“Polypharmacy” is the clinical term for drug-drug interactions (DDIs) in clinical pharmacy

This article appeared in a recent issue of the New York Times.

Each drug can be considered as “an environmental chemical”, with regard to studying one drug’s effect on a patient, or the patient’s response to that one drug.  REPOSTED BY DwN

The Dangers of ‘Polypharmacy,’ the Ever-Mounting Pile of Pills


Paula Span-APRIL 22, 2016


Dr. Caleb Alexander knows how easily older people can fall into so-called polypharmacy. Perhaps a patient, like most seniors, sees several specialists who write or renew prescriptions.

A cardiologist puts someone on good, evidence-based medications for his heart,” said Dr. Alexander, co-director of the Johns Hopkins Center for Drug Safety and Effectiveness. “An endocrinologist does the same for his bones.”

And let’s say the patient, like many older adults, also uses an over-the-counter reflux drug and takes a daily aspirin or a zinc supplement and fish oil capsules.

Pretty soon, you have an 82-year-old man who’s on 14 medications,” Dr. Alexander said, barely exaggerating.

Geriatricians and researchers have warned for years about the potential hazards of polypharmacy, usually defined as taking five or more drugs concurrently. Yet it continues to rise in all age groups, reaching disturbingly high levels among older adults.

It’s as perennial as the grass,” Dr. Alexander said. “The average senior is taking more medicines than ever before.”

Tracking prescription drug use from 1999 to 2012 through a large national survey, Harvard researchers reported in November that 39 percent of those over age 65 now use five or more medications — a 70 percent increase in polypharmacy over 12 years.

Lots of factors probably contributed, including the introduction of Medicare Part D drug coverage in 2006 and treatment guidelines that (controversially) call for greater use of statins.

But older people don’t take just prescription drugs. An article published in JAMA Internal Medicine , using a longitudinal national survey of people 62 to 85, may have revealed the fuller picture.

More than a third were taking at least five prescription medications, and almost two-thirds were using dietary supplements, including herbs and vitamins. Nearly 40 percent took over-the-counter drugs.

Not all are imperiled by polypharmacy, of course. But some of those products, even those that sound natural and are available at health food stores, interact with others and can cause dangerous side effects.

How often does that happen? The researchers, analyzing the drugs and supplements taken, calculated that more than 8 percent of older adults in 2005 and 2006 were at risk for a major drug interaction. Five years later, the proportion exceeded 15 percent.

We’re not paying attention to the interactions and safety of multiple medications,” said Dima Qato, the lead author of the JAMA Internal Medicine article (Dr. Alexander was a co-author) and a pharmacist and epidemiologist at the University of Illinois at Chicago. “This is a major public health problem.”

She was stunned to discover, for instance, that the use of omega-3 fish oil supplements had quadrupled over five years. Her research suggests that almost one in five older adults now takes them.

Users probably believe fish oil helps their hearts. But Dr. Qato pointed out fish oil capsules lacked regulation and evidence of effectiveness, and can cause bleeding in patients taking blood thinners like warfarin (brand name: Coumadin).

Though drug interactions can occur in any age group, older people are more vulnerable, said Dr. Michael A. Steinman, a geriatrician at the University of California, San Francisco, who wrote an accompanying commentary.

Most have multiple chronic diseases, so they take more drugs, putting them at higher risk for threatening interactions.

The consequences can also be more threatening. Say a drug makes older patients dizzy.

They’re more prone to fall, because they don’t have the same reserves of balance and strength” as the young or middle-aged, Dr. Steinman said. “And if they do fall because they’re dizzy, they’re more likely to get hurt.”

Some common combinations that cropped up in the study and could spell trouble: aspirin and the anti-clotting drug clopidogrel (Plavix), both blood thinners that together increase the risk of bleeding with long-term use; aspirin and naproxen (Aleve), over-the-counter drugs that when combined can cause bleeding, ulceration or perforation of the stomach lining.

Dr. Qato recalled reviewing the medications of a 67-year-old man taking both the cholesterol drug simvastatin (Zocor) and the blood pressure medication amlodipine (Norvasc) — the most common combination of interacting drugs that emerged in her study.

Statins, along with their cholesterol-lowering properties, can cause muscle pain and weakness; Norvasc heightens that risk. A different blood pressure drug — there are many alternatives — would be a safer choice, Dr. Qato said. Yet almost 4 percent of the older adults in her study took both drugs.

Moreover, though her patient wasn’t experiencing problems, he was also taking garlic and omega-3 supplements, which can interact with prescription medications.

Did you tell your doctor you were on them?’” Dr. Qato recalled asking. “He said, ‘No, why should I? If it was important, why didn’t he ask me?’”

A reasonable question. A recent study in JAMA Internal Medicine, however, found that more than 42 percent of adults didn’t tell their primary care doctors about their most commonly used complementary and alternative medicines, including a quarter of those who relied most on herbs and supplements.

Usually, that was because the physicians didn’t ask, and the patients didn’t think they needed to know; in a few cases, doctors had previously discouraged alternative therapies, or patients thought they would.

And they might, especially for older patients with complex regimens. “I’m not a big fan of supplements,” Dr. Alexander tells patients taking lots of vitamins, supplements and herbal remedies.

I think the vast majority of evidence raises serious questions about their effectiveness or, in some cases, their safety. They’re less well regulated than prescription medications. I think you’d be better off stopping them.”

Patients often resist, he said, and “they’re the captain of their own ship.” So he explains the risks and benefits, and negotiations ensue.

Often, though, patients don’t know that a daily aspirin, Prilosec OTC or fish oil can interact with other drugs. Or they’re confused about what they’re actually taking.

Dr. Steinman recalled asking a patient to bring in every pill he took for a so-called brown bag review. He learned that the man had accumulated four or five bottles of the same drug without realizing it, and was ingesting several times the recommended dose.

Ultimately, the best way to reduce polypharmacy is to overhaul our fragmented approach to health care. “The system is not geared to look at a person as a whole, to see how the patterns fit together,” Dr. Steinman said.

In the meantime, though, patients and families can ask their physicians for brown bag reviews, including every supplement, and discuss whether to continue or change their regimens. Pharmacists, often underused as information sources, can help coordinate medications, and some patients qualify for medication reviews through Medicare.

We spend an awful lot of money and effort trying to figure out when to start medications,” Dr. Alexander said, “and shockingly little on when to stop.”

This entry was posted in Pharmacogenetics. Bookmark the permalink.