Oral ofloxacin for infections caused by bacteria resistant to oral antimicrobial agents.

ABSTRACT

We conducted an open trial of oral ofloxacin, 400 mg q 12 hr, in the treatment of infections caused by Pseudomonas aeruginosa and other bacteria resistant to traditional oral antibiotics. There were 53 evaluable subjects, 30 having infection of the skin/skin structure, 13 of the respiratory tract, six of bone, and four complicated infections of the genitourinary tract. Most subjects (72%) had previously failed a course of antibiotic therapy for their infections. Ofloxacin therapy was administered an average of 45 days per patient, and was well tolerated. Clinical success was observed in 40 (74%) subjects, with failure in 13 (26%). Responses ranged from 50% success for six lower respiratory tract infections to 100% success for six cases of osteomyelitis. There were 28 P. aeruginosa with 22 Gram-positive and 24 other Gram-negative infections. Of 28 cases in which P. aeruginosa was implicated as a pathogen, 19 (68%) were successfully treated with ofloxacin therapy. Overall, 63 (85%) of 74 pathogens were eradicated. Of the 11 persistent organisms, five were P. aeruginosa in which resistance to ofloxacin emerged during therapy. Our data imply ofloxacin to be effective for infections due to ofloxacin-susceptible organisms other than P. aeruginosa; for this pathogen, ofloxacin therapy is associated with a high degree of failure. If ofloxacin is used for infection due to P. aeruginosa, microbiologic surveillance is necessary for cases that either fail to respond or relapse clinically.