Chitra Fernando, MD March 18, 2008
Definition Statistics Risk factors Why older adults are more prone to ADE Manifestations Inappropriate medications for older adults What can be done to minimize adverse drug reactions
ADE is an Injury resulting from use of a drug Medication side effects Allergic reactions Medication interactions
ADE - responsible for 5-28% acute geriatric medical admissions. 80% of ADE are due to prescription medications The risk of an adverse reaction increases with every new drug added to the treatment regimen. 140,000 deaths per year due to ADE 95% ADE are predictable and 50% preventable
Age > 85 y Low body wt/bmi > 6 concurrent chronic diagnosis Cr clearance < 50 ml/min > 9 meds > 12 doses/day Prior adverse drug reaction Several prescribing Physicians > 1 Pharmacy
More medical problems More medications/drug interactions Pharmacoeconomic issues Age associated changes in pharmacokinetics and pharmacodynamics
Decreased lean body mass and body water content - Increased concentration of water soluble medications. Eg: Li, Digoxin Increased body fat content fat soluble medications takes longer to clear. Eg: Diazepam, Trazedon Decreased serum albumin increased unbound fraction of med-eg: Phenytoin, Valproic acid, Cefriaxone, Warfarin
Decreased metabolism (decreased liver mass & blood supply) Decreased clearance (decreased no of functioning nephrons and decreased renal blood flow ) Increased sensitivity. Eg: Narcotics, Benzo, Psychotropic, Anticholinergics
Increased falls Confusion Sedation Decreased oral intake Constipation/urinary retention Failure to thrive It is not uncommon for a physician to treat an ADE with another medication.
Inappropriate greater potential to harm than to benefit Beers criteria introduced in 1991 by Beers et al Original criteria was written for elderly persons who were institutionalized and updated in 1997 and 2003 to include all persons over age 65.
Defined medications that should not be prescribed to elderly patients & other medications for which doses, frequencies, durations should not be exceeded.
Beers criteria is widely used as a measure of health care quality and safety Center for Medicare & Medicaid services incorporated Beers criteria into Federal safety regulations for long term care facilities in 1999.
41 medications - Inappropriate under any circumstances 7 medications Inappropriate when used over certain doses, frequencies and durations
Dry mouth, increased thirst, urinary retention, constipation Hypotension, Tachycardia, cardiac arrhythmias, heart blocks
Post op delirium, agitation, hallucination, cognitive impairment, increased risk of falls Pupillary dilatation worsening closed angle glaucoma may threaten vision
TCA Antihistamines-Diphenhydramine (Benadryl) Hydroxyzine (vistaril, Atarax) Antipharkinsonian drugs with atrophine like activity. Oxybutynin, Tolterodine Hyoscyamine Phenothiazine Anticholinergic toxicity occurs more often when two or more anticholinergic drugs are taken together.
High lipid solubility- slower elimination Binds exclusively to plasma proteins-higher plasma drug levels Risk of 2 0,3 0 heart block - pre existing heart disease. Anticholinergic SE - Orthostatic hypotension, falls and fractures
Tertiary amines-amitriptyline, impramine- more anti cho.se Secondary- nortriptyline and desipramine less anti cho. SE Low dose- neuropathic pain SSRI is a better alternative for depression
To manage behaviors associated with dementia-paranoia, agitation, hallucinations & delusions Not usefull in wandering, pacing, repetitive vocalizations
Anticholinergic effects, EP symptoms (bradykinesia, stiffness, cogwheel rigidity, akinesia, akathisia) Lasts longer after d/c. It is not uncommon to treat EP side effects with anticholinergic antiparkinsonian meds results in excessive anticholinergic activity
Atypical antiphychotic medications improved safety profile Clozapine agranulocytosis Olanzapine, Risperidone, Quetiapine Fever extrapyramidal effects and TD
Older-Diazepam, chlordiazepoxide, flurazepam highly lipid soluble Newer-Lorazepam, oxazepam low lipid soluble in low doses only for short term use when indicated
Older (diphenhydramine)- cross BBB Hypnotic, cognitive slowing, delirium, falls more if pre-existing cognitive impairment Second generation antihistamines Fexofenadine, loratadine, cetrizine safer, no notable central effects
10 20% of > 65 yr 15-35% of all peptic ulcer disease due to NSAIDs 20,000 patients die each year
Many present with serious upper GI bleeding 60% individuals with mucosal erosions from NSAIDs were asymptomatic Naproxen, Piroxicam Other SE include Renal impairement, hyperkalemia, HTN, fluid retention, CHF, Indomethacin CNS toxicity Alternatives Acetaminophen, tramadol
2004-2005 ADE requiring ER visits (177504) 3.6% - From Beers criteria 17.3% - Warferin 13% - Insulin 3.2% - Digoxin
ACEI,Potassium sparing diuretics, potassium Benzo, antidepresent, antipsycotic Digoxin, Antiarrhythmics, verapamil Warfarin, NSAIDs, sulfa drugs, macrolides, quinolones, phenyton
When starting meds for chronic medical conditions, start low and go slow Try not to start two medications at the same time
New complaints, worsening of an existing condition R/O SE of medications Discontinue any medication no longer indicated Consider non-pharmacological interventions Avoid drug Interactions - Duplicating side effects
Consider medications with more than one therapeutic effects Brown bag evaluation Maintain accurate records
Educate patient and the care giver about the new medications Simplify the profile Use only one pharmacy Consult pharmacists
Saw palmetto Common use? BPH Adverse Events? Headache, nausea, GI distress, ED
St. John s wort Common uses? Depression, anxiety Adverse Events? Photosensitivity, hypomania
Ginkgo Common uses? Alzheimer s disease, memory, intermittent claudication, macular degeneration Adverse Events? Bleeding, headache, nausea, GI upset, diarrhea, anxiety
Ginseng Common use? Physical & mental performance enhancer Adverse Events? Hypertension, tachycardia
Garlic Common uses? Hypertension, hypercholesterolemia, platelet inhibitor Adverse Events? Bleeding, GI upset, hypoglycemia
Ginger Common uses? Antiemetic, anti-inflammatory, dyspepsia Adverse Events? Bleeding
Kava kava Common uses? Anxiety, sedative Adverse Events? Sedation, hepatotoxicity
Echinacea Common use? Immune stimulant Adverse Events? Hepatotoxicity
Feverfew Common uses? Anti-inflammatory, migraine prophylaxis Adverse Events? Platelet inhibition, bleeding, GI upset
Glucosamine Common uses? Osteoarthritis, rheumatoid arthritis Adverse Events? GI distress, anorexia, insomnia, painful & itchy skin, peripheral edema, tachycardia