Two drug combination shows effectiveness in fighting TB

A combination of two drugs already approved by the U.S. Food and Drug Administration shows promise in treating tuberculosis patients.

Dr. John Blanchard, a professor of biochemistry at the Albert Einstein School of Medicine of Yeshiva University, recently said that treatment with the antibiotic meropenem, in addition to the medication clavulanate, could offer new prospects against the drug-resistant XDR and MDR strains of the disease, according to

"We've tested this combination against laboratory strains of Mtb, XDR and MDR strains from patients," Blanchard said, reports. "In all cases, the combination doesn't just slow down growth - it kills the bacterium in laboratory tests."

Blanchard made the comments at the 243rd National Meeting & Exposition of the American Chemical Society.

"As you can well imagine, after 40 or 45 years of people being treated with the same drugs, what's happening is that the bacterium is developing resistance to those drugs," Blanchard said, according to "Some forms, or strains, are resistant to many drugs (MDR, or multidrug-resistant), and some are resistant to almost all known antibiotics (XDR, or extensively drug-resistant). There's nothing currently available that he can use to treat these patients."

Blanchard and his team found the combination during a study of a class of enzyme associated with TB known as beta-lactamase. Beta-lactamase destroys many kinds of antibiotics, including meropenem.

Blanchard and his colleagues found that the drug clavulanate could stop the enzyme and clear the way for the antibiotics to work. They found the best combination in their research included both meropenem and clavulanate delivered by injection.

The combination would also have the added benefit of cutting the number of drugs taken by TB patients in half, compared to the current standard treatment. Meropenem is currently considered to be expensive, but the price is expected to fall later this year when generic forms become available.

Clinical studies in the United States have yet to be done on the two drug treatment, but results from Europe are promising. The Albert Einstein School of Medicine recently filed a patent application on the combination in order to encourage drug companies to become involved with clinical development.