Adverse events in patients initiated on dabigatran etexilate therapy in a pharmacist-managed anticoagulation clinic

Purpose: Warfarin has been the treatment of choice in preventing thromboembolic events, but problems such as the need for frequent dose adjustment and monitoring of coagulation status, including multiple drug and food interactions, make its use challenging. Dabigatran etexilate is a new oral direct thrombin inhibitor, given in fixed doses not requiring routine coagulation monitoring. This study documented adverse drug events (ADEs) recorded in patients started on dabigatran etexilate therapy, including those who were previously controlled on warfarin and those who were anticoagulant naïve.

Methods: A total of 222 patients were initiated on dabigatran etexilate therapy between October 15, 2010 and April 1, 2012. Forty-three percent of these patients were previously stable on warfarin therapy while fifty-seven percent of these patients were anticoagulant naïve.

Results: Fifty-four of these 222 patients (24.3%) developed an ADE while on dabigatran etexilate. The average time to event after the start of dabigatran treatment was 48.4 days (range 1-344). Twenty-four out of the 54 patients (44.4%) experienced a major ADE requiring a hospital visit and four of these patients died; one death was directly related to dabigatran etexilate therapy. The remaining thirty patients (55.6%) experienced a clinically relevant non-major ADE. Of the fifty-four patients, thirty-one were male. The average age of the patients was 73.7 years (range 54-89) and the average patient weight was 93.2kg (range 46.8-159.1kg). Fifty-seven percent of those who experienced an ADE were previously controlled on warfarin therapy.

Conclusions: While many clinicians have been interested in utilizing the new direct thrombin inhibitor dabigatran etexilate, this new therapy is not without risks. This study documented adverse events (ADEs) recorded in fifty-four patients out of a total of 222 patients (24.3%) who were initiated on dabigatran etexilate therapy over an eighteen month period. ADEs were most common in patients who were previously controlled on warfarin therapy.