A low-cost and widely available drug could reduce deaths in traumatic brain injury patients by up to 20%, new research suggests.

Depending on the severity of the injury, scientists say tranexamic acid (TXA) has the potential to save hundreds of thousands of lives.

It prevents bleeding into the brain by inhibiting blood clot breakdown.

Led by the London School of Hygiene & Tropical Medicine (LSHTM), the global randomised trial included 12,737 head injury patients who were given either intravenous tranexamic acid or a placebo.

The study, published in The Lancet, found that administration of TXA within three hours of injury reduced the number of deaths.

Scientists said the effect was greatest in patients with mild and moderate traumatic brain injury (TBI), with a 20% reduction in deaths.

However, there was no clear benefit in the most severely injured patients.

The trial found no evidence of adverse effects and there was no increase in disability in survivors when the drug was used.

Ian Roberts, professor of clinical trials at the London School of Hygiene & Tropical Medicine, who co-led the study, said: “We already know that rapid administration of tranexamic acid can save lives in patients with life-threatening bleeding in the chest or abdomen such as we often see in victims of traffic crashes, shootings or stabbings.

“This hugely exciting new result shows that early treatment with TXA also cuts deaths from head injury. It’s an important breakthrough and the first neuroprotective drug for patients with head injury.

“Traumatic brain injury can happen to anyone at any time, whether it’s through an incident like a car crash or simply falling down the stairs.

“We believe that, if our findings are widely implemented, they will boost the chances of people surviving head injuries in both high-income and low-income countries around the world.”

Patients were recruited from 175 hospitals across 29 countries.

A common complication of TBI is bleeding around the brain, which can lead to brain compression and death.

Patients with very severe head injuries are unlikely to benefit from tranexamic acid treatment because they often have extensive brain bleeding prior to hospital admission and treatment.

But the study found a substantial benefit in patients with less severe injuries who make up more than 90% of TBI cases.

Researchers say it is a leading cause of death and disability worldwide, with an estimated 69 million new cases each year.

The Clinical Randomisation of an Antifbrinolytic in Significant Head Injury (CRASH-3) trial is one of the largest clinical trials ever carried out into head injury.

Early treatment is critical because TXA prevents bleeds from getting worse, but cannot undo damage already done.

According to the study, there was a 10% reduction in treatment effectiveness for every 20-minute delay.

Antoni Belli, professor of trauma neurosurgery at the University of Birmingham and co-investigator for trial, said: “This is a landmark study.

“After decades of research and many unsuccessful attempts, this is the first ever clinical trial to show that a drug can reduce mortality after traumatic brain injury.

“Not only do we think this could save hundreds of thousands of lives worldwide, but it will no doubt renew the enthusiasm for drug discovery research for this devastating condition.”

Road accidents and falls are the most common causes of TBI worldwide.

In both cases, patients can experience permanent disability or death.

Representatives from UK charity Roadpeace were involved in the design of the trial.

Amy Aeron-Thomas, justice and advocacy manager from Roadpeace and co-author of the paper, said: “It’s always better to prevent road crashes in the first place, but these results show that if a crash can’t be prevented, death can still be avoided.

“Given the time to treatment implications, it’s more important than ever that the post-crash response is as efficient as possible.”

In the UK, 500mg of tranexamic acid costs roughly £1.55, so the total dose used in CRASH-3 would be about £6.20.

Patients were randomly allocated to receive a loading dose of 1g infused over 10 minutes, started immediately after randomisation, followed by an intravenous infusion of 1g over eight hours, or matching placebo.