January 19,2011

A drug used to stem bleeding for heavy menstrual periods may do the same for hemorrhaging patients after a traumatic injury, according to a new study. Tranexamic acid, which works by keeping blood clots intact, could prevent countless deaths in situations where extensive blood loss occurs, according to the study.

“There is now very clear evidence that this drug saves lives in bleeding trauma patients,” said Ian Roberts, lead study author and professor of public health at the London School of Hygiene and Tropical Medicine. “Patients in car crashes, patients who are shot or stabbed. Or it could be a soldier in places like Afghanistan and Iraq.”

Using tranexamic acid to treat patients in the wake of traumatic injury causing massive bleeding could save about 2,000 lives each year in the United States alone, said Roberts – even more worldwide. The problem, he says, is that few doctors are aware of evidence suggesting the treatment works.

“This treatment could save between seventy and one hundred thousand lives a year if doctors knew about it,” said Roberts. “A lot of people will find it a really strange idea that a treatment shown to be effective is not being used.”

Tranexamic acid belongs to a group of drugs called antifibrinolytics, drugs that inhibit blood clots from dissolving. When a patient is bleeding profusely, there are two processes in the body occurring simultaneously, said Roberts – clot formation and clot breakdown. While the body struggles to form clots, and thereby stanch bleeding, there are competing enzymes produced in the body that break down clots.

“We don’t want [to break down clots] when we’re bleeding to death,” said Roberts. “We want all the clotting we can get.”

This most recent study about tranexamic acid, published by the Cochrane Library, is based primarily on data from a 2010 study called CRASH-2. The study involved 20,211 trauma patients in several countries who had, for example, been shot, stabbed or involved in a car crash – or who were at  some other risk for significant bleeding. Patients who received tranexamic acid were 15% less likely to bleed to death – and less likely to die, period – than those who received placebo.

Roberts was the chief investigator for the CRASH-2 trial which was funded, in part, by one of the makers of tranexamic acid, Pfizer.

In prescribing information by Pfizer for Cyklokapron, a brand of tranexamic acid used to prevent bleeding in hemophiliacs following tooth extraction, risks in animals (given much higher doses of tranexamic acid than humans typically receive) include retinal abnormalities.

“No retinal changes have been reported or noted in eye examinations in patients treated with tranexamic acid for weeks to months in clinical trials,” according to prescribing information issued by Pfizer. “However, visual abnormalities, often poorly characterized, represent the most frequently reported postmarketing adverse reaction in Sweden.”

And prescribing information for Lysteda, the drug used to treat heavy menstrual bleeding, describes reports of deep vein thrombosis and visual disturbances.

“We found no evidence of adverse effects” during the CRASH-2 trial, said Roberts.

Researchers plan to test tranexamic acid as a possible treatment for excessive bleeding after childbirth and to quell bleeding after traumatic brain injury.

Another good article on the subject is from MedicalNewToday.