Many older people take a range of medications.
A study led by Dr. Dima Qato, Ph.D., from the University of Illinois at Chicago College of Pharmacy, found that, in 2005-2006, over 50 percent of adults in the United States aged 57-85 years were taking five or more medications, whether prescription, over-the-counter (OTC) remedies, or dietary supplements.
Around 30 percent of people surveyed were using five or more prescription drugs, and over 58 percent were taking at least one medication that they did not need.
A recent study by Dr. Qato's team, published in JAMA Internal Medicine, shows that the problem is growing.
By 2010-2011, the percentage of Americans using five or more prescription drugs alone had risen to 35.8 percent.
Appropriate and inappropriate medication
People with complex medical needs might need a range of medications, or they may take one drug to counter the adverse effects of another.
However, inappropriate use of several medicines can be both wasteful and dangerous.
According to Health Research Funding, polypharmacy is responsible for 28 percent of all hospital admissions, and it is the fifth leading cause of death in the U.S.
Inappropriate polypharmacy can result when:
- A patient continues taking drugs that are no longer needed, or at a dose that is no longer suitable
- A drug is not achieving its therapeutic aim
- The combination of therapies leads to adverse reactions or interactions
- The patient does not follow the physician's instructions.
Medical News Today asked Dr. Qato whether family doctors and specialists sometimes prescribe conflicting medications.
She told us: "Patients may be prescribed medications from multiple prescribers, especially if they suffer from multiple chronic conditions, for example, rheumatoid arthritis, heart disease, and diabetes. Some, or all, of their doctors may not be aware of all the medications prescribed or used."
"For this reason, patients should tell all their doctors, especially their primary care physician, all the medications and supplements they use, even if they weren't prescribed by them."
Dr. Dima Qato, Ph.D.
Older people are more affected
Polypharmacy affects older people especially, as they tend to have more complex needs.
In the U.S., people aged 65-69 years take an average of around 14 prescription drugs, rising to 18 by the time they are 80-84 years old.
Older people can have a hard time working out which drug to take and when.
Dr. Qato's team found that people aged 62-85 years often use a combination of antiplatelets, anticoagulants, statins, and nonsteroidal anti-inflammatories (NSAIDs).
These can all lead to serious drug-drug interactions, increasing the risk of health problems.
Older people can also be more susceptible because their needs and bodies may change more quickly over time. As they become more frail, doses and treatments can affect them differently.
Those with dementia can become confused or forgetful about their medication, putting them at risk of overdosing or of not understanding the dosage and times of regular medications.
Research published in Toxicology International suggests prescribing drugs that can be delivered through once-daily dosage.
Supplements: Good for the health?
A growing number of patients are using herbal and dietary supplements, without realizing that they may interact with existing drugs.
- In 2007-2010, 13.9 percent of Americans aged 18 years and over used five or more prescription drugs
- 47.5 percent of people aged over 65 used five or more prescription drugs
- 3.9% of those aged over 65 years used no medications.
Dr. Qato's team found that the percentage of people using five or more medications or supplements of any sort rose from 53.4 percent to 67.1 percent from 2005-2006 to 2010-2011.
OTC drug usage fell from 44.4 percent to 37.9 percent, but use of dietary supplements rose from 51.8 percent to 63.7 percent. Most popular were multivitamins, mineral supplements, and calcium.
At the same time, the risk of a major drug interaction rose from around 8.4 percent to 15.1 percent. The researchers believe the use of supplements may play a role.
A common, potentially harmful combination involved preventive cardiovascular drugs and supplements.
The authors conclude:
"The unsafe use of multiple medications among older adults is a growing public health problem. Therefore, healthcare professionals should carefully consider the adverse effects of commonly used prescription and nonprescription medication combinations when treating older adults and counsel patients about these risks."
Herbs can also cause interactions. MNT previously reported that rosemary, in large quantities, can interact with anticoagulants, ACE inhibitors, diuretics, and lithium - a treatment for bipolar disorder.
Warning signs of inappropriate drug combinations
MNT asked Dr. Qato how people can know if they are taking an unsuitable combination.
She told us:
"The warning signs depend on the drug combination. In older adults, the most commonly used interacting combinations involved statins, amlodipine (an antihypertensive), NSAIDs, blood thinners, omega-fish oil, niacin supplements and omeprazole (a proton pump inhibitor). Most of these combinations may increase risk for bleeding, muscle weakness, renal failure or blood clot formation, which may be fatal."
Observable signs that a person is taking an unhealthy combination of drugs include:
- Loss of appetite, constipation, diarrhea, or incontinence
- Tiredness, sleepiness, or decreased alertness
- Confusion and hallucinations
- Falls, weakness, and dizziness
- Depression, anxiety, or excitability
- Skin rashes.
These can resemble signs of aging or other conditions, but they may be due to drug-drug or drug-disease interactions.
What can be done?
The more medications a person uses, the higher the chance that the drugs will interact. Research indicates that a patient taking between five and nine medications has a 50 percent chance of an adverse interaction, rising to 100 percent with 20 or more medications.
Pharmacies and carers can help older people to organize their medications.
Healthcare providers should make sure that all drugs are prescribed to treat specific problems, and they should check that the drugs are meeting those needs, or discontinue them.
Discussing and agreeing the medications with the patient can increase the chance of them keeping to the instructions and reduce the risk of interactions.
Commenting on Dr. Qato's recent research, Dr. Michael A. Steinman, of the University of California-San Francisco, calls for systems to be set up that will:
- Support the ongoing monitoring of drug use
- Ensure that drug combinations are reasonable
- Continuously assess the benefits and harms of the drugs being taken
- Review patients' ongoing needs.
Dr. Qato told MNT that she would like to see stronger regulation of supplements by the U.S. Food and Drug Administration (FDA), and that the products should not be so easily accessible to the public, "especially because we know very little about their safety."
"Prescribers should ask patients about all the medications and supplements they use and patients should also inform their prescriber. Supplements often offer limited, if any, benefits and should be avoided unless they are prescribed. This is especially important in patients taking prescription and over-the-counter medications, which may interact with supplements."
She urges people to check with their pharmacist before buying any OTC product or supplement, to ensure it is safe to use with their other medications.
A research letter published in JAMA Internal Medicine reports that 42.3 percent of patients do not tell their physician about their use of complementary therapies because they do not believe the doctor needs to know.
Patients should be encouraged to share this kind of information.
MNT asked Dr. Qato how patients can prevent adverse effects due to conflicting medications.
Her advice is to stay informed about the risks involved with all the types of medication they are taking.
"Inform all your doctors and pharmacist about all the medications and supplement you use. Before you purchase or start taking a new medication or supplement, make sure it is safe to take with all the medications your are currently taking."
Dr. Dima Qato, Ph.D.