December 04, 2015
Which statin is most likely to not increase bleeding risk in atrial fibrillation patients on the anticoagulant dabigatran?
d. none of the above
A recent study involving nearly 46,000 older atrial fibrillation (AF) patients who took dabigatran showed concomitant use of the statins lovastatin or simvastatin increased risk of bleeding that required hospitalization or emergency room visits by 40%. There was no difference in the risk of stroke in patients who were prescribed other statins. The researchers focused on simvastatin and lovastatin because previous studies suggested the two statins could affect the disposition of dabigatran either through inhibition of P-glycoprotein at the site of absorption or carboxylesterases, according to study lead author Dr. Tony Antoniou, a pharmacist at St. Michael’s Hospital in Toronto. He said patients on dabigatran who require statin therapy should be given rosuvastatin, atorvastatin, fluvastatin, or pravastatin — cholesterol-lowering drugs that aren’t expected to heighten the risk of bleeding by increasing the amount of dabigatran absorbed by the body.
The study’s findings aren’t without a bit of controversy. Dr. Paul Thompson, chief of cardiology at Hartford Hospital, said the study is provocative, but flawed, because the researchers did not measure and compare dabigatran levels in patients on different statins. He also pointed out that lovastatin and simvastatin are older statins and patients on the drugs could have been on the therapies for an extended time because they were sicker and had higher lipid levels. Dr. Thompson emphasized that statins and anticoagulants are life-saving therapies that should not be stopped based on the conclusions of a single study.