LONDON — A cheap drug that can stop bleeding in recently injured accident patients could potentially save the lives of tens of thousands worldwide, a new study says.

Researchers studied the effects of tranexamic acid, or TXA, in more than 10,000 adult trauma patients in 40 countries who received the drug within 8 hours of being injured. They compared those patients' outcomes to more than 10,000 accident victims who got a placebo treatment. The study was published online Tuesday in the medical journal Lancet.

Doctors found that patients who got TXA had a 15 percent lower chance of dying from a hemorrhage than those who didn't get it. They also had a 10 percent lower chance of dying from any other cause, including organ failure and a head injury, versus patients who didn't receive TXA. The study was paid for by the British government.

The drug is commonly used in wealthy countries during elective surgeries to stop bleeding, but isn't prescribed for accident victims.

TXA is off-patent and manufactured generically by many companies. It costs about 3 pounds ($4.50) per gram, and a typical dose is two grams. It is usually given via an injection and would be relatively easy to introduce, even in poor countries, experts said.

"This is one of the cheapest ways ever to save a life," said Ian Roberts, a professor of epidemiology at the London School of Hygiene and Tropical Medicine and one of the study's main investigators.

Previous tests of the drug regarded its use in elective surgeries, such as heart operations, but this was the first study to test the drug on accident victims.

Doctors were worried it might increase side effects such as blood clots in the heart and lungs, strokes or heart attacks. There was no evidence of that in the Lancet study, though the authors said they might have missed some of these incidents.

For people between 5 and 45, accidents are the second leading cause of death worldwide after AIDS, and about 600,000 injured patients bleed to death every year. Nearly 6 million people die of injuries every year, more than AIDS, malaria and tuberculosis combined.

Roberts and colleagues estimated that if TXA were readily available, between 70,000 and 100,000 lives a year could be saved. Though the drug wasn't tested in children, he said it would almost certainly work in them as well.

Etienne Krug, director of violence and injury prevention and disability at the World Health Organization, said the drug would likely have the biggest impact in developing countries such as China and India, where 90 percent of injury-related deaths occur.

"People often have a fatalistic attitude about accidents and think nothing can be done to save people," he said. "But this study shows that isn't true."

Experts said rolling out TXA could save as many lives as other measures such as making seatbelts compulsory or strengthening drunk-driving laws.