Tuberculosis is an ongoing problem, and unfortunately, new strains are emerging that don’t respond to the standard treatments. This is by no means a one-sided arms race, and medical researchers are striking back with newer approaches that may break through the resistance.
Generally, tuberculosis is treated with either a drug called isoniazid or with a combination of isoniazid and another drug called rifampin. One in about ten to 12 cases of tuberculosis in the United States is resistant to one or both of those first-line treatments. That means that the particular strain of the virus that causes tuberculosis has evolved protection against those medicines. Often, this is due to doctors or patients failing to properly follow the treatment protocol; however, once a resistant strain develops, it can be transmitted like any other, and is as communicable as tuberculosis ordinarily is.
To combat these strains, the U.S. government is offering drug companies certain incentives to develop new and better medications to which the viruses are not resistant. Under a new law, anti-tuberculosis drugs get a fast track for safety and efficacy review. In addition, the patent protection for pharmaceuticals—the period during which the company that did the research and performed the necessary studies has the exclusive right to market the drug—is extended by five years. This is intended to provide an incentive to create more medications for the disease. Already a third pharmaceutical, pyrazinamide, has been added to the standard protocol, and yet a fourth in high-risk populations.
The good news is that tests for resistance, to determine if a particular patient’s disease requires special effort, are getting faster and more accurate. This will allow doctors to stop ineffective—and possibly dangerous—treatments sooner, and move on to ones that are likely to work. In addition, more and more patients are being treated with combinations of drugs, which help prevent further drug resistance from developing. This means current treatments for tuberculosis are likely to remain effective longer.