NEW YORK (Reuters Health) – The results of a new study suggest that tuberculosis may be cured faster by adding moxifloxacin to a standard TB treatment protocol than by adding ethambutol, according to a report in the April 4th issue of The Lancet.

In the study, conducted by Dr. Richard E. Chaisson and colleagues, the negative culture rate in moxifloxacin-treated patients at 8 weeks was 80% versus 63% for subjects given ethambutol (p = 0.03).

At present, drug-susceptible tuberculosis is treated with a 6-month course of antibiotics; however, many patients do not complete the full course. Use of agents that can shorten treatment can help reduce the risk of disease recurrence and prevent deaths due to inadequate therapy, Dr. Chaisson, from Johns Hopkins University School of Medicine, Baltimore, and colleagues note.

Moxifloxacin is a fourth generation fluoroquinolone that has been shown to be highly active against Mycobacterium tuberculosis in vitro. Further research has indicated that it has additive effects to currently used anti-tuberculosis agents, such as isoniazid.

The current study involved 170 subjects who were randomized to receive moxifloxacin (400 mg) or ethambutol (15 to 20 mg/kg) 5 days per week for 8 weeks in combination with isoniazid, rifampin, and pyrazinamide. The main outcome measure was the percentage of subjects with negative sputum cultures at 8 weeks.

As noted, a significantly greater percentage of moxifloxacin-treated patients than ethambutol-treated patients were culture-negative at 8 weeks.

Eight adverse events occurred in each group, but just one, a grade 3 skin reaction in the ethambutol group, was judged to be related to the study drug.

“The results of our study support the undertaking of clinical trials to assess whether shorter courses of moxifloxacin-containing regimens can cure tuberculosis as well as or better than the current 6-month regimen. Such trials are underway and their results are eagerly awaited,” the authors conclude.

Reference:
Lancet 2009;373:1183-1189.