What is deprescribing?
Deprescribing is the planned and supervised process of dose reduction or stopping medication that can cause harm or no longer be of benefit. Often, older adults are placed on a medication for a given reason that no longer exists (potassium supplement given during an acute illness that is no longer needed but never discontinued), therapeutic effect is no longer evident (continued use of cholinesterase inhibitors in end-stage dementia), or the medication should not have been prescribed in the first place (PPI prescription when starting a medication, such as metformin, known for GI upset). This can lead to inadvertent polypharmacy.
A worldwide practice, deprescribing informs the clinician and patient to reconsider if medications are helpful and necessary. Backing off a medication when the dosage is too high or stopping a medication that is no longer needed is an important part of “good prescribing.”
Related: Deprescribing in Older Adults: Doing More by Doing Less
What is different in prescribing medications to older adults?
Pharmacodynamics (PD), or what a drug does to the body, includes its mechanism of action, remain unchanged over the lifespan. However, pharmacokinetics (PK), or what the body does to the drug, including absorption, distribution, metabolism (biotransformation) and excretion, differ as a person ages. Additional PK-influencing factors include birth gender assignment, age, acute and chronic health problems, as well as kidney and hepatic function.
What are some age-related changes that nurse practitioners need to consider when prescribing for older adults?
The human body is at its peak functioning around age 30. By the time older adults are 70 to 80 years of age, many changes have occurred that affect how the body responds to medications. Some of these age-related changes include:
- Percent body weight as water. Older adults have lower fluid reserves and can dehydrate easily. This is important when considering diuretics or other medications that can influence total body water.
- Percent body weight as fat. For an older adult with a consistent body weight, the percentage of body weight as fat will increase with age. This is natural so the body has more calories in store. This allows for a greater volume for lipophilic (fat-soluble) drugs, such as the benzodiazepines, to be stored, potentially increasing the half-life of the medication.
- Serum albumin average. The liver shrinks in size with normative aging, leading to lower levels of albumin production even in the presence of adequate nutrition. When prescribing highly-protein (albumin) bound drugs, such as warfarin and carbamazepine, this age-related change usually leads to the patient needing progressively lower doses to reach the same clinical effect.
- Relative kidney weight. A decrease in kidney weight and resulting reduction in renal function, leads to an increase in the time needed to offload the majority of medications. Of course, this normative change is often coupled with chronic kidney disease. These changes often lead to the need to adjust medication doses.
- Relative hepatic blood flow. As normative, age-related changes in the heart progress, cardiac output is reduced. One of the end-products is that drug-bio transforming/metabolizing enzymes are not as active as they were as a younger adult. As with the renal changes, this often leads to the need for lower drug doses in the older adult.
What is the Beers Criteria?
The Beers Criteria is a list of potentially inappropriate medications for usage in older adults. This document is updated approximately every three years by the American Geriatrics Society and is a great resource for nurse practitioners to be better informed the risks of certain medications in older adults. The medication list and guidelines are available here.
In prescribing medications that have systemic anticholinergic effects, what are select concerns in older adults?
One important consideration for nurse practitioners prescribing to older adults is the risk of medications with systemic anticholinergic effects. Examples include first-generation antihistamines such as diphenhydramine (Benadryl) and select overactive bladder (OAB) medications such as oxybutynin (Ditropan).
In older adults, the use of these medications carries increased risks of cognitive alterations, urinary retention, constipation, visual disturbance, and hypotension. These adverse effects could lead to polypharmacy, adding more medications to reverse the problematic anticholinergic impact of these medications, and the risk of delirium.
The prescriber should keep in mind that there are nearly always alternative therapeutic options that have little to no systemic anticholinergic effect. Examples include, for the treatment of OAB, prescribing mirabegron (Myrbetriq) rather than oxybutynin, and for allergic rhinitis symptoms, advice on using a 2d generation antihistamine such as loratadine (Claritin) rather than diphenhydramine (Benadryl).
How can nurse practitioners apply principles of deprescribing?
When a nurse practitioner recognizes that medication likely should not have been started in the first place, good prescribing dictates discontinuing this medication. Deprescribing medications in this situation should follow certain protocols depending on the medication. There are resources on Deprescribing Guidelines and Algorithms available for nurse practitioners available to help deprescribe safely.
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