While fluoroquinolones previously were considered medications of choice in the empiric treatment of uncomplicated urinary tract infection, the IDSA now recommends against using these agents as medications of choice for the treatment of this infection in women. Fluoroquinolones are not first-line choices for the treatment of acute bacterial sinusitis; however, the respiratory fluoroquinolones (gemifloxacin, levofloxacin, moxifloxacin) are recommended by the IDSA for high-risk patients with community-acquired pneumonia. The reason for this recommendation is the fact that the respiratory fluoroquinolones are exquisitely active against the most common bacterial pathogens, including S pneumoniae, H influenzae, and the “atypical pathogens,” eg, Legionella, Mycoplasma, and Chlamydophila pneumoniae. Among hospitalized patients receiving these fluoroquinolones for the treatment of community-acquired pneumonia, oral and intravenous administration are similar in terms of in-hospital mortality, intensive care unit (ICU) admission, antibiotic escalation, length of stay, and cost.
Because quinolones have excellent penetration into prostatic secretions, they are effective in treating both acute and chronic bacterial prostatitis associated with susceptible pathogens.
Quinolones are approved for treatment of certain sexually transmitted diseases. Ofloxacin, 300 mg orally twice daily for 7 days, is as effective as doxycycline, 100 mg orally twice daily for 7 days, for the therapy of C trachomatis cervicitis, urethritis, and proctitis. It is also effective for nongonococcal urethritis caused by U urealyticum. Ciprofloxacin is not effective for the therapy of chlamydial infections or nongonococcal urethritis. The increased prevalence of quinolone-resistant gonococci in the United States has resulted in the Centers for Disease Control and Prevention (CDC) no longer recommending these agents in the treatment of this disease. Intramuscular ceftriaxone is the one CDC-recommended primary therapeutic option for the treatment of Neisseria gonorrhoeae.
Pelvic inflammatory disease is usually caused by C trachomatis, N gonorrhoeae, Enterobacteriaceae, or anaerobes. Considering the high rate of fluoroquinolone-resistant N gonorrhoeae, regimens that include a quinolone are no longer recommended. Patients with severe cephalosporin allergy and close follow-up for cure can be given certain fluoroquinolones for 14 days (levofloxacin 500 mg orally once daily, ofloxacin 400 mg twice daily, or moxifloxacin 400 mg orally once daily) with metronidazole for 14 days (500 mg orally twice daily). Epididymitis in men younger than 35 years is caused most commonly by Chlamydia and the gonococcus. While intramuscular ceftriaxone plus oral doxycycline is the regimen of choice for acute epididymitis, levofloxacin, 500 mg orally once daily (or ofloxacin, 300 mg orally twice daily) for 10 days, can be used. Therapy including levofloxacin or ofloxacin is possible if the infection is most likely caused by enteric organisms and gonorrhea has been ruled out by laboratory testing. Fluoroquinolones have been used successfully to treat complicated skin and soft-tissue infections and osteomyelitis caused by gram-negative organisms. Ciprofloxacin, 500–750 mg orally twice daily for at least 6 weeks, has been effective therapy for malignant otitis externa.
Quinolones are among the few oral agents active against Campylobacter; however, resistance has been steadily increasing, and macrolides are significantly more active. In addition, they are active against the other major bacterial pathogens associated with diarrhea (Salmonella, Shigella, toxigenic E coli). Consequently, they have been used for the therapy of traveler’s diarrhea as well as domestically acquired acute diarrhea. Norfloxacin, ciprofloxacin, and ofloxacin may be effective in eradicating the chronic carrier state of Salmonella when therapy is continued for 4–6 weeks.
Ciprofloxacin, similar to rifampin, has been used to eradicate meningococci from the nasopharynx of carriers.
Fluoroquinolones are effective for prophylaxis against gram-negative infections in the neutropenic patient, and intravenous ciprofloxacin in combination with beta-lactam antibiotics has been used successfully to treat febrile neutropenia.
As discussed previously, gemifloxacin, levofloxacin, and moxifloxacin, the “respiratory fluoroquinolones,” are useful in the treatment of community-acquired pneumonia. However, their broad aerobic gram-negative spectrum and the rapid emergence of resistance suggests that they should be reserved for the treatment of refractory infections or high-risk patients, including those with comorbidities or with recent receipt of beta-lactam antibacterials. One setting in which ciprofloxacin is indicated for the therapy of lower respiratory tract infections is in cystic fibrosis, in which P aeruginosa is the predominant pathogen. However, the increasing rate of resistance to ciprofloxacin and levofloxacin has diminished their utility for this indication.