New diabetes drugs should be thoroughly studied for potential heart risks before being brought to the market, U.S. Food and Drug Administration advisers said on Wednesday.

With almost a unanimous vote (14-2), they decided that all drug makers should conduct long-term cardiovascular trials, even if the drugs show no signs of heart problems in initial trials.

The decision comes as cardiovascular risks are the number one killer of diabetics and one year after the FDA was harshly criticized for its handling of the type 2 diabetes drug Avandia (rosioglitazone), of GlaxoSmithKline.

After eight years on the market, the world’s best-selling diabetes pill last year was linked to heart attacks. The FDA requested a black box warning about the increased risk of heart attack in November 2007.

The drug continues to be prescribed to diabetics to lower blood sugar, the main goal of drugs for type 2 diabetes because the FDA concluded the inherent risk of heart attack wasn’t any greater than that associated with other similar medications. The health agency also asked Glaxo to study the issue but results from that trial aren’t expected until 2014.

Now, under the new recommendation of the advisory panel, the companies making diabetes drug must run studies lasting for at least five years to detect heart attacks, strokes and other problems. Many embraced the idea of starting the study before approval and completing it after a drug reaches the market. Currently, the FDA only requires that drugs for type 2 diabetes lower blood sugar, which is believed to protect diabetics from the debilitating side effects of the disease.

However, Dr. Steven Nissen, chairman of the Cleveland Clinic’s department of cardiovascular medicine, told the FDA advisers that the agency should make companies demonstrated that their diabetes drugs do not increase risks of cardiovascular disease before approval, the WSJ reported.

“Merely lowering blood-glucose levels in diabetes is too simplistic. We must reduce the complications of diabetes, including cardiovascular disease,” Dr. Nissen told the panel.

Dr. Nissen and colleague Kathy Wolski, published a study in the New England Journal of Medicine in May last year which found a 43 percent increased risk of heart attack among patients taking Avandia. For their study, they evaluated 42 other studies involving nearly 28,000 patients and compared the 15,560 patients who were using Avandia to the patients who were not using the drug.

However, Dr. Nissen’s recommendation was not entirely embraced, with many saying that the drugs’ side effects might not be known until the drug reaches the market.

“The fallacy here is that we will never know everything we'd like to about a drug before it goes on the market. If we held up drugs until we did know everything a lot of people would die,” Dr. Ray Woosley, president of the Critical Path Institute in Tucson, Ariz., told the Associated Press on Tuesday.

The Critical Path Institute is a nonprofit partnership with the FDA that aims to speed the development of new drugs.

If the FDA considers the panel’s recommendations, this will likely cost the drug manufacturers a great deal of funding, but, on the other hand, it will help reduce the number of unforeseen health risks in the long-term.

There are nearly 24 million Americans having type 2 diabetes, a disease leading to kidney failure, blindness and heart disease.