Millions of Americans have had a stent placed in an artery in the heart or suffer from acute coronary syndrome such as unstable angina or a heart attack. Most of these patients take a blood thinner to help prevent potentially dangerous clotting within the stent or arteries.
The most commonly used blood thinner is Plavix (clopidogrel), though there are now two newer medications – Effient (prasugrel) and Brilinta (ticagrelor) – that can be used to treat these conditions, as well. If you’re a person who has been prescribed Plavix, you may be wondering how the two newer drugs match up to this older, tried-and-true med.
Let’s start with one important similarity. All of these drugs, even the newest ones, carry an increased bleeding risk, but the level of risk does vary with each one.
Now to a direct comparison of the pros and cons of each medication.
Plavix, as the oldest medication (approved in 1997), is the most commonly used. But because it has to be processed and activated in the liver, it sometimes takes a while for Plavix to take effect. It can also have what experts call a “variable response” in patients, meaning that it’s more effective in some people than in others. Some people do not, in fact, respond to Plavix at all. Only a genetic test—which requires additional time and expense for the patient—can tell if a person has a variant on the CYP2C19 gene that affects the way Plavix works.
Effient (approved in 2009) has been found to be more effective than Plavix and it works more quickly because it doesn’t have to go through the metabolic pathway that Plavix does. There also haven’t been the same issues with poor response—or no reponse—to the drug that’s been found with Plavix, and there’s no need for genetic testing to see if the Effient will work.
However, a study published in the New England Journal of Medicine of 13,000 patients suggested that there are higher risks of internal bleeding—some fatal—with Effient. Some experts believe this increased bleeding risk basically cancels out the drug’s benefits.
Brilinta (approved in 2011) has been found to be more effective than Plavix, and it also begins working more quickly than this older drug because it also doesn’t have to be processed in the liver, like Effient. No genetic testing is required, since Brilinta isn’t affected by the gene variant that interferes with Plavix.
The downside of this, though, is that Brilinta wears off more quickly because the drug doesn’t bind to platelets permanently like Plavix and Effient. People must also take a low-dose aspirin (81 mg per day) along with Brilinta to get this greater level of effectiveness, though many people who take Plavix are also on a low-dose aspirin regimen already. Brilinta must be taken twice a day rather than once a day like Plavix. Some people also experience shortness of breath with Brilinta, particularly in the first few weeks of taking it, and they must be switched to one of the other two medications. Brilinta’s risks of major bleeding are slightly higher than those found with Plavix, but experts say the benefits far outweigh the risks.
One thing that may also weigh into you and/or your doctor’s choice of blood thinner is cost. Bristol-Myers Squibb’s patent on Plavix expires this month, and its availability may influence the choice of medication for some.
The bottom line, as with all discussions of medications, is to trust your doctor’s choice of medication for you. He or she will take in all the evidence available on both you and these drugs, including how cost plays into your treatment.
Sources: Pharmacy Made Simple; WebMD; NEJM; Drugs.com; U.S. Food and Drug Administration
Ph.D, with 20 years experience writing both creatively and in the fields of technical/science/health writing.