New treatment for latent tuberculosis

MONTREAL, Jan. 23 (UPI) -- A four-month treatment with the drug rifampin is better tolerated for tuberculosis than the nine-month treatment of isoniazid, Canadian researchers said.

Dr. Dick Menzies of the McGill University said patients who are infected with the latent form of TB show no symptoms and are not contagious, yet they pose the biggest challenge when it comes to controlling the disease.

Patients who currently receive a diagnosis of latent TB are treated for nine months with daily doses of isoniazid; although effective, this treatment is very long and has major side effects on the liver, Menzies said.

"Our results show that a four-month treatment with rifampin is better tolerated than the traditional nine-month treatment with a drug called isoniazid," Menzies said in a statement. "The side effects with rifampin are much less frequent, particularly liver toxicity -- which is the most serious risk of the traditional therapy with isoniazid. In addition patients are much more likely to complete this treatment -- another big drawback to the nine month standard therapy."

The study, published in the Annals of Internal Medicine, was conducted on 847 patients in Canada, Brazil and Saudi Arabia and the results can be generalized to a very broad population, Menzies said.

More in-depth studies will be necessary to test the effectiveness of this medication against latent TB, but the study researchers said this treatment option appears promising.