Empirical treatment with a fluoroquinolone delays the treatment for tuberculosis and is associated with a poor prognosis in endemic areas

Background: A study was conducted to evaluate the effect of the empirical use of fluoroquinolones on the timing of antituberculous treatment and the outcome of patients with tuberculosis in an endemic area. Methods: All patients with culture confirmed tuberculosis aged >= 14 years diagnosed between July 2002 and December 2003 were included and their medical records were reviewed. Results: Seventy nine (14.4%) of the 548 tuberculosis patients identified received a fluoroquinolone (FQ group), 218 received a non-fluoroquinolone antibiotic (AB group), and 251 received no antibiotics before antituberculous treatment. Fifty two (65.8%) experienced clinical improvement after fluoroquinolone use. In the FQ group the median interval from the initial visit to starting antituberculous treatment was longer than in the AB group and in those who received no antibiotics ( 41 v 16 v 7 days), and the prognosis was worse ( hazard ratio 6.88 (95% CI 1.84 to 25.72)). More patients in the FQ and AB groups were aged > 65 years (53.2% and 61.0% v 31.5%), had underlying disease ( 53.2% and 46.8% v 34.3%), and were hypoalbuminaemic (67.2% and 64.9% v 35.1%). Of the nine mycobacterial isolates obtained after fluoroquinolone use from nine patients whose initial isolates were susceptible to ofloxacin, one (11.1%) was resistant to ofloxacin ( after fluoroquinolone use for 7 days). Independent factors for a poor prognosis included empirical fluoroquinolone use, age > 65, underlying disease, hypoalbuminaemia, and lack of early antituberculous treatment. Conclusions: 14.4% of our patients with tuberculosis received a fluoroquinolone before the diagnosis. With a 34 day delay in antituberculous treatment and more frequent coexistence of underlying disease and hypoalbuminaemia, empirical fluoroquinolone treatment was associated with a poor outcome. Mycobacterium tuberculosis isolates could obtain ofloxacin resistance within 1 week.