ATLANTA - You're in a staff meeting of 150 people and all of a sudden the boss does what she's never done before -- asks everyone to get up and introduce himself or herself.

You're terrified. When it's your turn, your voice quivers.

Or you're so afraid of flying that even the sight of a big jet up close sets your heart to racing.

Or the mere thought of stepping into an elevator makes you huff up eight flights of stairs.

Most likely, with any of these symptoms, you're one of 40 million Americans with an often debilitating anxiety disorder that could make it tougher for you to climb the corporate ladder.

But here's some good news: An Atlanta biotechnology company is planning to market a drug within a few years that's been shown to extinguish such fears, or at least make them easier to handle.

The capsule has had Food and Drug Administration approval for more than 50 years as a treatment for chronic tuberculosis. But recent research has found that it does something else -- it "extinguishes fear" if taken before only a few sessions with a therapist, and the response comes faster and seems to last.

Harold Shlevin, chief executive of the Tikvah Therapeutics biotechnology firm, says that when the drug D-cycloserine hits pharmacy shelves as an aid in the treatment of anxiety disorders, it could bring in at least $1 billion a year in the United States.

Dr. Russell Ellison, an executive with the New York-based Paramount BioSciences venture capital firm, says 85 percent of people with anxiety disorders will see a doctor once a year, and D-cycloserine appeals to patients because it doesn't require prolonged psychotherapy sessions. Rather, several studies have shown that taking a single dose of the drug before just three or four sessions of exposure therapy can "teach" social phobics that they had nothing to fear after all.

Exposure therapy can take several forms. Often, therapists take patients on elevators or on airplane flights to teach them that their fears are irrational. This often takes a lot of time and is costly.

With D-cycloserine, also called DCS, the cost would be much lower.

The drug is being used now in studies at Emory University on war veterans with post-traumatic stress disorder.

"It works pretty well," said Dr. Barbara Rothbaum, director of the Trauma and Anxiety Recovery Program at Emory's School of Medicine. "We're going to see untold thousands of Americans from Iraq and Afghanistan with PTSD in coming years."

DCS does nothing "in and of itself," but together with exposure therapy, it teaches the brain not to be fearful in previously terrifying situations, she says.

"This could be huge," said Rothbaum, who stands to gain "a little" from her stake in Virtually Better Inc., the Decatur, Ga., firm that creates many virtual environments, such as elevators, jet planes and combat. "Think of people who can't go up on ladders or are afraid of driving over Spaghetti Junction."

Right now, Paramount owns 90 percent of Tikvah, Shlevin owns 7 percent and other investors in Tikvah own the rest.