April 13, 2011

New Way to Treat TB

(Ivanhoe Newswire) -- In patients with newly-diagnosed tuberculosis (TB), use of a combined four-drug, fixed-dose regimen was found to have comparable outcomes to drugs administered separately, according to a new study.

"Despite the availability of a highly effective 6-month chemotherapy regimen, worldwide control of tuberculosis is severely impeded by poor treatment completion rates that threaten the emergence of multidrug resistance," according to background information in the article. "Fixed-dose combinations (FDCs) of drugs have been advocated as a way of preventing the emergence of drug resistance attributable to inappropriate drug intake. In addition, they can reduce the risk of incorrect dosage, simplify drug procurement, and aid in ensuring adherence."

Christian Lienhardt, M.D., M.Sc., Ph.D., of the World Health Organization, Geneva, Switzerland and colleagues conducted a multicenter randomized controlled trial to evaluate the efficacy and safety of a four-drug FDC for the treatment of tuberculosis. The study included 1,585 adult patients with newly-diagnosed, smear-positive pulmonary tuberculosis. Patients were randomized to receive daily treatment with four drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) given as an FDC (n = 798 patients) or separately (n = 787) in the eight-week intensive phase of treatment.

The FDC was assessed for noninferiority (no worse than the separate drug regimen) via several measures.

The researchers found that 18 months after the start of treatment, 93.9 percent of patients in the FDC group vs. 94.6 percent in the separate-drugs group had a favorable outcome. In two different models of a modified intention to treat analysis, the researchers found that 83.3 percent of patients in the FDC group had a favorable outcome compared with 84.8 percent in the separate-drugs group.

"The results of this trial show, using a strict definition of noninferiority, that a four-drug FDC regimen may be noninferior to a regimen of separately administered drugs in terms of efficacy for treatment of tuberculosis," the researchers were quoted as saying. They add that one of the main advantages of FDCs is that patients have to take considerably fewer pills (3-4 instead of 9-16 per day in the intensive phase), thus making treatment easier, aiding adherence, and potentially eliminating the risk of developing drug resistance.

"For efficient tuberculosis control worldwide, it is essential that quality-assured FDCs are made available. While new regimens or drugs are being developed for the treatment of tuberculosis, it is essential that strategies are developed for their introduction in national tuberculosis control programs, which includes the protection of these new drugs within established and quality-assured FDCs," the researchers were quoted as saying.

SOURCE: JAMA, published online April 13, 2011