Journal Of The American Medical Association Publishes Findings

A new study published in the Journal of the American Medical Association has identified a higher than expected rate of serious bleeds associated with use of the oral anti-coagulant Pradaxa.

Researchers at the University of Pittsburgh analysed the frequency of major bleeds using a random sample of five per cent of atrial fibrillation - or irregular heartbeat – patients within the US Medicare database treated with Warfarin or Pradaxa between October 1st 2010 and October 31st 2011.

Analysis of the outcomes for a total of 1,302 Pradaxa patients and 8,102 Warfarin patients identified an elevated risk of major bleeds for patients taking Pradaxa compared to Warfarin of just over 50 per cent.

The results contrast starkly with initial analyses submitted to the regulators by the manufacturer of Pradaxa, Boehringer Ingelheim, which reported a statistically significant reduction in major bleeds in Pradaxa patients compared to Warfarin.

Irwin Mitchell's Matthew Newbould, a specialist solicitor in medical device and pharmaceutical litigation, commented: “Pradaxa has been the subject of a great deal of controversy since its approval for use in atrial fibrillation in 2011.

“At the very outset the American Food and Drugs Administration identified discrepancies in the data collection and the design of the manufacturer’s trial. Some commentators also referred to the relative youth of the trial group, and the relatively poor treatment compliance within the Warfarin comparison group, all of which would tend to skew the results in favour of Pradaxa.

“This study appears to identify a discrepancy between real life bleeding rates and those in manufacturer’s trials, although it must be said that this is only one amongst a long line of similar studies, some of which  favour Warfarin and some of which favour Pradaxa in terms of bleeding risk.

“Of more concern are the facts that particular sub-groups of patients, including those over 75 years of age, with impaired kidney function or low body weight stand a significantly greater risk of bleeding, and that there is no known reversal agent for Pradaxa in the event of a major bleed requiring intervention. The manufacturer has already settled large scale litigation in the US arising from these issues.

“The authors of this study advise prescribers to exercise caution in the use of Pradaxa. Patients with Atrial Fibrillation or DVT considering the use of this drug are well advised to do the same, and discuss in detail the relative risks of the drug compared to Warfarin with their physician before proceeding.”