Apixaban added to anticoagulant arsenal

Anticoagulation therapies Anna D. Garrett, PharmD, BCPS

The FDA recently approved apixaban (Eliquis; Bristol-Myers Squibb) for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (AF).

Apixaban, a factor Xa inhibitor, is the third anticoagulant to receive FDA approval for this indication, adding to an ever-growing number of treatment options.

FDA based its approval on the positive results of the ARISTOTLE and AVERROES trials, after delaying approval in June of 2012 because of a request for further data. No new studies were required, but additional information on data management and verification was requested from the ARISTOTLE trial.

Apixaban will be dispensed with a patient Medication Guide that provides instructions on its use and drug safety information.

Source: FDA approves Eliquis. http://www.drugs.com/newdrugs/fda-approves-eliquis-reduce-risk-stroke-blood-clots-patients-non-valvular-atrial-fibrillation-3618.html. Accessed January 28, 2013.

Study addresses barriers to alteplase use

According to a recently published study, when barriers to use of the tissue plasminogen activator (tPA) alteplase (Activase; Genenetech) in acute ischemic stroke patients were identified and addressed, a modest increase in use followed. The study was conducted in nonspecialty acute-care community hospitals in Michigan.

These findings are important because many trials involve delivery of thrombolytic agents by stroke teams. This study shows that in the community setting, the safety, particularly with respect to symptomatic intracranial hemorrhage, matches historical numbers achieved by specialized stroke teams.

The researchers say they uncovered several key barriers to thrombolytic use in participating hospitals, including delay in patients’ presentation, communication with radiology departments, and poor availability of neurologists (many hospitals had only one or two neurologists, who typically worked in private, office-based community practices). Familiarity with treatment guidelines and physician motivation were also barriers. With the exception of presentation delay, all these barriers were addressed by one or more intervention elements.

The primary outcome of the INSTINCT trial was change in alteplase use in patients with stroke in emergency departments between the pre-intervention period (January 2005 to December 2006) and the post-intervention period (January 2008 to January 2010).

In intervention hospitals, the number treated increased from 89 (1.25%) of 7,119 patients in the pre-intervention period to 235 (2.79%) of 8,419 in the post-intervention period. In control hospitals, the number treated rose from 99 (1.25%) of 7,946 to 194 (2.10%) of 9,222.

In the target-population analysis, the increase in alteplase use in intervention hospitals was significantly greater than in control hospitals (1.00% to 2.62% vs 1.09% to 1.72%) but was still clinically modest (RR, 1.68; P=0.02).

The authors concluded that while use improved in the intervention hospitals, there is still a significant gap in the number of patients treated compared to the number of patients who are eligible to be treated. Only 2%-3% of stroke patients are being given tPA, but as many as 8%-11% may be eligible. Further study is needed to find more ways to improve usage.

Source: Scott PA, Meurer WJ, Fredericksen SM et al. A multilevel intervention to increase community hospital use of alteplase for acute stroke (INSTINCT): A cluster-randomized controlled trial. http://www.thelancet.com/journals/laneur/article/PIIS1474-4422%2812%2970311-3/fulltext. Accessed January 28, 2013.

FDA issues warning about novel anticoagulants and prosthetic heart valves

The FDA is following in the footsteps of the European Medicines Agency in warning that the anticoagulant dabigatran (Pradaxa; Boehringer Ingelheim) should not be used to prevent stroke or major thromboembolic events in patients with mechanical (also known as mechanical prosthetic) heart valves. A similar warning was issued for apixaban upon its recent approval.

The RE-ALIGN trial, which was studying this patient group, was recently stopped because dabigatran users were more likely to experience strokes, MI, and thromboses forming on the mechanical heart valves than were users of warfarin. There was also more postoperative bleeding after valve surgery in the dabigatran users than in the warfarin users.

FDA says healthcare professionals should promptly transition any patient with a mechanical heart valve who is taking dabigatran to another medication. It also notes that the use of dabigatran in patients with bioprosthetic valves “has not been evaluated and cannot be recommended.”

Warfarin is the only oral anticoagulant indicated for thrombosis prevention in patients with mechanical prosthetic or bioprosthetic heart valves.

Source: http://staging.theheart.org/article/1487131.do. Accessed January 28, 2013.

Anna D. Garrett is a clinical pharmacist and president of Dr. Anna Garrett, a health and wellness coaching company in Asheville, N.C.