NSAIDs increase bleeding risk in patients taking anticoagulants

January 10, 2015

A Danish study of 150,900 patients found that the risk of serious bleeding doubled when patients were treated with NSAIDs.

Patients with atrial fibrillation (AF) receiving antithrombotic treatment are at increased risk for bleeding if they also take a nonsteroidal anti-inflammatory drug (NSAID), even for a short period, a new nationwide Danish study has found.

The data suggest that a serious bleeding event occurs in up to one in 400 to 500 patients with AF exposed to an NSAID for two weeks, and that the risk is elevated for patients taking selective cyclooxygenase (COX)-2 inhibitors or nonselective NSAIDs.

The analysis included 150,900 patients, median age 75 years, who were hospitalized with a first-time diagnosis of AF between 1997 and 2011. During a median follow-up of 6.2 years, 35.6% of patients were prescribed an NSAID.

Study participants had a mean HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) score of 1.5 and mean CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke, vascular disease, sex) score of 2.8. Approximately 70% were being treated with an antiplatelet or oral anticoagulant.

The study showed that serious bleeding events, including intracranial and gastrointestinal bleeding, occurred in 11.4% of the patients; thromboembolic events occurred in 13.0%. The absolute risk for serious bleeding with 14 days of continuous NSAID exposure was 3.5 events per 1,000 patients vs. 1.5 events per 1,000 patients without NSAID exposure for an absolute risk difference of 1.9 events per 1,000 patients. In patients treated with oral anticoagulant therapy, the absolute risk difference was 2.5 events per 1,000 patients.

The study showed that the risk for serious bleeding with NSAID treatment was doubled compared with no NSAID treatment. The risk for thromboembolism was also increased.

Source: Lamberts M, Lip GYH, Hansen ML, et al. Relation of nonsteroidal anti-inflammatory drugs to serious bleeding and thromboembolism risk in patients with atrial fibrillation receiving antithrombotic therapy: A nationwide cohort study. Ann Intern Med. 2014;161:690–698.

Reversal agent for apixaban shows promise

Results from the Phase 3 ANNEXA-A (Andexanet Alfa a Novel Antidote to the Anticoagulant Effects of fXA Inhibitors – Apixaban) studies showed that the drug produced rapid and nearly complete reversal (approximately 94%) of the anticoagulant effect of Eliquis (apixaban) in healthy volunteers ages 50–75.

The trial included 33 subjects, with 24 randomized to andexanet alfa and nine to placebo. In the study, reversal was achieved two to five minutes after completion of a bolus dose of andexanet alfa. The reversal of anti-Factor Xa activity correlated with a significant reduction in the level of free, unbound Eliquis in the plasma, consistent with the mechanism of action of andexanet alfa. Additionally, andexanet alfa restored thrombin generation to what were baseline normal levels before initiation of Eliquis therapy.

The drug is an FDA-designated breakthrough therapy because there is currently no approved reversal agent for target-specific anticoagulants.

Source: Positive results for factor Xa inhibitor antidote: ANNEXA-A. http://www.medscape.com/viewarticle/832648. Accessed November 26, 2014.

 

Dementia risk increases with dual anti-stroke therapy in atrial fibrillation

A new study investigating the long-term use of warfarin in conjunction with antiplatelet therapy using aspirin or clopidogrel may result in an increased risk of dementia in patients with atrial fibrillation.

The study, presented at the American Heart Association's (AHA) Scientific Sessions 2014, followed 1,031 AF patients for up to 10 years. None of the participants had a previous history of stroke or dementia.

The researchers found that patients with an INR>3.0 on at least 25% of their monitoring tests were more than twice as likely to be diagnosed with dementia than patients who had an elevated INR less than 10% of the time.

The increase in dementia risk was higher than that observed in a previous study examining warfarin use only. These previous findings led to the conclusion that brain injury caused by both micro bleeds and clots plays a key role in the development of dementia among AF patients. The results of this study appear to support this theory as well.

Medical News Today. Dementia risks rise with overuse of anti-stroke dual-drug combo. http://www.medicalnewstoday.com/articles/285471.php. Accessed November 26, 2014.