Date of Graduation

8-14-2010

Degree Type

Capstone Project

Degree Name

Master of Science in Physician Assistant Studies

First Advisor

James Ferguson PA-C, MPH

Second Advisor

Annjanette Sommers MS, PAC

Third Advisor

Rob Rosenow PharmD, OD

Abstract

Background: Thromboembolic events are a substantial healthcare concern, both in hospital and community settings. The current standards of anticoagulation, heparin and warfarin, have well-demonstrated efficacy, but come with sizeable drawbacks. Heparin requires parenteral administration, and carries the risk of osteoporosis and severe thrombocyotopenia. Warfarin, the only oral anticoagulant available, gives inconsistent results, and thus requires frequent laboratory monitoring and adjustment. A fixed-dose oral anticoagulant would ease the burden of anticoagulation both for patients and prescribers, and would likely increase adherence to prophylactic guidelines. Dabigatran etexilate, an oral direct thrombin inhibitor, is poised to offer this advantage, and has been appraised in several diverse settings of thromboembolic risk. While authorized for use in Europe, it awaits FDA approval in the United States.

Methods: An exhaustive search of available medical literature was performed on five databases: MEDLINE, CINAHL, ISI World of Science, the National Clinical Trials Registry and the Boehringer Ingelheim Clinical Trials database, looking for studies comparing this new drug to conventional anticoagulation therapy. Using the keywords dabigatran, warfarin, heparin, enoxaparin, BIBR 1048 and Pradaxa resulted in 327 entries. Included for review were original, randomized controlled trials, comparing dabigatran to warfarin or heparin therapy. Exclusion criteria were: animal studies, non-English language publications, and studies without an active control.

Results: Of the studies reviewed, seven showed dabigatran to have equal or superior efficacy to various heparin and warfarin protocols. One study showed dabigatran have inferior efficacy, when compared to enoxaparin for perioperative anticoagulation. Bleeding rates varied between the trials, but were generally comparable to control therapy. Among all the trials, two issues arose concerning safety and tolerability; patients taking dabigatran had a higher rate of dyspepsia in several trials, and one trial demonstrated an increased rate of myocardial infarction.

Conclusion: Dabigatran stands to offer crucial improvements in anticoagulation therapy. Current studies show promise, but firm conclusions are limited by several factors in trial design, including variations in control therapy, minimal long-term studies and a lack of independent investigation. For dabigatran to be established as an alternative short-term therapy in hospitalized patients, further data is needed comparing it to varying intensities of parenteral anticoagulation. In regards to its outpatient indications, the ongoing studies of long-term dabigatran therapy will help to define its safety profile and fortify the efficacy picture demonstrated thus far.

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