Polypharmacy in the elderly

Polypharmacy in the ElderlyPolypharmacy in the Elderly

Marc Evans M. Abat, M.D., FPCP, FPCGM

Internal Medicine-Geriatric Medicine

Head, Center for Healthy Aging, The Medical City

Clinical Associate Professor, Section of Adult Medicine, Department of Medicine, UP-PGH

Marc Evans M. Abat, M.D., FPCP, FPCGM

Internal Medicine-Geriatric Medicine

Head, Center for Healthy Aging, The Medical City

Clinical Associate Professor, Section of Adult Medicine, Department of Medicine, UP-PGH

Objectives

• Definition of polypharmacy

• Prevalence

• Consequences

• Pharmacology and Aging

• Specific Examples

• Interventions

Question: How many drugs must an older person take to make him at risk for polypharmacy???A. 2

B. 5

C. 10

D. A gazillion

• Polypharmacy– The use of more than 5 medications,

some of which may be clinically inappropriate

Prevalence• As much as 25% of the overall population

(Chumney et al., 2006)• For those >65 years old, prevalence

increases to 50%• Prevalence may also be dependent on

comorbidity– More drugs among diabetics than age or sex

matched non-diabetics (Good, 2002)– Other predictors include number of starting

drugs, CAD, diabetes, and use of medications without indications (Veehof et al. 2000)

Question: Any substance may have an interaction with the following EXCEPT:A. Another drug

B. food

C. disease

D. None of the above

Consequences

Adverse Drug Reactions (ADRs) which may include:– Drug-drug interactions

– Drug-disease interactions

– Drug-food interactions

– Drug side effects

– Drug toxicity

• May increase from 7% in those using 2 drugs to 50% in those using 5 and 100% in those using > 10 (Lin 2003; Brazeau 2001)

Quality of Life

• In ambulatory elderly: 35% of experience ADRs and 29% require medical intervention

• In nursing facilities: 2/3 of residents experience ADRs and 1in 7 of these require hospitalization

• Up to 30% of elderly hospital admissions involve ADRs

• Linked to preventable geriatric syndromesFick 2003. Arch Int Med.

Economic

• In 2000: ADRs caused 10,600 deaths

• Annual cost of $85 billion

• $76.6 billion in ambulatory care

• $20 billion in hospitals

• $4 billion in SNF

Fick 2003. Arch Int Med.

Pharmacokinetics and Aging

• characterization and mathematical description of the absorption, distribution, metabolism, and excretion of drugs, their by-products, and other substances of biologic interest as affected by the elderly body

Question: In which of the following situations is drug absorption decreased in the elderly?A. Amoxicillin taken with food

B. Vitamin B12 in patients with atrophic gastritis

C. Calcium carbonate taken with food

D. Ferrous sulfate taken while on omeprazole

Absorption• Age-relatedAge-related gastrointestinal tract and skin

changes seem to be of minor clinical significance for medication usage– Decrease in small intestine surface area– Increase in gastric pH

• Medical conditions (e.g. achlorhydria), other medications or feedings may modify absorption– vitamin B12 in atrophic gastritis– PPIs with sucralfate– Amoxicillin with food

Distribution• Age-related changes

– Decrease in lean body weight– Decrease in total body water(10-15%)– Increased percentage body fat (~15-30%)– Increased fat:water ratio– Decreased plasma proteins, especially albumin

• Occurrence of heart failure, kidney disease with resulting water retention

Question: Drugs that are lipophilic tend to have: A. Shorter half-lives

B. Shorter effects

C. Longer effects

D. None of the above

• Increase in volume of distribution for lipophilic drugs– sedatives that penetrate CNS– Leads to longer half-lives (Linjakumpu 2003)

• Metabolic capacity of phase I reactions decrease

• Phase II reactions are largely unaffected • Greater, active, free concentration in

highly protein-bound drugs

Metabolism• some overall decline in liver metabolic

capacity due to decreased liver mass and hepatic blood flow– Highly variable, no good estimation algorithm– Minimal clinical manifestations

• Concurrent drug use may affect metabolism in both directions

• No formula to estimate this effect

Renal Elimination • Age-related decrease in renal blood flow• GFR decreases by 8 mL/min/1.73

m2/decade • Decreased lean body mass leads to

decreased creatinine production– Serum creatinine not reliable– Need to estimate creatinine clearance and

adjust medications accordingly (i.e. use Cockroft-Gault or MDRD)

Question: In a bedridden, demented, and constipated older patient, which agent may be more appropriate to use A. Fiber bulking agents (e.g. psyllium)

B. bisacodyl

C. lactulose

D. Commercial enema (e.g. Fleet Enema)

Pharmacodynamics and Aging• Effect of the drug on the body with regard

to aging

• Generally, lower drug doses are required to achieve the same effect with advancing age.– Receptor numbers, affinity, or post-receptor

cellular effects may change.– Changes in homeostatic mechanisms can

increase or decrease drug sensitivity.

Inappropriate Medications: Beers Criteria• One of the most, if not the widely used

consensus data for inappropriate medication use in the elderly

• Latest revision in 2003• Covers 2 statements regarding drug use in

elderly:– Those inappropriate for the elderly in general– Those inappropriate for the elderly with regard

to specific conditions

Vitamin and Herbal Use in Older Adults• Highly prevalent among older adults

– 77% in Johnson and Wyandotte county community dwelling elderly

• Generally not reported to the physician

• serious drug interactions possible:– Warfarin, gingko biloba, vitamin E

Non-adherence to Medication Regimens• related to both physician and patient factors

– Large number of medications– Expensive medications – Complex or frequently changing schedule – Adverse reactions– Confusion about brand name/trade name– Difficult-to-open containers– Rectal, vaginal, SQ modes of administration– Limited patient understanding

Geriatric Prescribing Principles• First consider non-drug therapies• Match drugs to specific diagnoses• Try to give medications that will treat more than one

condition• Reduce meds whenever possible• Avoid using a drug to treat side effects of another drug• Review meds regularly (at least q3 months)• Avoid drugs with similar actions/same class• Clearly communicate with patient and caregivers• Consider cost of meds

CARE: Avoiding Polypharmamcy• Caution and Compliance

– Understand side effect profiles– Identify risk factors for an ADR– Consider a risk to benefit ratio– Keep dosing simple- QD or BID– Ask about compliance

CARE: Avoiding Polypharmamcy• Adjust the Dose

– Start low and go slow- titrate– Consider the pharmacokinetics and

pharmacodynamics of the medication

CARE: Avoiding Polypharmamcy• Review Regimen Regularly

– Avoid automatic refills– Look for other sources of medications- OTC– Caution with multiple providers– Don’t use medications to treat side effects of

other meds– Choose drugs to discontinue or substitute

safer medications

CARE: Avoiding Polypharmamcy• Educate

– All medicines, even over-the-counter, have adverse effects-report all products used

– Talk to your patient about potential ADRs– Warn them of potential side effects and report

symptoms– Educate the family and caregiver– Ask pharmacist for help in identifying interactions – Assist your patient in making and updating a

medication list- personal medical record– Avoid seeing multiple physicians– Do not use medications from others

Personal Health Record

• It will reduce polypharmacy and ADRs

• Multiple specialist involved in care

• Transitions in care from independent living, hospitals, nursing homes and assisted living facilities

• Great aid in emergency care

• Provides the patient with more peace of mind…

Personal Health Record Includes:• Patient identifying information

• Doctors contacts

• Caregiver contacts

• Past Medical History and Allergies

• List of all medications, dose, reason they are taking it and whether it is new

NAME PHONE: ( )

PHONE: ( )

MEDICATION NAME

REASON FOR USE

DESCRIBE OR TAPE MEDICINE

HERE

DOCTOR

PHARMACIST

WHEN TO TAKE MEDICINE SPECIAL NOTES

REMEMBER BRING THIS CHART TO ALL DOCTOR APPOINTMENTS

INCLUDE ALL THE MEDICATIONS YOU ARE TAKINGDO NOT CHANGE THE WAY YOU TAKE THE MEDICATIONS WITHOUT CALLING THE DOCTOR

DO NOT SHARE MEDICATIONS

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