After two months of combination therapy, cultured sputum samples from patients taking moxifloxacin were significantly less likely to grow TB bacteria than samples from those on traditional ethambutol therapy. The time to clear the infectious organism from sputum was also significantly shorter in the moxifloxacin group.
Conventional TB therapy prescribes a mix of antibiotics, typically four, given in view of a caregiver and taken together for six months. Commonly known by its acronym DOTS, short for Directly Observed Therapy Short-Course, the treatment cures on average 95 percent of patients who finish taking their medications as originally prescribed.
But experts say the lengthy treatment period has proven a problem for patients, who sometimes miss taking their drugs on time, minimizing the therapys effectiveness and increasing the risk that drug-resistant strains will develop.
History, says Chaisson, demonstrates that shorter regimens boost drug compliance and cure rates, often by as much as 50 percent. In the 1950s, TB treatment lasted from 18 to 24 months, and nearly a quarter of patients failed to complete therapy. It was not until new drugs appeared in the 1970s and 1980s, when treatment times were shortened to an average of six months, that cure rates shot up.
In the latest study, all participants were given a standard combination of three antibiotic pills isoniazid, rifampin, and pyrazinaminde and then randomly assigned to receive a fourth pill, either moxifloxacin or ethambutol. Moxifloxacin, approved for use in the United States since 1999 as a treatment for pneumonia, is not currently approved as a treatment for TB. However
|Contact: David March|
Johns Hopkins Medical Institutions