Chicago ? A drug widely used to prevent excessive bleeding during heart surgery appears to raise the risk of dying in the five years afterward by nearly 50 percent, an international study found.

The researchers said replacing the drug – aprotinin, sold by Bayer AG under the brand name Trasylol – with other, cheaper medications for a year would prevent 10,000 deaths worldwide over the next five years.

The findings were more bad news for Trasylol: The same scientists found the drug raised the risk of kidney failure, heart attacks and strokes in a study published last year. Most of the deaths in the new study were related to those problems.

Bayer said in a statement that the findings were unreliable because Trasylol tends to be used in more complex operations and the researchers’ statistical analysis did not fully account for the complexity of the surgery cases.

Nevertheless, the drug company said it will “work with regulatory agencies and external experts in the field to further evaluate the findings.”

The study, published in today’s Journal of the American Medical Association, intensifies questions about how best to track the safety of drugs after they have gone on the market. The Food and Drug Administration approved aprotinin in 1993.

Birth control pills

Meanwhile, a consumer group is calling for a certain low-dose birth control pill to be removed from the market, saying the pill increases a woman’s risk of a potentially deadly blood clot more than others.

All contraceptive pills carry a very low risk of blood clots that, even more rarely, can travel to the lungs and kill. It is a side effect of the pills’ hormones, estrogen and progestin.

But “third-generation” oral contraceptives that contain a type of progestin called desogestrel can double that risk, the advocacy group Public Citizen said in a petition filed with the FDA.

That means about 30 blood clots per 100,000 users, compared with 15 blood clots per 100,000 users of older “second-generation” birth control pills that are just as effective, Public Citizen said.

Public Citizen contended that after years of research showing no extra benefit for desogestrel-containing contraceptives, it was time for users to switch to older, safer birth control pills. It was posting a video explaining the petition on YouTube to get that message to younger pill users.