• Medications play crucial role in geriatric health care as they treat chronic diseases, alleviate pain and improve quality of life
• Age-related changes in drug disposition and pharmacodynamic responses have significant clinical implications
• Increased use of a number of medications in elderly raises the risk of medicine-related problems that may occur
• Medication use and the incidence of adverse drug outcomes increase with advancing age
• It is important to ensure quality use of medicines in older people
• Large number of new drugs available each year
• Off-label indications are expanding• Advanced understanding of drug-drug interactions
• Increasing popularity of “nutriceuticals”
• Multiple co-morbid states
• Polypharmacy
• Medication compliance
• Effects of aging physiology on drug therapy
• Medication cost
• Rate of absorption may be delayed
• Lower peak concentration• Delayed time to peak concentration
• Factors:
• Increased GI pH
• Decreased gastric emptying
• Dysphagia
• Route of administration
• Co-morbidity conditions
• Aging Effect
• Vd Effect• Examples
• body water
• Vd for hydrophilic drugs
• ethanol, lithium
• lean body mass
• Vd for drugs that
• bind to muscle
• digoxin
• fat stores
• Vd for lipophilic drugs
• diazepam, trazodone
• plasma protein (albumin)
• % of unbound or free drug (active)
• diazepam, valproic acid, phenytoin, warfarin
• Reduced amount of water in the body - fat soluble drugs remain longer in the body with prolonged effects – of importance for some sedatives and anxiolytics
• Reduced liver function
• Pathway• Effect
• Examples
• Hepatic microsomal
• Phase I: oxidation, hydroxylation, dealkylation, reduction
• Conversion to metabolites of lesser, equal, or greater• diazepam, quinidine, piroxicam, theophylline
• drug metabolizing activity
• may be reduced due to:
• decreased hepatic• blood flow
• decreased liver size
• and mass
• Phase II: glucuronidation, conjugation, or acetylation• Conversion to inactive metabolites
• lorazepam, oxazepam, temazepam
• Examples: morphine,
• metoprolol, propranolol,
• verapamil, amitryptyline,• nortriptyline (sensitivity to
• beta-blockers reduced)
• Reduced kidney function - decreased excretion of some cardiovascular drugs, some antibiotics, diabetic drugs, antiinflammatory drugs – need to reduce dosage
• Decreased kidney size
• Decreased renal blood flow
• Decreased number of functional nephrons
• Decreased tubular secretion
• Result: glomerular filtration rate (GFR)
• Decreased drug clearance: atenolol, gabapentin, H2 blockers, digoxin, allopurinol, quinolones
• Creatinine clearance (CrCl) is used to estimate glomerular rate
• Brain and nervous system more sensitive to psychotropic and analgesic drugs – dizziness, confusion, cognitive impairment
• Decreased capacity to regulate blood pressure – blood pressure fall, fainting, vertigo when using drugs for hypertension
• Gastrointestinal sensitivity to anti- inflammatory drugs - bleeding
• Balance between overprescribing and underprescribing
• Correct drug
• Correct dose
• Targets appropriate condition
• Is appropriate for the individual patient
• Avoid “a pill for every ill”
• Always consider non-pharmacologic therapy
• Adverse drug events (ADEs)
• Drug interactions• Duplication of drug therapy
• Decreased quality of life
• Unnecessary cost
• Medication non-adherence
• Responsible for 5-28% of acute geriatric hospital
• admissions• Greater than 95% of ADEs in the elderly are
• considered predictable (Type A) and approximately
• 50% are considered preventable
• Most errors occur at the ordering and monitoring
• stages
• Most common medications associated with ADEs in elderly
• Opioid analgesics
• NSAIDs
• Anticholinergics
• Benzodiazepines
• Also: cardiovascular agents, CNS agents, and musculoskeletal agents
• High potential to cause severe ADEs in elderly – amitriptyline, chlorpropamide, digoxin >0.125mg/d, disopyramide, antispasmodics, meperidine, methyldopa, pentazocine, ticlopidine
• High potential but less severe: antihistamines, diphenhydramine, dipyridamole, ergot mesyloids, indomethacin, muscle relaxants
• ADE interpreted as new medical condition
• Drug 1• Drug 2
• ADE interpreted as new medical condition• Drug 3
• Rochon PA, Gurwitz JH. Optimizing drug treatment in elderly people: the prescribing cascase. BMJ 1997;315:1097.
• Combination
• Risk• ACE inhibitor + potassium
• Hyperkalemia
• ACE inhibitor + K sparing diuretic
• Hyperkalemia, hypotension
• Digoxin + antiarrhythmic
• Bradycardia, arrhythmia
• Digoxin + diuretic Antiarrhythmic + diuretic
• Electrolyte imbalance; arrhythmia
• Diuretic + diuretic
• Electrolyte imbalance; dehydration
• Benzodiazepine + antidepressant Benzodiazepine + antipsychotic
• Sedation; confusion; falls
• CCB/nitrate/vasodilator/diuretic
• Hypotension
• Doucet J, Chassagne P, Trivalle C, et al. Drug-drug interactions related to hospital admissions in older adults: a prospective study of 1000 patients. J Am Geriatr Soc 1996;44(9):944-948.
• Combination
• Risk
• NSAIDs + CHF
• Thiazolidinediones + CHF
• Fluid retention; CHF exacerbation
• BPH + anticholinergics
• Urinary retention
• CCB + constipation Narcotics + constipation
• Anticholinergics + constipation
• Exacerbation of constipation
• Metformin + CHF
• Hypoxia; increased risk of lactic acidosis
• NSAIDs + gastropathy
• Increased ulcer and bleeding risk
• NSAIDs + HTN
• Fluid retention; decreased effectiveness of diuretics
• 1.
• 2.
• 3.
• 4.
• 5.
• 6.
• 7.
• 8.
• 9.
• When meeting the patient - get ready to spent more time and understand the patient and his problems – see the whole patient as a part of whole
• Identify the patient`s need of treatment – diagnosis important - Have a
• comprehensive view
• Symptoms can be adverse reactions to drugs Record which other drugs the patient is using
• Evaluate what has to be prescribed – make a benefit risk assessment, is there any medication which should be stopped – must avoid Polypharmacy
• Which dosage and administration form is appropriate
• Make a plan for the treatment, when to meet for a follow-up of the effects of the treatment and discuss this with the patient or her or his carer
• Use of lower doses, longer intervals, slower titration are helpful in decreasing the risk of drug intolerance and toxicity
• Careful monitoring is necessary to ensure successful outcomes
• Remember:
• Balance between under prescribing and overprescribing
• Avoid “a pill for every ill”
• Always consider non-pharmacologic therapy
• 10. Report adverse reactions if they occur
• Always take utmost care and responsibility while prescribing medicines to an aged patient – think, re-think, discuss with colleague/seniors - if needed and apply your best intellectual knowledge - Be cautious with NSAIDS, CNS drugs, CVS drugs, diuretics and oral hypoglycaemics