Rifampin provides new way to treat latent tuberculosis

May 20 2008

A new way to treat patients with latent tuberculosis (TB), who are infected with TB but without symptoms, can effectively treat it in less than half the time and at a lower cost than the current standard treatment, according to researchers who conducted a multi-center, randomized controlled trial. The results will be presented at the American Thoracic Society's 2008 International Conference in Toronto on Tuesday, May 20.

"We found that using a therapy of four months of Rifampin instead of the current nine months of Isoniazid costs significantly less for the healthcare system," said lead analyst, Anne Aspler, M.Sc., of the Respiratory Epidemiology & Clinical Research Unit at McGill University's Montreal Chest Institute. "Overall, Rifampin costs about $484 less per patient treated, which, if we assume that four months of Rifampin has at least equal efficacy to nine months of Isoniazid, represents an added savings to the health system of more than $10,000 per patient prevented from developing TB disease. And because of improvements in compliance, we are actually preventing more cases. This treatment can save money as well as lives."

At present, two billion people are believed to have latent or dormant TB. Of those infected, eight to nine million will develop TB each year, of whom 1.6 million will die. "This is one of the most pressing public health crises in our modern world," said Ms. Aspler.

Rifampin is offered in developing countries, where TB presents the greatest burden, at a subsidized cost through the Global Drug Facility of the World Health Organization. In addition to the cost savings, therapy with Rifampin has the advantage of increased compliance.

"While Isoniazid therapy is 90 percent effective for those who complete it, in reality, fewer than 50 percent do," Ms. Aspler explained. The high attrition rate can have serious public heath effects, not only for the patients who fail to complete therapy, but also for the individuals they may later infect.

According to previous research and program experience in Maryland and New Jersey, a four-month treatment has been shown to improve compliance by 20 to 25 percent. In addition to better completion rates, a four-month course of Rifampin offers the advantages of fewer adverse reactions (fewer serious side effects such as hepatotoxicity or liver damage), and lower costs.

"The next step in research is a major Phase III clinical trial of efficacy-ideally in HIV-infected and non-infected patients and in low-income settings where tuberculosis is the leading cause of death in people living with HIV," said Ms. Aspler.