Polypharmacy is the simultaneous use of multiple medications by patients to treat one or more conditions. While there is no standardized threshold to define "multiple medications," literature frequently refers to polypharmacy when describing a situation where patients take at least five medications.
Such situations are becoming increasingly common. A Journal of the American Medical Association investigation revealed that the prevalence of polypharmacy (in this case defined as the use of five or more prescription drugs) increased from an estimated 8.2% in 1999-2000 to 15% in 2011-2012. Statistics cited in an UpToDate report indicate that an estimated 50% of Medicare beneficiaries receive five or more medications and among ambulatory older adults with cancer, 84% receive five or more and 43% receive 10 or more medications. The report notes that increasing numbers of drug therapies have been associated with increased adverse drug event and hospital admission risk.
Here are six ways polypharmacy creates challenges for patients to adhere to a medication regimen.
1. Complex dosing schedule
As the number of medications increases, the complexity of the dosing schedule will as well. Consider the following possible dosing scheduling for five medications:
- Medication #1: Once daily
- Medication #2: Once every 12 hours
- Medication #3: Four times a day (morning, noon, evening, bedtime)
- Medication #4: Once a week
- Medication #5: Three times a week
Even with a calendar identifying when a patient should take these medications, it would not be surprising for a patient to experience occasional poor compliance or confusion with dosing. Whenever a new medication is added or a regimen undergoes a different type of change (e.g., frequency, dosage, timing), which is fairly common for individuals taking multiple medications, the schedule will need to change as well. This introduces another level of complexity. For individuals with depression or memory issues or low health literacy, a challenging dosing schedule will be even more difficult to follow.
2. Medication instruction confusion
All medications come with directions, whether on a medicine label or provided as a printout from the prescriber. These directions spell out the amount of medicine to take, how to take it, dosing schedule, and when not to take the drug. When patients are taking more types of medications, this increases the potential for mixing up the rules for these medications, particularly when multiple medications appear the same (e.g., inhalers, injections, similarly colored pills) or have a similar sounding or looking name (i.e., look-alike and sound-alike drugs).
3. Side effects
The side effects associated with some medications can create obstacles to adherence compliance. For example, medications that lead to fatigue and lethargy may cause a patient to sleep through a dosing period while medications that cause memory loss can contribute to a patient forgetting when to take medications or believing they have not yet taken a medication, which can lead to double (or more) dosing. If a medication makes a patient nauseous, the individual may not want to take another prescribed medication that requires drinking or eating.
While prescribers have tools that can help predict possible adverse drug reactions between medications, predicting reactions becomes more difficult when more medications must be factored in. Polypharmacy raises the risk that medications taken together will lead to undesirable (and potentially harmful) interactions. If patients experience bad reactions to medications, they may attempt to modify their regimen to avoid repeating the experience.
5. High cost
More medication usually translates to greater cost for patients. Depending upon the type of medication, this cost can quickly add up to a lot of money that must be spent on a recurring basis (i.e., refills). If finances are a concern, patients may choose not to fill or refill a prescription or choose to postpone doing so.
As a CVS Caremark survey of more than 2,400 retail pharmacists found, 62% believe the high cost of drugs is the top reason why Americans do not take medication as prescribed, with the participating pharmacists estimating nearly one-third of their customers choose not to fill a prescription due to its price every year.
6. Fill and refill frequency
Filling and refilling prescriptions can prove difficult for many patients. Contributing factors include the ability for patients to move, travel, and visit a pharmacy; the need to remember to pick up prescriptions; and the previously discussed cost of medications. These challenges are further magnified when patients are expected to fill and then refill numerous medications, especially when the timing of filling and refilling medications do not align in such a manner to keep the number of trips to a pharmacy down to a minimum. If patients do not have the ability to get to a pharmacy or are not feeling up to making such a trip, this can cause a lapse in adherence that will continue until the prescriptions are filled.