WASHINGTON » The Food and Drug Administration says it has approved a Johnson & Johnson tuberculosis drug that is the first new medicine to fight the deadly infection in more than four decades.

The agency approved J&J’s pill, Sirturo, for use with other older drugs to fight hard-to-treat tuberculosis.

Sirturo is the first medicine specifically designed for treating multi-drug-resistant tuberculosis. That’s an increasingly common form of the disease that cannot be treated with at least two of the four primary antibiotics used to treat tuberculosis.

The standard drugs used to fight the disease were developed in the 1950s and 1960s.

Roughly one-third of the world’s population is estimated to be infected with the bacteria causing tuberculosis.