Medication use by older adults is frequent, with 70% of US adults aged 40-79 using at least 1 prescription drug in the last 30 days, and 22.4% using 5 prescription drugs (2).  In this context, there are several principles to improve medication prescribing for older adults.

In initial prescribing:

1. Remember physiologic changes with aging.  Older individuals have physiologic, and sometimes, pathologic changes in how they absorb, metabolize, and excrete medications. 
   1. Gastrointestinal absorption of medications may increase or decrease, partially depending on the gastrointestinal environment they are in.  Decreases in gastric acid production can alter the absorption of medications (e.g., cyanocobalamin, iron). 
   2. Liver and renal function decline, often leading to changes in the amount of active medication present in the body and the rate of metabolism of those medications. 

These changes may require dose adjustment to avoid toxicity.

1. 1.  Body composition changes (e.g., increased adipose tissue, decreased muscle mass, decreased total body water) result in varying medication levels in the body.
   2. Medication target receptor sensitivity may change with aging, requiring either greater or lesser amounts of medication for a comparable effect.
   3. Active medication metabolites (g., codeine metabolizes to morphine; similarly, tramadol metabolizes to a biologically active metabolite) may prolong or potentiate medication effects. 
2. Be aware of pathologic changes of disease.  These include alterations in renal function and medication clearance due to comorbid medical problems or pathologic conditions.
3. Use safe prescribing references. The American Geriatrics’ Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults contains useful, tailored, information.
4. Start low and go slow.  It is common practice to start an elderly patient on 50% of the usual prescribing dose, and to up-titrate slowly, assessing comfort or discomfort with the medication and watching for adverse drug reactions (ADRs).
5. Address high-risk situations (e.g., care transitions, hospital admissions and discharges, care from multiple prescribers).  Use increased caution and care to avoid redundant or duplicative medications or medications which were inadvertently discontinued.
6. Check the cognitive capabilities of the patient.  If a neurocognitive disorder is developing,  enrolling family or caregivers in both the training and dispensing of the patient’s medication regimen is critical.

When prescribing multiple medications:

1. Reconcile medication lists often.  Identify an appropriate indication or intent for each medication, being mindful of non-prescription medications, herbal and holistic therapies, supplements, and over the counter medications, as well as substances such as alcohol, tobacco, cannabis, and other recreational drugs. Availability of a pharmacist can be of help.
2. Don’t assume correct medication adherence.  Reconcile medications with the patient and, when possible, with family or caregivers. When appropriate, check medication levels, using assays measuring active medication levels. Suggest tools and technology to improve adherence and remind patients to take their medications on schedule.  Pill boxes, medication alarms and reminders, or prepackaged blister packs can help improve compliance and track use.
3. Prescribe medications as a team, when possible. 
   1. A pharmacist versed in geriatric medications should review the medication list for indications, interactions, and geriatric dosing.  
   2. A home healthcare nurse or provider can help ensure that the correct medications available for the patient at home (and the wrong medications are removed), and that the patient and family are aware of the correct medication dosing and schedule. 
   3. The patient and family are partners in determining safe ways to ensure the medications are stored and taken.
4. Look for interactions both with prescription and non-prescription meds.  Many medications can potentiate or suppress the effects of other medications, whether through absorption, metabolism or excretion, or at target receptors.  Drug interaction databases can assist in finding which medications may or may not work well together, and include:
   1. Epocrates Interaction Checker (registration required):

https://www.epocrates.com/online/interaction-check.

1. 1. Medscape Interaction Checker

https://reference.medscape.com/drug-interactionchecker

1. 1. WebMD Interaction Checker

https://www.webmd.com/interaction-checker/default.htm

1. 1. Micromedex Drug Interactions (subscription)
2. Avoid prescribing cascades.  Polypharmacy can develop when additional medications are prescribed to treat the side effects and ADRs of other medications. 
3. Deprescribe whenever possible.  Many drug references provide information on safe transitioning or deprescribing of medications.  Avoid, if possible, abrupt stoppage of medications that can precipitate a withdrawal reaction.

Medications and the other 4Ms:

1. Consider the potential impact of medications on other aspects of the 4Ms:
   1. Impact on Mobility and fall risk (e.g. use of anticholinergic medications, antihypertensives, pain medications, sedatives).
   2. Impact on Mentation, cognition (e.g., benzodiazepines, opioids, sedatives, centrally acting medications, muscle relaxants, neuroleptic and psychotropic medications, antiepileptic medications).
   3. Impact on what Matters Most, and the individual’s goals of care. (e.g., if the goal is clarity of thought, will medications compromise that?  If the goal is mobility, will the medications increase fall risk or drowsiness?).
   4. Impact on Multi-Morbidity (e.g., using non-steroidal medications may worsen chronic kidney disease; use of proton pump inhibitors may affect bone strength).