Off-patent pain drug could kill resistant TB

Researchers at Weill Cornell Medical College have found that an off-patent anti-inflammatory medicine can kill both replicating and non-replicating drug resistant tuberculosis in the laboratory, a feat currently only few approved TB drugs can do.

Their findings point to a potential new therapy for the more than 500,000 people worldwide whose TB has become resistant to standard drug treatments.

But researchers worry that the effective drug, oxyphenbutazone, may never be tested in TB clinical trials.

The research led by Dr Carl Nathan found what they call the "completely surprising" ability of 'oxyphenbutazone' to kill drug resistant TB after testing thousands of approved drugs against the bacteria.

This repurposing of agents already on the market can lead to quicker testing for new uses.

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

Oxyphenbutazone went on the market as a patented drug for arthritis-like pain in the early 1950s, and lost its patent and market dominance by the 1970s.

"It is difficult today to launch clinical studies on a medication that is so outdated in the United States, that it is mainly used here in veterinary medicine to ease pain," said Nathan.

He added that oxyphenbutazone, best known under the trademark name of Tandearil, does have some established toxicities, "and is not a drug you should take for aches and pains if a safer alternative is available."

But the drug's major toxicities appear to be less frequent than the major side-effects of the drug regimens that are currently used to treat TB, he noted.

The study was published in the journal 'PNAS'.