Fluoroquinolones: a new treatment for tuberculosis?

The fluoroquinolones have secured an important place in the management of bacterial infection, they are well absorbed orally, are found in respiratory secretions in higher concentrations than in serum and are concentrated inside macrophages. The agents are well tolerated and have an excellent safety record in long-term therapy. No new antituberculosis agents have been developed since the introduction of rifampicin into clinical use, so fluoroquinolones have been investigated for potential efficacy in tuberculosis. In vitro studies have shown that they are active against Mycobacterium tuberculosis at achievable concentrations. Treatment studies in mice have demonstrated efficacy. Few clinical studies have been performed in humans, but ciprofloxacin has demonstrated significant early bactericidal activity. Regimens including a fluoroquinolone have been comparable to other standard regimens, although the outcome in human immunodeficiency virus (HIV) seropositive patients was significantly poorer. There is still insufficient clinical data to use fluoroquinolones in first-line treatment of tuberculosis, but they may find a role in the management of multidrug-resistant infections or in patients with adverse reactions to other agents.