Wednesday, June 16, 2010

New use for old drug could save thousands of lives

A cheap, common drug used to help women with heavy periods could save thousands of lives worldwide, by helping to prevent heavy bleeding after injuries caused in car crashes, shootings, or stabbings.

What do we know already?

Despite advances in surgery and medicine, millions of people die worldwide as a result of injuries caused by accidents and deliberate violence. These types of injuries are usually called 'trauma' by doctors. One of the main causes of death is heavy bleeding.
Heavy bleeding means there's not enough blood carrying oxygen around the body. Organs like the brain and heart stop working without a constant supply of oxygen.
The body's response to trauma injuries is to attempt to keep the blood vessels open, by breaking down blood clots in a process called fibrinolysis. Unfortunately, this can make it hard to stop the bleeding. The same thing happens after surgery, because the body reacts in the same way.
Doctors have used anti-fibrinolytic drugs after surgery for many years, to reduce blood loss. One anti-fibrinolytic drug, tranexamic acid, is cheap and known to be safe. It's also used to help reduce bleeding for women who have heavy periods.
Now researchers have tried using injections of tranexamic acid for people who have serious bleeding from trauma injuries. They carried out a very big study, in 40 countries worldwide, to see whether it would help to prevent deaths from bleeding. Half the people in the study were injected with the drug, and half with saline solution as a placebo.

What does the new study say?

People were less likely to die if they'd had tranexamic acid. In total, 16 percent of people died who'd had the placebo injection, compared with 14.5 percent of people who'd had tranexamic acid. The researchers calculated this could save 100,000 deaths each year worldwide. In the UK, about 1,800 people die each year from bleeding after injury, and the researchers calculate that routine use of tranexamic acid could save the lives of about 280 of these people.
The drug made no difference to the risk of either getting or dying from a complication such as a heart attack, stroke, or blood clot in the lung. That's important, because a drug that works to prevent bleeding might have increased the chances of getting a blood clot that caused this type of problem.
Interestingly, there was little difference in the numbers of patients who needed blood transfusions. About half of people had transfusions, whether or not they'd had tranexamic acid. This might suggest that the benefit of tranexamic acid wasn't purely down to a decrease in bleeding. However, it could also be because more people treated with tranexamic acid lived long enough to receive a transfusion, or simply that it can be hard to tell whether someone needs a transfusion or not.

How reliable are the findings?

The study was a randomised controlled trial, which is the best sort of study for finding out whether a treatment is helpful. The study looked at more than 20,000 patients, and found a clear result that those treated with tranexamic acid were more likely to survive. The results should be very reliable.

Where does the study come from?

The study was carried out by researchers from 40 countries around the world, including countries from Europe, South America, Asia, and Africa. It was published in The Lancet medical journal, owned by the publishing company Elsevier. It was paid for by the UK's Health Technology Assessment programme.

What does this mean for me?

The authors of the study recommend that doctors treating trauma patients should consider using tranexamic acid in cases of heavy bleeding, or where the patient is at risk of heavy bleeding. But writing in a separate article in the same journal, another doctor warns that very high doses of tranexamic acid have been linked to seizures after heart surgery. He says doctors should be cautious, especially if using other types of anti-fibrinolytic drugs.
The proportion of people in the study who died of their injuries may seem high. But that's because many of the injuries happened in parts of the world like rural Africa or India, where it may take longer for accident victims to get good-quality medical care. In a country like the UK, the death rate from injuries is likely to be much lower.

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