A team of Brazilian and US TB experts reported at a meeting of the American Society for Microbiology that adding the drug moxifloxacin to a standard cocktail of antibiotics increased by 17 percent the number of patients who cleared active TB infection from their lungs, to 68 percent from 85 percent.
The new combination drug therapy uses moxifloxacin in the place of an older, more traditional anti-TB drug, ethambutol.
The drug mixture shortened by two months the time needed to cure the highly infectious lung disease, experts reported at a meeting here of the 47th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).
"This is the most compelling evidence in nearly 25 years that a novel antibiotic drug combination works better than the current gold standard at curing active TB infection," said study senior author Richard Chaisson, a professor of medicine, epidemiology and international health at The Johns Hopkins University School of Medicine.
"Beyond the obvious value of healing patients more quickly, a shorter treatment time could also cut down on transmission of the disease to others and make it easier for health care workers worldwide, who are overwhelmed by large numbers of patients, to treat more people and to treat them faster" said Chaisson, who also heads Hopkins's Center for Tuberculosis Research.
He noted that worldwide, nearly nine million new cases of TB are diagnosed each year, and more than one and a half million people die from the disease.
Tuberculosis can be particularly lethal for those with HIV and AIDS. The lung ailment has reached epidemic levels in developing countries with the high HIV infection rates.
The study of more than 170 TB-infected men and women in Rio de Janeiro, Brazil found after two months of combination therapy that patients who had taken moxifloxacin were significantly less likely have evidence of live TB bacteria in their bodies that patients on traditional ethambutol therapy.
Conventional TB therapy usually involves a six-month course of antibiotics, typically about four drugs in combination -- a treatment which cures about 95 percent of patients on average.
Substituting moxifloxacin not only appears to be faster and more effective, but also is also less expensive -- a major consideration for TB treatment in developing countries.
The shorter course of medication also increases the likelihood that patients will complete their therapy, thereby risking contracting and spreading drug-resistant strains of TB.