Sale of GlaxoSmithKline's (NYSE:GSK) diabetes drug Avandia, restricted in the U.S. and banned in Europe after concerns emerged that it might cause heart attacks, could now   be relaxed if an FDA panel recommendation is approved.

Thirteen members out of a 26-member expert advisory panel to the Food and Drug Administration, or FDA, consisting of outside health experts voted, on Thursday, in favor of modifying the restrictions on the marketing of Avandia.

"In general, this drug doesn't look any different than any other diabetes drug," Dr. William Hiatt, a cardiologist from the University of Colorado, and a panel member who backed lifting restrictions, told Reuters.

Avandia, once the best-selling diabetes drug in the world, was taken off drugstore shelves in the U.S. and was banned completely in Europe and some Asian countries, including India, on concerns over cardiovascular safety.

The regulations on Avandia restricted its availability to patients, as it was sold only through specially registered pharmacies. The patients also had to sign informed-consent forms before taking the drug.

The panel’s decision was based on re-examination of data from a clinical trial, which an earlier panel, in 2010, had expressed concerns about. The latest independent analysis  of Avandia’s original clinical trial, by Duke University researchers, suggested that there is no substantial evidence to prove the drug increased the risk of a heart attack.

This two-day advisory panel’s decision -- to relax or eliminate current restrictions -- is a recommendation to the FDA and is not binding.

"We continue to believe that Avandia is a safe and effective treatment option for type 2 diabetes when used for the appropriate patient and in accordance with labeling," Dr. James Shannon, GlaxoSmithKline's chief medical officer, said in a statement. A Reuters report said that Glaxo no longer has plans to promote Avandia.

Avandia, or its generic version Rosiglitazone, works as an insulin sensitizer, and generated annual sales worth $3.2 billion before the restrictions took hold. And, the number of patients who use Avandia in the U.S. has come down to 3,000 from about 120,000 in the same period, according to a Reuters report.