New study finds that 75 percent of patients taking popular blood-thinners are getting wrong dose

November 6, 2012

Cardiology researchers at the Intermountain Medical Center Heart Institute have found that approximately 75 percent of patients taking two common blood-thinning drugs may be receiving the wrong dosage levels, according to a new study.

This could put them at risk for serious problems like uncontrolled bleeding or developing blood clots.

Millions of Americans with take one of the two drugs— () and prasugrel (Effient)—to prevent harmful blood clots that can cause a stroke or . Current guidelines recommend that all patients take the same standardized dose. But in this new study of 521 patients, researchers at the Intermountain Medical Center Heart Institute found that dose is not effective for all patients.

"There's a , an appropriate range for each patient. But we found that not many people are falling into that range," said Brent Muhlestein, MD, a cardiac researcher at the Intermountain Medical Center Heart Institute.

Dr. Muhlestein is presenting the group's findings on Nov. 6 at the Scientific Sessions 2012 in Los Angeles.

"We showed that by performing a simple to see whether or not the blood is clotting properly, we can determine whether patients are getting an appropriate, individualized dose of the medications," he says. "The test is easy to perform, but not widely used."

The Intermountain Medical Center Heart Institute study could help lead to personalized treatment and improved results for millions of people taking the drugs. It may also help cut pharmacy bills for many patients. The annual cost for one of the medications is more than $1,800. Finding the lowest effective dose for those patients could conceivably cut their bill in half.

Major findings of the study show that:

  • Half of patients taking clopidogrel were getting too little of the drug to prevent clotting most effectively. A quarter were getting too much. Only a quarter were getting an accurate dose.
  • Half of patients taking prasugrel are getting too much of the drug, which could lead to dangerous bleeding. A quarter were getting too little. Only a quarter are getting the appropriate dose.
The researchers also discovered that common indicators like age, gender, cholesterol levels, and history of heart problems were not good predictors for how a person would react to the drugs.

"That means there's not an easy way to predict how a person will react to these drugs. But the blood test is very effective," said Dr. Muhlestein. "In fact, a physician could have the test machine on his or her desk and perform the test right there in the office."

Explore further: Low-dose daily aspirin enough to help heart attack patients: study

Related Stories

Low-dose daily aspirin enough to help heart attack patients: study

March 26, 2012
(HealthDay) -- Heart attack patients who take either a high or low dose of aspirin daily have the same level of protection against another heart attack or other cardiovascular events such as stroke, according to a new study. ...

Researchers find safer way to use common but potentially dangerous medication

February 29, 2012
A team of global scientists, led by researchers at Intermountain Medical Center in Salt Lake City, has developed a safer and more accurate way to administer warfarin, one of the most commonly prescribed but also potentially ...

Heart patients who take vitamins less likely to take medication as prescribed, according to study

November 14, 2011
Atrial Fibrillation patients who are prescribed the powerful blood thinner warfarin often take it with vitamins or supplements that can hamper its effectiveness, or skip doses completely, increasing their risk for stroke, ...

Plavix's new generic status could be boon for patients

May 15, 2012
(HealthDay) -- The blockbuster drug Plavix (clopidogrel), used to prevent clotting in some heart patients, will go off patent in the United States on Thursday, making it considerably more affordable.

New study links excessive amounts of vitamin D to onset of atrial fibrillation

November 16, 2011
While previous studies have linked vitamin D deficiency to an increased risk for cardiovascular disease, new research at the Intermountain Medical Center Heart Institute shows that too much vitamin D can lead to the onset ...

Anti-clotting drugs yield similar results

August 26, 2012
The first trial to study patients with acute coronary syndrome who do not undergo coronary stenting or bypass surgery found no significant difference between two anti-clotting drugs – prasugrel and clopidogrel – in preventing ...

Recommended for you

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries

Heart study finds faulty link between biomarkers and clinical outcomes

July 14, 2017
Surrogate endpoints (biomarkers), which are routinely used in clinical research to test new drugs, should not be trusted as the ultimate measure to approve new health interventions in cardiovascular medicine, according to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.