July 24 (HealthDay News) -- Eli Lilly's Forteo (teriparatide injection) has received expanded approval from the U.S. Food and Drug Administration to treat osteoporosis associated with long-term use of glucocorticoid medication, the company said Thursday.

Glucocorticoid therapy is commonly prescribed for inflammatory conditions including rheumatoid arthritis and obstructive lung disease. These drugs are among the most common causes of secondary osteoporosis, which increases users' risk of bone fracture, Lilly said in a news release.

As many as three of every 100 adults over age 50 use this type of medication, Lilly said, and of those, about half will eventually have an osteoporotic bone fracture.

In clinical testing among patients with glucocorticoid-induced osteoporosis, Forteo increased bone mineral density after 18 months of use by an average of 7.2 percent at the spine, 3.6 percent at the hip, and 3.7 percent at the neck, the company said.

The drug should never be used by children and young adults whose bones may still be growing. And in rare cases, users have developed a form of bone cancer called osteosarcoma. It's not known if the drug increased their risk, Lilly said.