Use of fluoroquinolones in patients with respiratory infections can delay the diagnosis of TB

In a new study, we systematically reviewed studies that assessed the delay in the diagnosis and treatment of tuberculosis, among patients who received quinolones, compared to those who received non-fluoroquinolone antibiotics.

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Dec 13, 2016

Fluoroquinolones are among the most widely used antibiotics and they are commonly used for the treatment of respiratory tract infections. In addition to doctors prescribing quinolones, these antibiotics are also frequently dispensed over the counter by pharmacists in countries with weak regulation.

Because fluoroquinolones show bactericidal activity against Mycobacterium tuberculosis complex, there is concern that their use can delay the diagnosis of tuberculosis.

We conducted a systematic review and meta-analysis to assess whether empiric treatment with fluoroquinolones delays the diagnosis and treatment of tuberculosis in patients with lower respiratory tract infections. The primary objective was to assess the delay in days in the diagnosis and treatment of tuberculosis, among patients who received fluoroquinolones, compared to those who were treated with non-fluoroquinolone antibiotics.

After a detailed literature search, we found a total of 10 studies (7 retrospective cohort studies and 3 case-control studies). Only one of these studies was from a high TB burden country, South Africa. The most commonly used fluoroquinolones were levofloxacin, gemifloxacin and moxifloxacin. The unweighted average of difference in delay between the fluoroquinolone group and non-fluoroquinolone group was 12.9 days (95% CI 6.1-19.7). When these differences were pooled using a random effects model, the weighted estimate was 10.9 days (95% CI 4.2-17.6). When stratified by acid-fast smear status, the delay was consistently greater in the smear-negative group. Although results are variable across studies, the use of fluoroquinolones in patients with respiratory infections seems to delay the diagnosis of TB by nearly two weeks. So, consistent with the International Standards for TB Care, quinolones should be avoided when tuberculosis is suspected.

Full paper is free access at: Hogan C et al. J Clinical Tuberculosis 2016

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Madhukar Pai

Director, McGill Global Health Programs

I am a Professor and a Canada Research Chair in Epidemiology & Global Health at McGill University, Montreal. I serve as the Director of McGill Global Health Programs, and Director of the McGill International TB Centre. URL:

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