Certain blood thinner drugs that reduce the process of blood clotting, used for treating irregular heart rate disorder may put patients with chronic kidney diseases (CKD) at a higher risk of bleeding, researchers have found.

The direct oral anticoagulants -- type of blood thinners -- are cleared by the kidneys to varying degrees, and their elimination is slower in individuals with CKD. This may predispose these patients to drug accumulation and a greater risk of bleeding events, the researchers said. "Despite sparse evidence in safety and effectiveness of direct oral anticoagulants in CKD, we saw that prescription of direct oral anticoagulants in the CKD population increased substantially over time," said Jung-Im Shin from Johns Hopkins University in Maryland, US.

"We also found that direct oral anticoagulant use was linked with a higher risk of bleeding compared to warfarin use in patients with CKD," Shin added. For the study, published in the Clinical Journal of the American Society of Nephrology, the team included 3,206 patients with atrial fibrillation who used direct oral anticoagulants and additional 3,206 patients with the disorder, who used the conventional anticoagulant warfarin.

The results showed that there were 1,181 bleeding events and 466 ischemic strokes over 7,391 person-years of follow-up -- number of years of follow-up multiplied by the number of people in the study. In patients without CKD, the risk of bleeding and benefits of preventing ischemic stroke between direct oral anticoagulant and warfarin use were similar.

On the other hand, patients with CKD who took direct oral anticoagulants had 23 per cent higher risk of bleeding compared with those on warfarin, but similar benefits from prevention of ischemic stroke. The findings suggests the need for caution while prescribing direct oral anticoagulants in patients with chronic kidney disease.