Concerns Raised about Pradaxa Side Effects

Boston, MAAlthough concerns about Pradaxa side effects, including a risk of Pradaxa bleeding, are not new, some experts warn that the risks associated with Pradaxa are not fully appreciated. In fact, a letter written to the New England Journal of Medicine (3/1/12) by researchers in New Zealand, shows just how far concern about Pradaxa bleeding and Pradaxa heart attack have spread.

The letter notes that dabigatran (the generic name for Pradaxa) has been available in New Zealand since July 1, 2011, with no limits on its access. According to the letter's writers, within the first two months Pradaxa was available, around 7,000 patients started treatment. Because of concerns about bleeding events associated with the drug, a panel was convened to examine the risks and severity of bleeding events.

The letter notes that during a two-month period, 78 bleeding events were identified, including 12 events involving major bleeding. The causes of the bleeding included "prescriber error, impaired renal function, patient age and complications arising from the lack of a reversal agent." Seen as a major contributor to bleeding events was the use of Pradaxa in patients with severe renal impairment and the lack of a reversal agent.

"We are concerned that the potential risks of this medication are not generally appreciated," the researchers wrote. "The serious consequences of the lack of an effective reversal agent should not be underestimated. Prolonged bleeding increased morbidity and possibly contributed to the death of one patient." They noted that 22 of their patients experienced a bleeding episode even while using a reduced dose. The researchers conclude that in all patients, doctors must carefully evaluate the risks and benefits of using the drug.

Pradaxa is an anticoagulant used to prevent blood clots. It is designed to be used by patients with atrial fibrillation, who may have a higher risk of blood clots. In December 2011, the US Food and Drug Administration (FDA) announced it was investigating reports of serious bleeding events in patients who use Pradaxa to determine whether there were more bleeding events in patients who use the drug than would be expected. Pradaxa was approved in October 2011 to prevent stroke and blood clots in people who suffer from non-valvular atrial fibrillation.