Up until recently, when physicians treated patients for thromboembolism (blood clots) or patients who might be at risk for the development of a blood clot, the only oral drug available was warfarin. Warfarin (brand names Coumadin or Jantoven) has been around for years, and when used appropriately is a safe treatment plan for reducing the risk of stroke and blood clots. Like any medication, there are always potential side effects or risks. Also, like any medication, those risks are weighed against its potential benefits, thereby allowing a treating physician to make the most appropriate treatment plan for an individual patient.
There are four main drawbacks to taking Coumadin or Jantoven:
- Regular blood draws are required to be sure the right dose is being administered (every patient’s dose is specific to their body’s response to the drug).
- There are many potential drug interactions with warfarin that may lead to either an increase or decrease in its blood levels.
- All the cruciferous vegetables (those foods high in Vitamin K, such as cauliflower, cabbage and broccoli) counteract warfarin, making dietary guidelines for anticoagulants very important.
- There is a narrow therapeutic index for warfarin, which, in some patients, may lead to very difficult warfarin dosing. If the blood level is too low it will not be effective and if it is too high, there is an increased chance of bleeding.
Three new warfarin and Coumadin alternatives
Recently, three drugs were approved for use in the U.S. that are considered alternatives to warfarin:
- Dabigatran (Pradaxa)
- Rivaroxaban (Xarelto)
- Apixiban (Eliquis)
There are some basic differences in the specific mechanism of action of these three drugs, but, more important, there are several advantages to them over warfarin.
- They allow standard doses that may change based on an individuals baseline kidney function or age.
- Most important from a patient’s perspective, these medications do not require any blood monitoring.
- There are no concerning food interactions with these new agents, and only very limited prescription drug interactions that have been identified.
- Several scientific studies conclusively showed that these medications have a lower risk of spontaneous bleeding when compared to warfarin, making them potentially safer from that perspective.
Weighing the choices
As with all treatment options in medicine, there are always advantages and disadvantages. The biggest disadvantage to these new agents is their cost. Since they are not generic, they are more expensive than Coumadin or Jantoven and often not completely covered by insurance plans. That issue, however, should be weighed against the convenience of no weekly or bi-monthly blood draws, concerns for multiple drug interactions, etc.
The other disadvantage of these agents is more of a theoretical one. Warfarin can be easily reversed with either certain blood product infusions or with the administration of Vitamin K. To date, there are no reversal agents for the newer medications. If a patient developed a spontaneous bleeding episode or perhaps needed emergency surgery and was on one of these newer medications, this may pose a problem. Your physician will meld those concerns into the decision process when potentially choosing one of these drugs.
If a patient is taking Coumadin or Jantoven and has not had any problems with the drug and is easily maintained within the appropriate therapeutic window, there may not be a compelling reason to switch their therapy. If, however, a patient cannot be appropriately dosed on Coumadin or Jantoven or has drug interactions that cannot be avoided, then one of these newer agents may be a perfect alternative.
There are also certain cardiac conditions such as those with mechanical heart valves or those with rheumatic mitral valve disease that may not be candidates for one of the newer agents. Since this is a very complex decision process as to which drug may be a better choice, I would encourage you to talk with your doctor if you have a condition that requires the use of warfarin to see if one of these newer medications might be a reasonable alternative.
Dr. Kenneth Tobin is a clinical assistant professor for the Department of Internal Medicine and director in the Chest Pain Center at the University of Michigan. His specialty is cardiology, with clinical interests in the association of patent foramen ovale and stroke, patent foramen ovale and migraine, preventive cardiology and echocardiography.
The University of Michigan Samuel and Jean Frankel Cardiovascular Center is a top-ranked heart and heart surgery program among Michigan hospitals. To learn more, visit our website at umcvc.org.