A team of tuberculosis (TB) experts have evidence that substituting the antibiotic moxifloxacin in the regimen of drugs used to treat the highly contagious form of lung disease could dramatically shorten the time needed to cure the illness from six months to four.
Adding moxifloxacin to a standard combination of other antibiotics increased by 17 percent the number of patients who cleared active infections from their lungs (raising cure rates from 68 percent to 85 percent), after just two months of therapy, and when compared to patients taking the standard combination with another, older antibiotic, ethambutol.
The new study of more than 170 men and women â€“ all with active TB â€“ showed that combination drug therapy with moxifloxacin was more potent than combination therapy with an older, more traditional anti-TB drug, ethambutol. Symptoms of active TB include fever, cough, night sweats and weight loss.
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 therapyâ€™s effectiveness and increasing the risk that drug-resistant strains will develop.
In the latest study, all participants were given a standard combination of three antibiotic pills â€“ isoniazid, rifampin, and pyrazinaminde â€“ 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, ethambutol has been approved to treat TB since 1962.