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Medication Use and Safety in
the Elderly
Amy N. Thompson, PharmD, BCPS
ACOVE 5
Objectives
• Understand the physiologic changes
associated with aging
• Recognize potentially dangerous
medications for the elderly
• Identify risk factors for adverse drug
events in the elderly
• Identify proper monitoring parameters for
high risk medications in the elderly
Challenges of Prescribing for Older
Adults
• Multiple medical conditions
• Multiple prescribers
• Adherence and cost
• Lack of evidence
• Supplements, herbals and over-thecounter medications
• Different metabolisms and distribution
Physiologic Changes
• Less body water more body fat
• Less muscle mass
• Decreased hepatic metabolism and renal
excretion
• Decreased responsiveness and sensitivity
of the baroreceptor reflex
Distribution
• Decreased body water
– Decreased volume of distribution
• Higher concentration of water soluble agents
• Increased body fat
– Increased volume of distribution
• Increased half-life of fat soluble agents
• Decreased serum proteins
– Increased concentration of agents that are
highly protein bound
Metabolism
• Slowed phase I metabolism
– Oxidation, reduction, dealkylation
• Unchanged phase II metabolism
– Conjugation, acetylation, methylation
Excretion
• Reduced kidney clearance
– 30-40% fall in functioning glomeruli by 80
– 1% (at age 20) ->30% sclerotic glomeruli
• Serum creatinine not accurate predictor of
renal function due to decreased muscle
mass
– Creatinine secretion reduced ~40%
Pharmacodynamics
• Alterations are complex and poorly studied
• Generally the elderly are more sensitive to drug
effects
– Anticholinergics
– Benzodiazepines
• Homeostasis is more effected by drugs
– Postural BP
– EPS
– Cognition
Toxic Response
Therapeutic Window
Therapeutic Response
Age
Medication Use
• People over the age of 65 consume 30%
of all prescriptions in the US and 40% of
all over-the-counter medications
– While they only represent 15% of the US
population
• Clinical trials
– Elderly frequently not included due to
unpredictable drug metabolism and effects
• GF is a 68 y/o AAF
– PMH: Type 2 Diabetes, HTN, GERD, HLP
– Medications: Metformin, glipizide, and
hydrochlorothiazide, simvastatin
• Diagnosed today with AFib
– Started on warfarin 5 mg daily
– Diltiazem 240 mg daily
• One week later:
– GF presents to the ER with bilateral LE edema
– Given a prescription for Lasix 20 mg daily
• What is going on?
Medication Safety
• Think about the medication regimen
before making a new diagnosis
– Consider ADE as etiology of new s/sx
– Consider reducing dose or stopping
medications before treating a ADE with
another medication
Risk Factors for Adverse Drug
Events
• >6 chronic disease states
• >12 doses/day
• >9 Medications
• Low BMI (<22 kg/m2)
• Creatinine clearance <50 mL/min
• Female
Adverse Drug Events
• Linked to preventable problems in the
elderly, such as:
– Depression
– Constipation
– Falls
– Immobility
– Confusion
– Hip fractures
Arch Intern Med.2003;163:271625.
Avoiding Potentially Dangerous
Drugs: Beers Criteria
• Consensus-based list of potentially
inappropriate medications for older adults
• Published 1991; revised in 1997, 2002
• Criteria covered 2 types of statements:
– Medications that should generally be avoided
because they are either ineffective or they
pose a high risk
– Medications that should not be used in older
persons known to have specific medical
conditions Arch Intern Med.2003;163:271625.
Beers Criteria: Anticholinergic
Agents
• Drug classes
– Tricyclic antidepressants
– Antihistamines
– Antispasmodics and muscle relaxants
• Adverse events
– Urinary incontinence
– Constipation
– Confusion, delirium, behavior changes
– Exacerbation of dementia
Beers Criteria: Benzodiazepines
• Avoid entirely if at all possible
• Challenging to stop for patients with long-term
•
•
use
Long-acting
– Prolonged half-life in older adults (days)
– Sedation, cognitive impairment, depression
– Increased risk of falls and fractures
Short-acting
– Increased sensitivity in older adults
– If necessary, use lower doses
Beers Criteria: Pain Medications
• Propoxyphene (Darvon) has limited efficacy and
•
significant side effects
Non-steroidal anti-inflammatory drugs (NSAIDS)
that should be avoided completely:
– Indomethacin has significant CNS side effects
– Ketorolac (Toradol) can cause serious GI and
renal effects
Beers Criteria: Pain medications
• Long-term use of NSAIDS
– Potential for GI bleed
– Renal failure
– Heart failure
– High blood pressure
• Meperidine (Demerol) has low oral
efficacy, active metabolites and CNS
effects
Beers Criteria: Cardiovascular
Agents
• Digoxin
– Should not exceed 0.125 mg/day except when
treating atrial arrhythmias
– Decreased renal clearance, increase in toxic
effects
• Amiodarone
– Associated with QT interval problems
– Lack of efficacy in older adults
Beers Criteria: Disease Specific
• Parkinson’s disease:
•
•
•
•
– metoclopromide and anti-psychotics
Stress incontinence
– alpha-blockers
Hyponatremia
– SSRIs
Constipation
– calcium channel blockers
Cognitive impairment
– Anticholinergics, antispasmodics, and muscle
relaxants
Adverse Drug Events
• National surveillance of ED visits for
outpatient ADE
– 2 year study, 21,000 ADEs reported
• 3,500 required hospitalization
– People >65
• ED visits were twice that of those younger
– 4.9 per 1,000 vs. 2.7 per 1,0000
• Hospitalizations nearly 7 times higher
– 1.6 per 1,000 vs. 0.23 per 1,000
JAMA. 2006;296:1858-1866
Adverse Drug Events
• Drugs for which regular outpatient
monitoring is used to prevent acute
toxicity accounted for 54% of
hospitalizations
• Three medications caused 1/3 of ED visits
– Insulin
– Warfarin
– Digoxin
Adverse Drug Events
• Cardiovascular medications
• Psychotropic medications
• Antibiotics
• Anticoagulants
• NSAIDS
• Anti-seizure medications
NSAID Use and GI Bleeds
• Several risk factors place the elderly population
at increased risk for GI bleeds
–
–
–
–
–
>75 years of age
History of PUD
History of GI bleed
Concomitant use of warfarin
Long term glucocorticoid use
• These patients warrant treatment with
misoprostol or PPI
JAGS.2007; 55:S383–S391.
Medication Safety
• Prescribe one medication at a time
• Start the dose low and titrate up slowly
• Use once daily dosing if possible
– Increases patient adherence
• Monitor the patient for response and
adverse effects
• 3 weeks later….
• GF falls in the middle of the night while
trying to get to the bathroom, she is
subsequently admitted to the hospital
• Upon discharge her medications have
been changed
– D/C lasix, diltiazem
– Start amiodarone 400 mg BID
• Given her current treatment plan would
you recommend any changes?
• Most current medication list
– Warfarin 5 mg daily
– Hydrochlorothiazide 25 mg daily
– Simvastatin 40 mg daily
– Amiodarone 400 mg BID
Medication Safety
• Avoid drug-drug interactions that are
associated with hospitalizations
– ACE Inhibitor plus
• Potassium sparing diuretic or potassium
supplement
– Benzodiazepine
• Antidepressant and antipsychotics
– Warfarin
• New antibiotic, potent CYP inhibitors/inducers
J Am Geriatr Soc.
1996;44(8):944–948
• It has been 1 month since hospital
discharge and GF is returning to clinic for
follow-up
• She complains today of feeling very weak
and have dark stools for the past week
• What is the most likely cause?
Medication Safety
• Educate the patient
– Indication
– Why it is being used
– What they need to watch for
– Provide the patient with an up-to-date
medication list at each visit
• Always assess compliance
Medication Safety
• Always assess the Risk vs. Benefit
– Appropriate medication use requires that benefits of
therapy clearly outweigh the associated risks
– Benefit-to-risk ratio is unique to an individual; the
very medication and dosage that helps one patient
may harm another
• Remember that supplements, herbal and OTC
agents can cause ADE
• Know what your patient is taking
• Its been three months and GF has been
doing well. After her last discharge her
amiodarone was stopped and metoprolol
25 mg BID was started
• Her INR has been stable between 2 and
2.5 since her GI bleed
• She presents to the ER today with signs and
symptoms of a stroke
– INR on presentation 1.4
• Current medications
–
–
–
–
–
Warfarin 5 mg daily
Simvastatin 20 mg daily
Hydrochlorothiazide 25 mg daily
Metoprolol 25 mg BID
St Johns Wort 1 tablet daily
• What is going on?
Medication Safety
• Common herbal agents that can be
hazardous
– Garlic, gingko, green tea
• Increased bleeding time
– St. John’s Wort
• Increased clearance of medications metabolized by
CYP-3A4
– Chromium, gingko, nettle
• Hypoglycemia
Quality Indicators
• All elders should have an up-to-date
medication list in the medical record
• If an elder is prescribed a drug, then the
prescribed drug should have a defined
indication
• If an elder is prescribed a drug, then they
should receive appropriate education
about its use
Quality Indicators
• If an elder receives a new prescription for
a medication known to be high risk,
proper monitoring should be performed
Skills
• Medication reconciliation done at patient
visit and hospitalization
– All prescribed medications
– Topical agents/transdermal patches
– OTC medications
– Herbal products and supplements
– Eye and ear drops
– Inhalers
• Drug list will be printed from Oacis each
Medication Safety
• Is patient taking any over-the-counter
medications or herbal supplements?
– Did you evaluate for harm and drug
interactions?
Skills
• Dose advisor should be used to ensure
proper dosing for any new medication
Skills
• Anytime a new medication is started the
patient will be given a patient education
sheet from Micromedex®
http://www.thomsonhc.com.ezproxy.musc.edu/carenotes/librarian
Skills
• Any new medication prescribed to an elder
will have the indication written in the
directions
– This will aid in patient education and
adherence
Skills
• Any high risk medication will be
appropriately monitored
Medication Safety
• Is the patient currently on amiodarone
therapy?
– Is the patient on warfarin?
• Has the dose been appropriately adjusted?
– Is the patient on digoxin?
• Has the dose been appropriately adjusted?
– Is the patient on simvastatin?
• Is the patient on 20mg/or less a day?
Medication Safety
• If warfarin is prescribed
– PT/INR should be drawn within 4 days for
new starts
– Has a PT/INR been drawn in the past 30
days?
• If not, did you schedule an appointment with the
PharmD today?
Medication Safety
• If a hypoglycemic agent is prescribed
– Has an A1C been checked within the last 6
months?
• If not, have you ordered one to be drawn today?
– Did you ask the patient about s/sx of
hypoglycemia?
• If patient is experiencing s/sx of hypoglycemia,
what did you do to address this issue?
– Reduce the dose of the hypoglycemic agent
– Refer to a CDE for further management
Medication Safety
• Is patient currently receiving NSAID
therapy?
– Did you ask about the signs/symptoms of GI
bleeding?
– Does patient have a history of PUD?
• Are they being treated with a PPI?
– If not, did you start one today?
Medication Safety
• Is patient currently receiving digoxin?
– Did you ask the patient about s/sx of digoxin
toxicity?
• Did patient have s/sx of toxicity?
– If so, did you order a digoxin level today?
Skills
• Each patient will receive an Aging Q3
pillbox to aid in patient adherence
Patient Survey
• Surveyors to randomly select elders after
check-out process occurs:
– Do you know who your doctor is?
– Were you given a medication list today?
– Were you started on a new medicine today?
– If so, were you given an information sheet on
this medication?
– Do you know what this medicine is for?
Take Home Points
• Review and reconcile medications at each
visit:
– Indication for each medication?
– Contraindications? (renal, dementia)
– Can I STOP any medication?
– Is the patient on any OTCs, herbals or
supplements?
• Write indications on prescriptions
– Increase patient knowledge and compliance
Take Home Points
• Avoid high-risk medications if possible
– Beers criteria
– If high-risk medications is used, monitor
appropriately
• When prescribing new medication
– Are there any drug-drug interactions?
– Is it appropriately dosed?
• Remember to look for ADE
Questions???????????