Sunday 22 July 2018

New blood-thinner drugs a safer way to cut stroke risks

3D rendered illustration of many blood cells
3D rendered illustration of many blood cells
Eilish O'Regan

Eilish O'Regan

Thousands of Irish patients who take blood-thinning drugs to reduce their risk of stroke have been reassured by a new study showing the more modern therapies are a safe alternative to the older medicine warfarin.

The newer drugs known as direct oral anticoagulants (DOACs), used to treat serious blood clots, are associated with reduced risks of major bleeding compared with the older anti-clotting agent, the study in the 'British Medical Journal' said.

The drugs work by making the blood less likely to clot.

For many years, warfarin has been the main treatment for potentially fatal blood clots, known as venous thromboembolism (VTE).

Over 50,000 people are believed to still be on warfarin in Ireland and in many cases it remains first choice for those who are used to taking it.

But DOACs are increasingly being used as an alternative to warfarin because patients don't need regular tests to check if they have the right amount of drug in their bloodstream. Clinical trials have shown a reduced or similar risk of major bleeding for DOACs compared with warfarin.

But such trials involve only carefully selected patients, so bleeding rates often do not reflect those seen in everyday ("real world") clinical practice.

Furthermore, most observational studies have included only patients with irregular heartbeat (atrial fibrillation or AF), creating an information gap for patients without these conditions.

Researchers at the University of Nottingham supported by National Institute of Health Research set out to investigate the risks and benefits associated with the three commonest types of DOACs (dabigatran, rivaroxaban, and apixaban) compared with warfarin in patients with and without AF.

Using data from two large UK primary care databases, they identified 196,061 patients who started or restarted anticoagulants (after more than a 12-month gap) between 2011 and 2016.

A total of 132,231 patients were taking warfarin, 7,744 dabigatran, 37,863 rivaroxaban, and 18,223 apixaban. Overall 53pc (103,270) were diagnosed with AF and 47pc (92,791) were prescribed anticoagulants for other conditions.

Patients were monitored for major bleeds leading to hospital admission or death, ischaemic stroke, VTE, and death from any cause ("all cause mortality").

After taking account of several known risk factors, the researchers found that apixaban was associated with a lower risk of major bleeding, particularly brain and gastric bleeds, in patients with and without AF, compared with warfarin.

Irish Independent

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