Americans Mix It Up Too Much With Drugs, Study Finds

More people than ever are taking bunches of medications and supplements that could interact in ways that make them worse instead of better, researchers reported Monday.

They found that one in six older adults regularly use potentially deadly combinations of prescription drugs, over-the-counter products and dietary supplements — double the number that did so just five years ago.

Image: Prescription drugs are prepared for a customer at a pharmacy
Prescription drugs are prepared for a customer at a pharmacy on June 16, 2003 in Hollywood, Fla. Joe Raedle / Getty Images file

And that's in spite of study after study warning against taking too many drugs at the same time — and especially against taking supplements without checking for potential interactions.

"These findings suggest that the unsafe use of multiple medications among older adults is a growing public health problem," Dima Qato of the University of Illinois at Chicago and colleagues wrote in their report.

"Approximately one in six older adults may be at risk for a major drug-drug interaction," they wrote in their report, published in the Journal of the American Medical Association's JAMA Internal Medicine.

Qato's team studied 2,351 adults with an average age of 71 in 2005-2006 and compared them to another 2,206 people about the same age in 2010-2011. They were interviewed in their homes to get good details of the drugs and supplements they used.

In 2005, 30.6 percent said they were taking five or more drugs. In 2011, that figure rose to 35.8 percent of the adults. And when supplements and nonprescription drugs were added, 67 percent of older adults were taking five or more medications in 2011, compared to 53 percent in 2006.

It's not surprising. High blood pressure, high cholesterol, diabetes, arthritis and other chronic conditions are extremely common in the U.S., and medications to help control them work well. For high blood pressure in particular, patients are often prescribed a cocktail of drugs, including diuretics, beta-blockers and ACE inhibitors.

A third of U.S. adults have high blood pressure so that adds up to a lot of drugs.

And cholesterol-lowering statin drugs — including Lipitor, Crestor and Zocor — are extremely popular. They're prescribed to about 15 percent of American adults.

They have been shown to cut the risk of heart attacks and stroke.

The numbers show that popularity. The percentage of people taking simvastatin, sold under the brand name Zocor, doubled from 10.3 percent in 2006 to 22.5 percent, Qato's team found.

But sometimes people mix drugs they shouldn't. One example is the anti-blood clot drug clopidogrel, and another is the widespread use of over-the-counter drugs such as aspirin and ibuprofen, called non steroidal anti-inflammatory drugs or NSAIDs. They treat pain, can reduce the risk of a heart attack and can even lower the risk of some cancers.

Some Supplements Can Interfere With Prescription Medicine, Study Finds 2:10

NSAIDs can also cause stomach bleeding. And their blood-thinning effects can push another drug's therapeutic benefits into dangerous territory.

"Most of the interacting regimens we identified involved statins, antiplatelets (e.g, clopidogrel and aspirin), NSAIDs, or omega-3 fish oils, which may not only lead to adverse drug events due to drug-drug interactions but also worsen cardiovascular risk," the researchers wrote.

For example, combining clopidogrel in combination with NSAIDs or omeprazole, an anti-reflux drug, can raise the risk of heart attack or internal bleeding.

"However, according to our analyses, approximately 1.8 percent of older adults (or 1 million) regularly use clopidogrel in interacting combinations," they wrote.

And despite many high-profile reports showing that taking multivitamins is a waste of time and may even be harmful, the percentage of people taking them rose from 29 percent to 35 percent. Numbers of people taking fish oil shot up from about 5 percent in 2006 to nearly 19 percent in 2011.

"The almost four-fold increase in the use of omega-3 fish oils over a five-year period is particularly noteworthy considering their limited cardiovascular benefits," the team wrote.

And a second study in the same journal found that a quarter of adults don't tell their doctors when they use supplements.

"This is mostly because physicians do not ask and because patients do not think their health care providers need to know," Dr. Michael Steinman of the University of California, San Francisco, wrote in a commentary on both studies.

"There are many older adults who would be healthier if they threw away half of their medications. Yet there are people with multiple chronic diseases who can benefit from multidrug therapy," Steinman, a specialist in geriatrics, wrote.

"We are winging it, and patients' medication regimens get bloated with unnecessary, ineffective, and harmful medications, despite our best intentions."

It's possible for the medical system to set up systems that would do a better job of watching what patients take, Steinman said.

"First, we need a comprehensive, portable, and truly informative medication list that the patient helps to maintain. This list would comprise all of a patient's medications, including over-the-counter and alternative therapies," he said.

"Second, we need a team approach to monitoring medication effectiveness and adverse effects. Consider the success of warfarin clinics. Pharmacists, nurses, and other health care professionals can be creatively engaged to systematize the process of medication monitoring and follow-up, complementing the role of the physician," Steinman added.

"Third, we need real patient engagement, supported by the whole health care team. This includes the targeted use of health coaches, who have been shown to markedly improve outcomes by helping patients communicate with and assert themselves to their physicians."

Sometimes it's a good thing if patients are taking many drugs, Steinman said.

"Numbers are not the enemy. Unnecessary, ineffective, and harmful prescribing is."