Combining an Anticoagulant with NSAID or Aspirin Risky: Study
By Megan Brooks
NEW YORK - Patients with venous thromboembolism receiving anticoagulants have an increased risk of major bleeding when they add an NSAID or aspirin, a new study shows.
The message for clinicians is straightforward, said first author Dr. Bruce Davidson.
"If your patient is taking an old or new oral anticoagulant, tell him/her not to take an NSAID also (23% of them do, OTC, for headache, fever, sore back, etc)," he said in an email to Reuters Health.
"Taking an NSAID more than doubles their risk of a major bleed, and a quarter of those bleeds happened taking NSAIDs eight days or less. Same for aspirin, unless the patient needs to take aspirin for arterial disease. For other pain or fever, take generic Tylenol (less than 4 g/day. I use 1.5 extra strength generic Tylenol every 6 hours)," Dr. Davidson said.
He is a clinical professor of medicine in the division of pulmonary and critical care medicine at University of Washington School of Medicine in St. Louis.
Until now, the bleeding risks for anticoagulation combined with either aspirin or NSAID use have not been reported for patients on anticoagulant therapy for deep vein thrombosis or plumonary embolism, Dr. Davidson and colleagues pointed out in JAMA Internal Medicine online April 14.
They assessed the bleeding risk of combined therapy with an anticoagulant (rivaroxaban or enoxaparin-vitamin K antagonist) and an NSAID or aspirin in 8,246 patients with venous thromboembolism in the EINSTEIN DVT and PE study program; 4,130 patients received rivaroxaban and 4,116 patients received enoxaparin-VKA, of whom 1,884 (22.8%) and 1,202 (14.6%), respectively, received concomitant NSAID or aspirin therapy at any time during their study treatment. The EINSTEIN protocol "discouraged" NSAID use, the researchers note.
They say a first clinically relevant bleeding event occurred in 388 rivaroxaban-treated patients (9.4%) and 412 enoxaparin-VKA-treated patients (10.0%) and a first major bleeding event occurred in 40 (1.0%) and 72 (1.7%) patients, respectively.
During concomitant NSAID-anticoagulant use, the event rate (per 100 patient-years) for clinically relevant bleeding was 37.5 compared with 16.6 during anticoagulant use only. The hazard ratio with combined use was 1.77. The event rate for major bleeding during NSAID-anticoagulant use was 6.5 compared to 2.0 during anticoagulant use only (HR 2.37).
For aspirin-anticoagulant concomitant use, clinically relevant bleeding occurred with an event rate of 36.6 compared to 16.9 during aspirin nonuse (HR 1.70). Major bleeding in aspirin-anticoagulant-treated patients had an event rate of 4.8 compared to 2.2 during aspirin nonuse (HR 1.50).
Increases in risk for clinically relevant and major bleeding were similar for rivaroxaban and enoxaparin-VKA anticoagulation regimens.
"Physicians should inform patients about the potential for increased bleeding with these readily available commonly used drugs and advise patients to curtail their casual use," the authors conclude.
Should these findings change clinical practice? "They have changed my practice," Dr. Davidson told Reuters Health. "I previously didn't pay much attention to NSAID cautions in anticoagulated patients. Now I ask, 'You don't ever take Motrin or Advil or Aleve or aspirin or drugs like that, do you?'"
SOURCE: https://bit.ly/1ip22n0
JAMA Intern Med. 2014.
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