An inexpensive, over-the-counter pain reliever can kill the bacteria that cause tuberculosis (TB)—even the drug-resistant varieties—according to a new study published online in the Proceedings of the National Academy of Science this week (September 10), yet it’s not a promising candidate for drug trials.
Researchers at the Weill Cornell Medical College designed a screen to find drugs that target dormant TB bacteria—triggered by certain lung conditions, dormancy is a key strategy Mycobacterium tuberculosis uses to evade drugs and cause lethal infections in nearly 1.5 billion people per year. The researchers found that the anti-inflammatory drug oxyphenbutazone, developed to treat arthritis in the 1970s, is activated in lung conditions that induce dormancy, and can kill dormant, active, and even resistant bacteria.
But the researchers are skeptical the drug will ever be given to a TB patient. “It is difficult today to launch clinical studies on a medication that is so outdated in the United States,” Weill microbiology professor and the senior author Carl Nathan said in a press release. “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.”
Another hurdle for the drug is that it can’t be tested in mouse models because the animals metabolize the drug to an inactive form faster than humans do—too fast to treat TB infection.
“This makes testing the drug for TB use in humans problematic since the FDA requires preclinical animal testing studies for safety and efficacy,” Nathan said in the release. "Yet there is a long track record of oxyphenbutazone's relatively safe use in hundreds of thousands of people over decades."