Medications for Older Adults
Aging changes how the body processes medications, increases the risk of drug interactions, and creates unique challenges in managing multiple prescriptions. This guide helps older adults and their caregivers navigate medication management safely.
How Aging Changes Drug Processing
The human body changes substantially with age, and many of these changes affect how medications work and how they should be dosed. Understanding these changes helps explain why medications that are safe for a 40-year-old may need to be dosed differently — or avoided entirely — in a 75-year-old.
Kidney Function
The kidneys filter drugs and their byproducts out of the bloodstream. Kidney function naturally declines with age — by age 70, most people have approximately 50% of the kidney function they had at age 30, even if they have no kidney disease.
This matters because many drugs are primarily eliminated through the kidneys. If the kidneys are clearing a drug more slowly, it builds up to higher concentrations in the body and stays there longer. Drugs that are normally safe at standard doses can accumulate to toxic levels in someone with reduced kidney function.
Common drugs that require dose adjustments based on kidney function include: - Metformin (diabetes): Not recommended when kidney function falls below a certain threshold due to risk of a rare but serious complication - Certain antibiotics (especially fluoroquinolones, aminoglycosides): Dose and interval adjustments needed - Gabapentin and pregabalin: Accumulate with reduced kidney function, increasing sedation risk - NSAIDs (ibuprofen, naproxen): Can further reduce kidney blood flow, worsening function
Your prescriber should check your kidney function (via a blood test measuring creatinine and eGFR) before prescribing or adjusting medications that are renally cleared, particularly in older adults.
Liver Function
The liver is the primary site of drug metabolism. Although liver function does not decline as predictably with age as kidney function, several age-related changes affect drug metabolism: - Reduced liver blood flow means drugs pass through the liver more slowly - Lower levels of certain enzymes in older livers - Decreased liver mass
These changes mean some drugs are cleared from the body more slowly. Drugs that are highly metabolized by the liver — including many benzodiazepines, opioids, and some antidepressants — can accumulate to higher levels in older adults even at standard doses.
Body Composition Changes
As people age, body fat increases and lean muscle mass and total body water decrease. These changes affect drug distribution:
- Water-soluble drugs: Because older adults have less total body water, the same dose of a water-soluble drug produces higher concentrations. This includes drugs like alcohol, digoxin, and lithium.
- Fat-soluble drugs: Because older adults have more body fat, fat-soluble drugs (like diazepam) distribute into a larger volume and have longer durations of action — they stay in the body longer.
Additionally, older adults typically have lower levels of blood proteins (particularly albumin) that bind drugs in the bloodstream. With less protein bindingProtein Binding The reversible binding of drugs to plasma proteins (primarily albumin). Only the unbound (free) fraction of a drug is pharmacologically active. Highly protein-bound drugs can be displaced by other dru
polypharmacyPolypharmacyThe concurrent use of multiple medications by a patient, typically defined as five or more drugs. Polypharmacy increases the risk of drug interactions, adverse effects, medication errors, and poor adh
-the-challenge-of-many-medications">Polypharmacy: The Challenge of Many Medications
Polypharmacy — typically defined as taking five or more medications simultaneously — is increasingly common among older adults. Approximately 40% of older adults in the U.S. take five or more prescription drugs, and when OTC drugs and supplements are included, the numbers are even higher.
Polypharmacy increases risk in several ways: - Drug-drug interactions: The more medications you take, the more possible interactions exist. With 5 drugs, there are 10 possible two-drug combinations. With 10 drugs, there are 45. - Prescribing cascade: A side effect of one drug is mistakenly identified as a new disease and treated with another drug, which has its own side effects — creating a cycle of ever-increasing medications. - Nonadherence: Managing complex medication regimens is cognitively demanding. The more medications, the easier it is to make errors. - Adverse drug events: Older adults are twice as likely to be hospitalized due to adverse drug events as younger adults.
The goal is not necessarily to minimize the number of medications, but to ensure that every medication has a clear indication, an appropriate dose, and a favorable benefit-to-risk balance for that specific person.
The Beers Criteria: Medications to Be Cautious About
The American Geriatrics Society Beers Criteria is a list of medications that are potentially inappropriate for use in older adults, updated regularly by a panel of experts. The criteria include drugs that: - Have a high risk of adverse effects in older adults - Have alternatives that are safer for this population - May be appropriate in some situations but require careful consideration
Some notable categories on the Beers Criteria:
First-generation antihistamines (diphenhydramine/Benadryl): The strong anticholinergic effects cause confusion, constipation, urinary retention, and sedation — all significant concerns in older adults.
Benzodiazepines (diazepam, lorazepam, alprazolam): Significantly increased risk of falls, sedation, cognitive impairment, and motor vehicle accidents. Long-acting benzodiazepines like diazepam are especially concerning because they accumulate.
Sleep medications (zolpidem/Ambien, eszopiclone/Lunesta): Fall risk, cognitive effects, and complex sleep behaviors. Short-term use only if at all.
Muscle relaxants (cyclobenzaprine, methocarbamol): Sedating and poorly tolerated; evidence for effectiveness in older adults is limited.
Tricyclic antidepressants (amitriptyline, doxepin): Anticholinergic effects and sedation; safer antidepressants are generally preferred.
NSAIDs (ibuprofen, naproxen): Gastrointestinal bleeding risk increases substantially with age; kidney function impact is also a concern.
This does not mean these drugs are never appropriate — only that they require careful evaluation of whether the benefit justifies the risk in older adults specifically, and whether safer alternatives exist.
Fall Risk and Medications
Falls are the leading cause of injury-related death in Americans over age 65, and many medications contribute meaningfully to fall risk. High-risk categories include:
- Sedatives and hypnotics: Direct sedation and impaired balance
- Opioids: Sedation, dizziness, and impaired coordination
- Benzodiazepines: Sedation, muscle relaxation, impaired balance
- Antihypertensives: Can cause orthostatic hypotension — a drop in blood pressure when standing up quickly — causing dizziness and falls
- Antidepressants (especially tricyclics and SSRIs): Multiple mechanisms including sedation and orthostatic changes
- Anticholinergics: Cognitive effects, sedation, blurred vision
If an older adult is falling or has fall risk, medication review should be part of the evaluation. Often, stopping or reducing certain medications is more beneficial than adding a new drug.
Cognitive Effects
Some medications can cause or worsen confusion, memory problems, and delirium in older adults — a condition sometimes called drug-induced cognitive impairment. This is particularly relevant because: - Cognitive changes may be misattributed to dementia progression - Older adults with mild cognitive impairment are more vulnerable to drug-induced effects - The symptoms often resolve when the offending medication is stopped or dose is reduced
Drug classes with significant anticholinergic effects are a particular concern: antihistamines, tricyclic antidepressants, bladder medications (oxybutynin), anti-nausea medications (promethazine), and some antipsychotics all have anticholinergic properties that can impair cognition.
If you or a family member experiences new confusion, memory lapses, or behavioral changes after starting a new medication, medication-induced effects should be considered.
Adherence Challenges in Older Adults
Older adults face specific barriers to medication adherenceMedication Adherence The extent to which a patient takes medications as prescribed — at the correct dose, frequency, and duration. Poor adherence affects approximately 50% of patients with chronic diseases and is a leadin
Strategies that help: - Blister packs or bubble packs from the pharmacy (organized by day and time) - Pill organizers with day/time compartments - Medication alarm apps or smart pillbox devices - Medication synchronization (all refills on the same day) - Pharmacist-dispensed compliance packaging
The Medication Review Strategy
A comprehensive medication review is one of the most beneficial things an older adult can do — ideally on a regular basis (at least annually, or after any significant change in health status, hospitalization, or new medication addition).
During a medication review: - List every medication including OTC drugs and supplements - Review every medication for its current indication — is there still a reason to take it? - Check for drugs that may have been prescribed for side effects of other drugs (prescribing cascade) - Assess doses for appropriateness given current kidney/liver function - Look for drug-drug and drug-disease interactions - Screen against Beers Criteria or similar tools
Ask your prescriber or pharmacist about Medication Therapy Management (MTM) services — these are comprehensive reviews typically covered by Medicare Part D for qualifying patients.
Strategies for Safer Medication Use
Keep an updated medication list: Include drug names (generic and brand), doses, how often you take them, and what they're for. Carry it with you and share it at every healthcare appointment.
Use one pharmacy: A single pharmacy can track your complete medication history and screen for interactions across all your prescribers.
Question every new prescription: "What is this for? What are the alternatives? Are there risks I should know about given my age or other conditions?"
Don't stop medications without guidance: Many medications in older adults require tapering — abrupt discontinuation can cause withdrawal, rebound, or worsening of the underlying condition.
Review regularly: Ask your prescriber at least once a year to review your full medication list and determine whether anything can be simplified, reduced, or stopped.
Deprescribing: When appropriate, stopping medications that are no longer needed or appropriate is a legitimate and beneficial medical decision — not a failure. Some medications (antidepressants, sedatives, certain blood pressure drugs) can be carefully withdrawn when conditions or goals change.
Key Takeaways
- Aging reduces kidney and liver function, meaning drugs accumulate more in older adults at the same doses — making dose adjustments frequently necessary.
- Polypharmacy (5+ medications) is common in older adults and increases interaction risk, adverse events, and adherence difficulty.
- The Beers Criteria identifies medications that are potentially inappropriate for older adults — including first-generation antihistamines, benzodiazepines, and certain sleep medications.
- Many medication classes increase fall risk in older adults — if falls are a concern, a medication review is essential.
- Some medications cause drug-induced cognitive impairment that can be mistaken for dementia but resolves when the drug is stopped.
- Deprescribing — carefully stopping medications that are no longer appropriate — is a legitimate and often beneficial medical intervention.