Aspirin May Equal Pricier Drug for Preventing Clots
After hip replacement, no disadvantage found for the low-cost treatment
Five people on dalteparin and one on aspirin developed a blood clot. The absolute difference between the two therapies was 1 percent. Bleeding events serious enough to require treatment occurred in five people on dalteparin, and two on aspirin.
Anderson said the difference in bleeding events wasn't statistically significant, but there was a trend toward aspirin being the safer alternative. However, it's too soon to tell definitively whether aspirin might cause less bleeding, he said.
Anderson said the researchers had to stop the study early because they weren't able to recruit the desired number of patients. While the study was under way, Xarelto was approved, and because it's a pill instead of an injectable like dalteparin (brand name Fragmin), it became difficult to find volunteers for the multiple injection part of the trial.
The researchers are now duplicating the study, but comparing Xarelto to aspirin this time. They're also including people having knee replacement surgery, and they're only using five days of initial treatment with the more powerful blood-thinner.
"If aspirin turns out to be as good as Xarelto, given the number of joint [replacement] surgeries done in North America, it could save the health care system millions if it's proven to be at least as effective," said Anderson.
Fareed said he would not use aspirin immediately after the surgery. "But once that initial phase settles down, I think aspirin is a good option. And, I'm confident that the bleeding will be less with aspirin," said Fareed.
He said doctors may not turn to aspirin right away, and would probably wait until medical groups write new guidelines suggesting aspirin as the standard of care. But it's certainly a topic that patients could bring up with their doctor before surgery, he suggested.
"I think we have demonstrated that a very simple, inexpensive oral therapy appears to be as good as a more expensive, more potent, less convenient anticoagulant agent for the prevention of blood clots following total hip replacement," concluded Anderson.