NOACs May Carry Lower Risk of Intraocular Hemorrhage Than Warfarin

Patients who are prescribed non-vitamin K antagonist oral anticoagulants (NOACs)—specifically dabigatran and rivaroxaban—are less likely than those given warfarin to develop intraocular hemorrhages over 1 year of follow-up, according to results of a retrospective analysis.

“Intraocular hemorrhages are a rare but potentially vision-threatening complication of systemic antithrombotic use,” write Katherine E. Uyhazi, MD, PhD (University of Pennsylvania Perelman School of Medicine, Philadelphia), and colleagues, noting that a few studies have suggested that the newer anticoagulants, and some antiplatelet agents, may increase the risk of experiencing these bleeds.

Yet use of NOACs is on the rise thanks to several factors; unlike warfarin, they don’t require routine monitoring and they offer “predictable pharmacokinetics, shorter half-life, reduced drug-drug interactions, and overall ease of use,” the researchers point out. They add: “Given the increasing number of patients using novel antithrombotics, the safety profile of these medications with regard to eye disease needs to be better understood.”

The study, published online recently ahead of print in JAMA Ophthalmology, examined 90-day and 1-year data from more than 200,000 patients in a large national insurance claims database. No significant difference in risk was observed at the earlier time point, but at 365 days, the risk of intraocular hemorrhage was lower with dabigatran (Pradaxa; Boehringer Ingelheim) or rivaroxaban (Xarelto; Janssen Pharmaceuticals) than with warfarin (HR 0.75; 95%CI 0.58-0.97).

Uyhazi and colleagues also compared a cohort of patients taking prasugrel (Effient; Eli Lilly) versus those taking clopidogrel. There were no differences in risk between the groups at either 90 days or 1 year.

“Our study suggests that there is not an increased risk of intraocular hemorrhage associated with the use of novel antiplatelet therapy, but novel anticoagulants may decrease the hazard of bleeding compared with warfarin,” the study authors write.

In an accompanying editorial, Daniel Caldeira, MD, PhD (University of Lisbon, Portugal), notes that the data “overlap with those from RCTs and support the safety of the novel drugs, particularly regarding intraocular bleeding.” However, the study did not include any patients taking ticagrelor (Brilinta; AstraZeneca), apixaban (Eliquis; Bristol-Myers Squibb), or edoxaban (Savaysa; Daiichi Sankyo), which are being increasingly used.

Caldeira also says safety data are needed to see if antidotes for the novel oral anticoagulants improve outcomes in patients developing intraocular bleeds.