciprofloxacin penetrates rapidly into bronchial tissue; the elimination half life is between 3 and 4 h and a dose dependency is seen. Following oral intake, the time to reach maximal concentrations is approximately two hours and after a dose of 750 mg the concentration may reach 1.7 mg/l in patients without cystic fibrosis and range from 0.5 to 3.4 mg/l in cystic fibrosis patients. Coadministration of ciprofloxacin increases serum levels and decreases total body clearance of theophylline. In controlled comparative clinical trials, ciprofloxacin has been found to have similar clinical efficacy as amoxycillin, ampicillin, cefalexin, doxycycline, co-trimoxazole, imipenem-cilastatin and ceftazidime for the treatment of a range of lower respiratory tract infections. Ciprofloxacin has been found to be superior in clinical efficacy to cefaclor. Experimental animal models suggest a role for ciprofloxacin in infections caused by Legionella pneumophila and Mycoplasma pneumoniae. The clinical and bacteriological efficacy of ciprofloxacin is less pronounced in lung infections caused by Pseudomonas aeruginosa, but is comparable to the combination of beta-lactams and aminoglycosides. Development of resistance is frequently observed during ciprofloxacin treatment of Ps. aeruginosa. Because of the availability of other oral and effective agents, ciprofloxacin is not recommended for empirical treatment of community acquired lower respiratory infections, but should be reserved for infections caused by multiply resistant organisms.