Ciprofloxacin therapy of respiratory tract infection with Pseudomonas aeruginosa.

Forty-two patients with respiratory tract infection caused by Pseudomonas aeruginosa were treated with 500 mg ciprofloxacin administered orally twice daily. Pseudomonas aeruginosa was eradicated in 22 patients but recurred in eight patients. Clinical improvement or resolution was noted in 37 patients (88%). Eradication and cure rates were highest in patients without permanent risk factors, and in patients with hospital-acquired infection. New colonization during treatment was noted in 14 patients (33%), but no superinfection occurred. In persisting strains of Pseudomonas aeruginosa the in vitro sensitivity to ciprofloxacin decreased significantly during therapy.