A large-scale comparison of blood thinners by researchers from University College London has identified the drugs with the lowest risk of gastrointestinal bleeding.
The researchers found that the anticoagulant drug, apixaban, one of the two most common blood thinners, had the lowest risk of gastrointestinal bleeding.
The full findings of the research have been published in the journal Annals of Internal Medicine.
Why do people use blood thinners?
Blood thinners are used to prevent strokes in people with atrial fibrillation, a condition that slows or disrupts the heartbeat, affecting 33 million people across the world. They are also used to prevent blood clots and reduce the risk of cardiac arrest.
Blood thinners are useful in stopping bleeding; however, they can block blood vessels and prevent blood flow to vital organs such as the brain, heart and lungs if they form in the wrong place. The drugs work by interrupting the process involved in the formation of blood clots. Although they are known as blood thinners, they do not actually thin the blood.
Blood thinning medicine has recently become more common with warfarin, a common oral anticoagulant, which requires low levels of follow-up monitoring and has a low risk of side effects.
Comparing the most common options
The researchers compared the efficacy and risk of side effects in the four most common blood thinners. Data from over 500,000 blood thinner users in the UK, France, Germany and the US were reviewed. The drugs in question were apixaban, dabigatran, and rivaroxaban.
Data showed that all four drugs had comparable outcomes for ischemic stroke, brain bleeds and all-cause mortality. However, a difference in the risk of gastrointestinal bleeding was identified by the researchers, which is a common serious side effect of many anticoagulants.
The study revealed that apixaban had the lowest risk of gastrointestinal bleeding, with a 19-28% lower risk when compared to each of the other three blood thinners. The researchers were pleased that their findings were relevant to people over the age of 80 and people with chronic kidney disease, as these two groups are often underrepresented in clinical trials.
“Direct oral anticoagulants have been prescribed with increasing frequency worldwide in recent years, but evidence comparing them directly has been limited. Our results indicate that apixaban may be preferable to other blood thinners because of the lower rate of gastrointestinal bleeding and similar rates of stroke, a finding that we hope will be supported by randomised controlled trials,” said co-lead author Dr Wallis Lau of the UCL School of Pharmacy.
“As with all medications, potential risks and benefits can differ between people, so considering the full spectrum of outcomes and side effects will still be necessary for each individual patient,” he added.