Atrial Fibrillation and Heart Disease
How Are Medications Used to Treat Atrial Fibrillation? continued...
Anticoagulant drugs are better than antiplatelets at preventing strokes in people with AF. But until recently, the only anticoagulant approved by the FDA for AF was warfarin. While warfarin is highly effective and relatively inexpensive, there are problems associated with its use. For instance:
- Someone taking warfarin needs regular blood tests to adjust the dosage based on the way the blood clots.
- Proper dosage depends on a number of factors such as body size and age.
- Warfarin interacts with a wide range of foods as well as other drugs. So people taking warfarin need to make adjustments in their diet and have to be careful about what other medications they take.
Pradaxa was approved by the FDA in 2010 for treating AF. Studies show it's at least as effective as warfarin at preventing strokes and perhaps even more effective at higher dosages.
The main advantage of Pradaxa is that it works in a different way than warfarin does. As a result, it does not have the same kind of problems that are associated with warfarin. For example:
- People do not need to have regular blood tests to determine whether the dosage needs adjustment.
- There are no dietary changes required.
- Pradaxa does not interact with a large number of drugs the way warfarin does.
The differences between the two drugs may make Pradaxa an attractive alternative for people who have difficulty taking warfarin. But there are also issues associated with the use of Pradaxa that need to be considered. For example:
- Cost may be the biggest issue. Because it is only available as a brand-name drug, Pradaxa is significantly more expensive than warfarin, which can be bought as a generic.
- In some studies, the higher dosage that produced greater protection against stroke also increased the risk of heart attack.
- The drug may not be appropriate for someone with kidney problems without regularly monitoring its effect on kidney function.
- Pradaxa produces more stomach pain and upset than warfarin.
Both Pradaxa and warfarin carry a risk of serious bleeding. So if you take either medication, be sure to discuss the risks with your doctor and to follow the doctor's instructions for taking it.
Xarelto is also approved to prevent stroke in patients with AF not caused by a heart valve problem. It also increases the risk for bleeding. But Xarelto can also increase the risk of stroke if people stop taking it without medical supervision. That's the main warning in the "black box" on the Xarelto label. A black box warning is the FDA's strongest warning. Xarelto had previously been approved to prevent blood clots in patients receiving hip and knee replacements and in those with deep vein thrombosis.
The usual dose of Eliquis is 5 milligrams, taken twice a day with or without food. In a study of more than 18,000 patients comparing Eliquis with warfarin, those on Eliquis were less likely to have a stroke. In another study of people with atrial fibrillation who could not or chose not to take warfarin, Eliquis was more effective than aspirin at preventing stroke.