The threat is so serious that the American Heart Association is warning people with heart failure and their doctors that they need to closely watch what they take.
Five million Americans have heart failure, and the number is expected to rise as the population ages, says Robert L. Page II, PharmD, professor of clinical pharmacy at the University of Colorado School of Pharmacy. He led the group writing the statement.
People with heart failure take an average of seven prescription medications a day, as well as over-the-counter medicines and supplements, for heart failure and other conditions. Each additional medication increases the risk of side effects or dangerous drug interactions. Some may be serious enough to require going to the hospital.
The AHA has published a PDF file of the medications.
Here’s what you need to know.
Q: What did the report find?
"We found there are a large number of medicines which can cause or exacerbate heart failure,” Page says. “These are drugs used for diabetes, for pain, for psychiatric conditions, for cancer, and other conditions."
Besides prescription and over-the-counter medicines, he says, ''the other issue is with herbal and natural supplements."
Some products increase the risk of bleeding, while others can slow or speed up the heart rate too much.
To reach their findings, the researchers looked at package inserts for the medications and more than 300 published studies, as well as expert opinions. The researchers then created a lengthy list of prescription medicines, over-the-counter medicines, and supplements that could pose problems.
Page says there wasn’t as much research for supplements, and a lot of the data is based on studies done on animals.
The list is likely to surprise even health care providers, says Ron Litman, DO, medical director of the Institute for Safe Medication Practices. He praised researchers for using an “evidence-based” approach.
Q: Which prescription drugs and over-the-counter drugs may be particularly worrisome when it comes to heart failure?
Page says the big three, are:
"NSAIDs can cause retention of salt and water," says Michael Givertz, MD, professor of medicine at Harvard Medical School. "They can blunt or neutralize the beneficial effects of a diuretic, which heart failure patients take to get rid of fluids." They can also increase blood pressure, he says.
Drugs that have a lot of sodium aren't good for people with heart failure, who are told to limit it, Page says. For instance, the osteoporosis drug alendronate, an effervescent tablet, has 650 milligrams of sodium per tablet. Some antibiotics have high levels of sodium.
Q: Which supplements and ''natural'' remedies should heart failure patients especially avoid?
Watch out for products beginning with G, Page says. Among them, he says, are green tea, ginkgo, ginger, grapefruit juice or grapefruit, and garlic powder. These were found to interact with medicines often taken by heart failure patients. For instance, green tea can affect the way the blood thinner warfarin (Coumadin) works, the researchers found.
St. John's wort, a remedy for depression, can also interact with many heart drugs, the committee found. For instance, St. John's wort can lead to a buildup of the drug digoxin in the blood, and that can trigger an abnormal and fatal heart rhythm, Page says.
Q: How do some of these drugs and supplements worsen heart failure?
Some can damage heart muscle cells directly, Page says, or they can change how the heart muscle squeezes. Others can interact with heart failure medicines so the drugs don't work as well to treat the heart failure.
Q: Did the study look only at heart failure patients, or could the medicines cause a problem for those who don't have heart failure?
Although the study looked mainly at heart failure patients, some of the drugs could bring on heart failure, Page says. For instance, some chemotherapy drugs can be toxic to the heart and trigger heart failure. In those cases, Page says, the benefits of them must be weighed against the risk of heart failure.
A person at risk for heart failure might develop it while taking some medicines, Givertz says. If a medicine causes high blood pressure or changes in heart rate or rhythm, he says, that could bring on heart failure. Extra weight and a history of heart attack both increase the risk of developing heart failure.
Q: Are the problems reversible once the drug that led to the problem is stopped?
Not always, Page says. Sometimes the heart muscle is so damaged it's not reversible.
Q: What's the best advice for a heart failure patient?
Everyone with heart failure should have a ''captain'' of their medications. That might be their primary care doctor, their cardiologist, or another health care professional.
The captain should be aware of all the medicines and supplements a patient is taking, along with any potential for interactions. Health care providers should review and update the list at every visit. Doctors should not prescribe new medicines to treat side effects of other medicines, Page says.
People should get clearance from their doctor before starting any over-the-counter medicine or any supplement.
Litman says people should expect their doctors to think carefully about how a new medicine will interact with current medications. If a team is not in place, he says, you can request that someone on the health care team look at all the medicines you're tasking to be sure all are still needed and that there is no danger of interactions.