Pain drug could kill drug-resistant TB

Weill Cornell Medical College researchers have found that an off-patent anti-inflammatory drug can kill replicating and non-replicating drug-resistant tuberculosis in a laboratory.

The new therapy, which costs approximately two cents per daily dose in developing countries, could help the more than 500,000 people worldwide affected by drug-resistant TB.

Researchers, however, are concerned that oxyphenbutazone, a drug that was prescribed for arthritis-like pain in the early 1950s, will never be tested in clinical trials.

"It is difficult today to launch clinical studies on a medication that is so outdated in the United States, that it is mainly used here in veterinary medicine to ease pain," Carl Nathan, the senior author of the study, said. "No drug firm will pay for clinical trials if they don't expect to make a profit on the agent. And that would be the case for an off-patent drug that people can buy over the counter for pain in most of the world."

The drug, known under the trademark name of Tandearil, does have established toxicities, but the toxicities appear to be less frequent than the major side-effects of current TB drug regimens.

Researchers tested 5,600 drugs against tuberculosis bacteria in the ideal conditions for its growth of low oxygen, mild acidity, fat instead of sugar and a small amount of nitric oxide. The researchers found that oxyphenbutazone causes the bacterium to remain dormant, become defenseless and eventually die.

"This agent might help save lives if there was a way to test it in TB patients," Nathan said.