Are storm clouds already gathering over Pradaxa?Critics of blood-thinner drug troubled by events in New Zealand
(Oct. 18, 2011) If some safety advocates are correct, a drug worth keeping a skeptical eye on is the blood thinner Pradaxa because of its propensity to increase the risk of bleeding – perhaps fatally so, according to the manufacturer’s own label warning.
Already, in New Zealand, Pradaxa is tied to at least two deaths amid reports that scores of elderly users there experienced bleeding ranging from mild to severe.
Pradaxa – manufactured by Boehringer Ingelheim Pharma – is indicated to reduce the risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation. Market observers believe Pradaxa could eventually overtake Coumadin (warfarin) as the therapy of choice among physicians.
The problems in New Zealand resulted when patients at elevated risk for internal bleeding were given Pradaxa.
As of last month, New Zealand’s Centre for Adverse Reactions Monitoring reported 50 incidents involving Pradaxa and internal bleeding. Discontinuing Pradaxa intake ended the bleeding for many of the affected patients, although some nonetheless required medical intervention, including transfusions.
Critics allude that Pradaxa has not been adequately studied. They contend the gap in knowledge about its full effects is the result of efforts to hurry the drug to market ahead of at least two others – one of which is said to have the potential to dominate the arena. These observers theorize that the manufacturer hoped to quickly convince as many physicians as possible to develop a prescription-writing preference for Praxada before Eliquis from Pfizer and Bristol-Myers Squibb and Xarelto from Bayer and Johnson & Johnson could enter the competition for market share.
(Of the two, Eliquis is thought likely to be the stronger market performer, if clinical trial results and the investment community’s favorable reaction to that study are any indicator.)
Pradaxa, however, does have its defenders. In their view, Pradaxa owns a better safety profile than Coumadin. For example, a 2009 New England Journal of Medicine study found that a 150-mg dose of Praxada was associated with lower rates of stroke and systemic embolism than warfarin – although both products at that dose had similar rates of major hemorrhage. Further, the journal reported that the two at lower doses were similar with regard to stroke and systemic embolism risks, but observed that Praxada in reduced strength had lower rates of major hemorrhage.