Drug use in the elderly

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Drug use in the elderly
2
Assessing Older Adults
Assessment Domain Screening Methods Further Assessment (if screen is positive) See
Medical Medical Medical Medical
Medical illnesses Hx, screening physical examination Additional targeted physical examination, laboratory and imaging tests
Medications Medications review Pharmacy referral Appropriate Prescribing, Medication Assessment
Nutrition Inquire about weight loss (gt10 lbs in past 6 mo), weigh patient Dietary hx, malnutrition evaluation
Dentition Oral examination Dentistry referral
3
Assessing Older Adults
Assessment Domain Screening Methods Further Assessment (if screen is positive) See
Medical Medical Medical Medical
Hearing Handheld audioscope, Brief Hearing Loss Screener, whisper test Ear examination, audiology referral Hearing Impairment, Brief Screener
Vision Inquire about vision changes, Snellen chart testing Eye examination, ophthalmology referral Visual Impairment
Pain Inquire about pain Pain inventory Pain Inventory
Urinary incontinence Inquire if patient has lost urine gt5 times in past year UI evaluation Urinary Incontinence
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Assessing Older Adults
Assessment Domain Screening Methods Further Assessment (if screen is positive) See
Mental Mental Mental Mental
Cognitive status, 3-item recall, Mini-Cog MMSE Mental status examination, dementia evaluation Mini-Cog
Emotional status GDS or other depression screen, inquire Do you ever feel sad or blue? In-depth interview GDS
Spiritual status Spiritual hx In-depth interview, chaplain or spiritual advisor referral
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Assessing Older Adults
Assessment Domain Screening Methods Further Assessment (if screen is positive) See
Physical Physical Physical Physical
Functional status ADLs, IADLs PT/OT referral ADLs, IADLs
Balance and gait Observe patient getting up and walking, orthostatic BP and HR POMA scale POMA
Falls Inquire about falls in past year Falls evaluation Falls evaluation
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Assessing Older Adults
Assessment Domain Screening Methods Screening Methods Further Assessment (if screen is positive) See
Environment Environment Environment Environment Environment
Social, financial status  Social, financial status  Social hx In-depth interview, social work referral
Environmental hazards Environmental hazards Inquire about living situation, home safety checklist Home evaluation
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• Causes of Alteration of
• Drug Response in the Elderly
• Pharmacokinetic
• - Absorption
• - Distribution
• - Metabolism
• - Excretion
• Pharmacodynamic
• Drug interactions

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Oral administration
ELIMINATION
Intravenous administration
INTESTINE
BILE
Drug and
SYSTEMIC CIRCULATION
LIVER
BOUND
FREE
Metabolites
TISSUES
Pharmacokinetic
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Altered Drug Action with Aging

• Pharmacokinetics
• What the body does to the drug
• - Absorption of the drug
• - Distribution of the drug to various organs
  and tissues in the body
• - Metabolism of the drug
• - Renal excretion

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Absorption
Altered Drug Action with Aging

• The gastrointestinal tract undergoes both
  physiologic and anatomic changes with aging
• about 30 decrease in mucosal absorption surface
  in the small bowel and GI motility
• 40 reduction in small intestine blood flow
• galactose, calcium, thiamine, iron

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Altered Drug Action with Aging

• Absorption
• Most frequently does not result in clinically
  relevant changes in drug absorption after oral
  administration
• Factors that can alter drug absorption
• - swallowing difficulties
• - poor nutritional status
• - interaction with other prescription and
• non prescription medications

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Distribution
Altered Drug Action with Aging

• The body composition is altered by aging
• decrease in total body mass
• decrease in total body water
• decrease in lean body mass
• decrease in liver mass
• increase in total body fat

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Distribution
Altered Drug Action with Aging

• Volume of distribution (Vd) of lipophilic drug is
  increased in the elderly
• t 1/2 0.693xVd
• plasma clearance

• Prolong half life (t ½ )

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Altered Drug Action with Aging
Distribution

• Alteration in protein binding of drugs.
• (decrease of albumin).
• acidic drugs and high protein binding drugs eg.
  phenytoin, phenylbutazone, warfarin may increase
  free drug concentration.

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Metabolism The effect of age on hepatic
clearance of drugs
Altered Drug Action with Aging

• Hepatic clearance of drugs is determined by
• 1.Intrinsic ability of the liver to metabolize
  drugs
• phase I reaction by the microsomal mixed
  function oxidase system. Aging decrease phase I
  reaction
• phase II conjugation not affected by
  aging
• 2.Liver blood flow is reduced in the elderly

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Case 1

• ???? 73 ??
• ????? ???????????????? ???????????
• 4 ??????? admitted ??????????? ?????
• ??????? HT 12 ?? ?? minor stroke left
  hemiparesis, good recovery
• Dx Pneumonia
• Rx Antibiotic, hydration, oxygenation

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Case 1

• ????????? ? ?????? ??????????????????? 2
  ???????????????????????????????? ?????????????
  ?????????????????????????????????
  ?????????????????????
• Rx Diazepam 5 mg oral and physical restrain

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Case 1

• In the next morning the patient was well,
  refused any problem last night.
• Next night at 2 AM. She confused and agitated
  again. Diazepam 10 mg given orally and she slept
  for over 24 hr.

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Case 1

• When she woke up, brought to bathroom in wheel
  chair and fell in the bathroom. Bruise over her
  left face.
• Please discuss about her agitation and proper
  management

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MEAN ELIMINATION HALF - LIFE (HOURS)
Drug Young Old Diazepam 24 75
Chlordiazepoxide 10 30 Oxazepam 10 10
Lorazepam 12 12 Alprazolam 10 17
Imipramine 19 24 Amitriptyline 16 22
Desipramine 34 75 Nortriptyline 27 40
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Distribution
Altered Drug Action with Aging

• The body composition is altered by aging
• decrease in total body mass
• decrease in total body water
• decrease in lean body mass
• decrease in liver mass
• increase in total body fat

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Oral administration
ELIMINATION
Intravenous administration
INTESTINE
BILE
Drug and
SYSTEMIC CIRCULATION
LIVER
BOUND
FREE
Metabolites
TISSUES
Pharmacokinetic
23
DRUGS
ORAL ADMINISTRATION
CIRCULATION
BOUND
FREE
ABSORPTION
young
TISSUE
fat
elderly
Vd
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Benzodiazepines

• Depressogenic
• Ataxia --- leading to falls and fractures
• Confusion
• Disinhibition -- aggression sexually
  inappropriate behaviour
• Withdrawal symptoms
• AVOID long acting Benzos such as diazepam and
  flurazepam (except may be in alcohol withdrawal)

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Benzodiazepines

• Short and intermediate acting preferred
• Used as adjunctive therapy mostly (potentiating
  agent)
• Sometimes indicated as a hypnotic after organic
  and other psychiatric disorders have been ruled
  out

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Sedative-Hypnoticand Anxiolytic Drugs in the
Elderly
Drug Activity T1/2 hr Dose Name
Flurazepam Hypnotic 50-100 15 mg hs Dalmadorm
Diazepam Anxiolytic 20-100 2 mg/d or bid Valium
Triazolam Hypnotic 2-3 0.125 mg Halcion
Midazolam Hypnotic 7.5 mg Dormicum
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Sedative-Hypnotic and Anxiolytic Drugs in the
Elderly
Drug Activity T1/2 hr Dose Name
Lorazepam Anxiolytic 10-20 0.5-2 mg/d Ativan
Alprazolam Anxiolytic 12-15 0.25 mg/d- 1.0 mg/d Xanax
Temazepam Hypnotic 5-15 15 mg hs Euhypnos
Oxazepam Anxiolytic 5-20 10 mg X 3/d Serax
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Case 2
???? 75 ?? BW 45 Kg. CC N/V 2 ??? PI case
angina pectoris Rx Propanolol and ASA gr V 9
??????? ?? chest pain ???? Atrial fibrillation
(rate 126/m) Lab Cr 0.9 mg
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Case 2
Rx Digoxin (0.25 mg V x 3 ??? 2 ??. ) HR
94/min ?????? D/C home ?? Digoxin (0.25) 1 tab
OD ??????????? 2 ??? ?????????? ????????
??????? PE P 42/min irregular, BP 90/60
mmHg ???? ? ???? ??????????????????????????
?
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Case 2
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Estimating Renal Function

• Creatinine clearance(Clcr) is used to assess
  renal function, and can be estimated by the
  Cockroft and Gault equation
• Clcr (140-Age)(Wt) S
• (72)(Scr)
• where Clcr is the creatinine clearance in mL/min
• Age is in years
• Wt is the lean or ideal body weight in kg
• Scr is the serum creatinine concentration in
  mg/dL
• S 1.0 for males and 0.85 for females

??. ?????? ?????????
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Estimating Renal Function

• It is important to recognize that due to
  age-dependent declines in renal function, elderly
  patients with normal serum creatinines may have
  Clcr requiring dosage adjustment
• A. 60 kg, 30-year-old man with serum
  creatinine 1 mg/dL
• Clcr (140-30)(60) 1 91.66
  mL/min
• (72)(1)
• B. 60 kg, 70-year-old man with serum
  creatinine 1 mg/dL
• Clcr (140-70)(60) 1 58.33
  mL/min
• (72)(1)

??. ?????? ?????????
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Drug/Special Consideration Dose for Normal Renal Function Adjustment for Renal Failure Adjustment for Renal Failure Adjustment for Renal Failure
Drug/Special Consideration Dose for Normal Renal Function Clcr (ml/min) Clcr (ml/min) Clcr (ml/min)
Drug/Special Consideration Dose for Normal Renal Function gt 50 10 - 50 lt 10
Aminoglycosides Aminoglycosides Aminoglycosides Aminoglycosides Aminoglycosides
Amikacin 7.5 mg/kg q12h 15-20 mg/kg q24h 60-90 q12h or 100 q12-24h 30-70 q12-18h or 100 q24-48h 20-30 q24-48h or 100 q48-72h
Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups.
Gentamicin 1.7 mg/kg q 8 h 4-7 mg/kg q24h 60-90 q8-12h or 100 q12-24h 30-70 q 12 h or 100 q24-48h 20-30 q24-48h or 100 q48-72h
Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups.
Miscellaneous Antibiotics Miscellaneous Antibiotics Miscellaneous Antibiotics Miscellaneous Antibiotics Miscellaneous Antibiotics
Vancomycin 1 g q 12 h or 500 mg q 6 h 1 g q 12 24 h 1 g q 24 - 96 h 1 g q 4 7 days
Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups. Follow serum concentrations and kinetic work ups.
??. ?????? ?????????
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Cardio-vascular drugs

• Digoxin
• High incidence of ADRs
• (digoxin toxicity nausea, vomitting,
  anorexia,
• cardiac arrhythmia, dead)
• Plasma digoxin levels
• Half-life of digoxin increase with aging

??. ?????? ?????????
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Digoxin

• Special consideration
• Subacute toxicity of anorexia with weight loss
  more common initial sign than other GI of
  cardiovascular effects
• Baseline an follow up ECG essential
• Dose on lean body weight and creatinine
  clearance with attention to electrolyte and
  thyroid status

??. ?????? ?????????
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Digoxin

• Adjust dose with Renal impairment and aged
  patients.
• Older adults may develop exaggerated serum/tissue
  concentration due to
• Decreased lean body mass
• Decreased total body water
• Age related reduction in renal function
• Drug Interactions
• Most common K wasting diuretic
• amiodarone

??. ?????? ?????????
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Case 3

• ??? 78 ?? ?????????????? ?????? ???????????????
• 1 ???????
• Case HT 10 ??
• AF 4 ??
• On Atenolol 50 mg OD
• Amlodipine 10 mg OD
• Warfarin 3 mg ?????? ??? ?????
• 1.5 mg ???????????

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Case 3

• FU ???????????? 8 ??? ???????????????
• INR 2.46
• Complaint ??? ?? ??????
• Dx. Pharyngitis
• Rx. Clarithromycin added
• (Hx of penicillin allergy)

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Case 3

• ????????????????????? ????????????? ?????
  ???????????? ?????? ?????????????????
• PE coma,
• pupil dilated left side 4 mm.
• sluggish react to light
• right 3 mm.
• decorticate posture

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Problem

• Coma acute cerebral hemorrhage
• Underlying DM, HT
• Atrial fibrillation with anticoagulant

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Anticoagulants

• Heparin
• Special consideration
• Increase risk of bleeding with age
• Warfarin
• Strongly protein - bound and metabolized by the
  liver
• Dose required for proper anticoagulation is
  lower in elderly

??. ?????? ?????????
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???????????? Drug Interaction ????? Warfarin Significance level 1 (Major severity) ???????????? Drug Interaction ????? Warfarin Significance level 1 (Major severity)
Increase the effect of Warfarin Reduce the effect of Warfarin
Amiodarone Androgens (Danazol, Methyltestosterone, Oxymetholone, Stanozolol) Azole Antifungal Agents (Fluconazole, Itraconazole, Ketoconazole, Miconazole ) Cimetidine Fibric acid (Fenofibrate, Gemfibrozil) Macrolide Antibiotics (Azitromycin, Clarithromycin, Erythromycin) Metronidazole Barbiturates (Phenobarbital)
??. ?????? ?????????
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???????????? Drug Interaction ????? Warfarin Significance level 1 (Major severity) ???????????? Drug Interaction ????? Warfarin Significance level 1 (Major severity)
Increase the effect of Warfarin Reduce the effect of Warfarin
Phenylbutazone Quinine derivatives (Quinine, Quinidine) Salicylates (Aspirin) Sulfonamide (Sulfasalazine, Sulfamethoxazole, Trimethroprim- Sulfamethoxazole) Tetracycline derivatives (Tetracycline, Doxycycline, Oxytetracycline) Thyroid hormones (Levothyroxine) Vitamin E
??. ?????? ?????????
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Drug Interactions

• Significance Rating
• A number 1 through 5 will be assigned to each
  interaction monograph, based on the Editorial
  Groups assessment of the interactions Severity
  and Documentation (defined below)
• is a severe and well documented interaction.
• is an interaction of no more than unlikely or
  possible documentation.
• Major The effects are potentially
  life-threatening or capable of causing permanent
  damage

??. ?????? ?????????
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??. ?????? ?????????
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Key Elements of Patient Education Regarding
Warfarin

• Identification of generic and brand names
• Purpose of therapy
• Expected duration of therapy
• Dosing and administration
• Visual recognition of drug and tablet strength
• What to do if a dose is missed
• Importance of prothrombin time/INR monitoring
• Recognition of signs and symptoms of bleeding
• What to do if bleeding occurs

??. ?????? ?????????
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Ten Most Common Drug-Drug Interactions in the
Elderly
Drug Drug Adverse event
Warfarin sodium (Coumadin) NSAIDs Celecoxib (Celebrex), ibuprofen (Advil, Motrin), naproxen (Aleve, Anaprox, Naprosyn), rofecoxib (Vioxx), sulindac (Clinoril), tolmetin (Tolectin) and others Potentially serious gastrointestinal bleeding due to gastric irritation and erosion of the protective lining of the stomach ability of platelets to form clots
Warfarin sodium Sulfonamides Sulfamethizole (Thiosulfil Forte), sulfamethoxazole (Gantanol), sulfisoxazole (Gantrisin) and others Mechanism unknown probably due to competitive protein binding, and possibly also due to prolongation of warfarin's activity related to decreased production of vitamin K by intestinal flora
Warfarin sodium Macrolides Azithromycin (Zithromax), clarithromycin (Biaxin), erythromycin, troleandomycin (Tao) and others effects of warfarin, bleeding potential, possibly due to decreased production of vitamin K by intestinal flora and inhibited metabolism and clearance of warfarin
Warfarin sodium Quinolones Alatrofloxacin (Trovan), ciprofloxacin (Cipro), gatifloxacin (Tequin), lomefloxacin (Maxaquin), levofloxacin (Levaquin), moxifloxacin (Avelox), norfloxacin (Noroxin), ofloxacin (Floxin), sparfloxacin (Zagam), trovafloxacin (Trovan) and others effects of warfarin, bleeding potential, possibly due to decreased production of vitamin K by intestinal flora and inhibited metabolism and clearance of warfarin
Warfarin sodium Phenytoin Phenytoin (Dilantin) effects of warfarin and/or phenytoin, possibly due to liver metabolism
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Ten Most Common Drug-Drug Interactions in the
Elderly
Drug Drug Adverse event
ACE inhibitors Benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), ramipril (Altace), trandolapril (Mavik) and others Potassium supplements Potassium acetate, potassium acid phosphate, potassium bicarbonate, potassium chloride, potassium citrate, potassium gluconate and others serum potassium ACE inhibition decreases aldosterone production and decreases potassium excretion
ACE Inhibitors Spironolactone (Aldactone) serum potassium unknown, possibly additive effect
Cardiac glycosides Digoxin Antiarrhythmic agents Amiodarone (Cordarone, Pacerone) Digoxin toxicity mechanism unknown, possibly decreased clearance of digoxin
Cardiac glycosides Calcium channel blocking agents Verapamil (Calan, Isoptin, Verelan) Digoxin toxicity due to slowed impulse conduction and muscle contractility, leading to bradycardia and possible heart block
Bronchodilators Aminophylline (Phyllocontin, Truphylline), oxtriphylline (Choledyl), theophylline Quinolones Alatrofloxacin, ciprofloxacin, gatifloxacin, lomefloxacin, levofloxacin, moxifloxacin, norfloxacin, ofloxacin, sparfloxacin, trovafloxacin and others Theophylline toxicity due to inhibition of hepatic metabolism of theophylline by the quinolones
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Case 4

• ??? 72 ??
• high fever and chill 3 hrs PTA
• Underlying DM, HT for 10 years
• Recent history of ischemic stroke with right
  hemiparesis 6 month ago.

50
Case 4

• On the last visit 1 mo ago, the family
• reported frequent crying with desire to
• death because of dependency.
• Nortriptaline 10 mg was added to drug
• regiment. The patient seemed less crying

51
Case 4

• History of frequent urination for 1 wk. and
  drowsy with low grade fever
• PE full urinary bladder up to umbilicus

52
Problem

• Urosepsis
• Acute urinary retention
• Underlying DM, HT and ischemic stroke
• Post stroke depression

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???????? 1 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 1 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
???????? ??????????? ??????????????????????????
Anticholinergics and Antihistamines (Chlorpheniramine, Cyproheptadine, Diphenhydramine, Hydroxyzine, Promethazine) ??????????????????????? ????????????????????? ???????????????????????????????? ????????????????? Anticholinergic ?????????????? ??????????????????? Nonanticholinergic Antihistamine ?????????? Allergic reaction
Antidiabetic Drugs (Chlorpropamide) Chlorpropamide ??????????????? (half-life) ?????????????????????? ??????????????????????????????????????????? ????????????????????????????????????????????????????????????? SIADH ???
??. ?????? ?????????
54
???????? 1 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 1 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
???????? ??????????? ??????????????????????????
Benzodiazepines a. Long-acting Benzodiazepines (Chlorazepate, Clidinium Chlordiazepoxide, Diazepam, Flurazepam) Long-acting benzodiazepines ??????????????????????????????????????????????? ???????????????????? sedation ??????? ?????? ???????????????????? ???????????????????? ??????????????????? ???????? Flurazepam ????????????????????? Benzodiazepine ??????????????? ?????????????
??. ?????? ?????????
55
???????? 1 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 1 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
???????? ??????????? ??????????????????????????
b. Short-acting Benzodiazepines ???????????????? (Alprazolam 2 mg, Lorazepam 3 g, Temazepam 15 mg, Triazolam 0.25mg) ?????? Short-acting Benzodiazepines ???????????????????? ????????????????? ???????????????????????????????? ?????????????????????????????????????? Benzodiazepines ????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????
??. ?????? ?????????
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???????? 1 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 1 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
???????? ??????????? ??????????????????????????
Muscle relaxants ??? Antispasmodics (Carisprodol , Chlorzoxazone, Methocarbomal) ???????????????????????????? Anticholinergic, Sedation, Weakness ????????????????????????????????????????????????
NSAIDs (Indomethacin) Indomethacin - ????????????????????????????????????????????????????????????????
Tricyclic Antidepressants TCA (Amitryptyline, Doxepin) ????????? Orthostatic Hypotension ????????????????????????????? ?????????????? ?????????????????????? Anticholinergic ??? Sedation ???????????
??. ?????? ?????????
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???????? 2 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 2 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 2 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
?????????????????????? ?????????????????????? ???????????
Arrhythmias Tricyclic Antidepressants (Imipramine, Doxepin, Amitryptyline) ???? Proarrhythmic effect ???????? QT interval ???????????
Bladder Outflow Obstruction Anticholinergics and Antihistmines, Antidepressant, Decongestant, Flavoxate, Gastrointestinal, Antispasmodics, Muscle relaxants, Oxybutynin, Tolterodine ??????????????????????? ???????????????? Urinary flow ????
??. ?????? ?????????
58
???????? 2 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 2 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 2 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
?????????????????????? ?????????????????????? ???????????
Depression - Benzodiazepine ?????????????????????????????????? - Sympatholytic agents Methyldopa, Reserpine ????????? ???????????????? ?????????????????
Hypertension Pseudoephedrine, Diet pills ??? Amphetamines ??????????????????????? ?????????????? Sympathomimetics
??. ?????? ?????????
59
???????? 2 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 2 ?????????????????????????????????????????????????????? ????????????????????????????????????????????? ???????? 2 ?????????????????????????????????????????????????????? ?????????????????????????????????????????????
?????????????????????? ?????????????????????? ???????????
Insomnia Amphetamines, Decongestants, MAOIs, Methylphenidate, Theophylline ????????????????????????????????????????????
Syncope or Falls ??????? Benzodiazepine, Tricyclic Antidepressants (Imipramine, Doxepine, Amitriptyline) ???????????? Ataxia ??? Psychomotor Function ????? Syncope ?????????????????????????????
??. ?????? ?????????
60
???????? 3 ???????????????????????????????????????????????? (Functional Ability) ???????? 3 ???????????????????????????????????????????????? (Functional Ability)
?????????????????? ????????????????????
Cognitive Impairment, Delirium, Depression, Dementia ???????????? Anticholinergics, ??????????, Dopamine Agonist (???? Levodopa), ???????????????????(???? Methyldopa)
????? (Falls) ??????? Benzodiazepines (???? Diazepam), ??????????????????? (???? Prazosin), ?????????????? (???? Amitriptyline), ??????????????????? (???? Chlorpromazine)
??????? (Constipation) ????????????Anticholinergics (???? Diphenhydramine), ??????????????? Narcrotic (???? Codeine, Morphine), ????? (Cholestyramine), ??????????????? (???? Iron , Aluminium), Verapamil, Vincristine
??. ?????? ?????????
61
2002 Criteria for potentially inappropriate
medication use in older adults Considering
diagnoses or conditions
Disease or Condition Drug Concern Severity Rating (High or Low)
Hypertension Phenylpropanolamine hydrochloride (removed from the market in 2001), pseudoephedrine diet pills , and amphetamines May produce elevation of blood pressure secondary to sympathomimetic activity. High
Beers Criteria
??. ?????? ?????????
62
2002 Criteria for potentially inappropriate
medication use in older adults Considering
diagnoses or conditions
Disease or Condition Drug Concern Severity Rating (High or Low)
Bladder outflow obstruction Anticholinergics and antihistamines, gastrointestinal antispasmodics, muscle relaxants, oxybutynin (Ditropan), flavoxate, decongestants, and tolterodine (Detrol) May decrease urinary flow, leading to urinary retention High
Beers Criteria
??. ?????? ?????????
63
2002 Criteria for potentially inappropriate
medication use in older adults Considering
diagnoses or conditions
Disease or Condition Drug Concern Severity Rating (High or Low)
Syncope or falls Short-to intermediate-acting benzodiazepine and tricyclic antidepressants (imipramine hydrochloride, doxepin hydrochloride, and amitriptyline hydrochloride) May produce ataxia, impaired psychomotor function, syncope, and additional falls. High
Beers Criteria
??. ?????? ?????????
64
2002 Criteria for potentially inappropriate
medication use in older adults Considering
diagnoses or conditions
Disease or Condition Drug Concern Severity Rating (High or Low)
Chronic constipation Calcium channel blockers, anticholinergics, and tricyclic antidepressant (imipramine hydrochloride, doxepin hydrochloride, and amitriptyline hydrocholoride) May exacerbate constipation Low
Beers Criteria
??. ?????? ?????????
65
HOW TO PRESCRIBE APPROPRIATELY

• Obtain a complete drug history.
• previous treatments and responses
• allergies
• OTC drugs
• nutritional supplements
• alternative medications
• alcohol, tobacco, caffeine, and recreational
  drugs.
• Avoid prescribing before a diagnosis is made.
• Review medications regularly and before
  prescribing a new medication.
• D/C medications ? no longer needed.
• Monitor the use of prn and OTC drugs.

66
HOW TO PRESCRIBE APPROPRIATELY

• Know the actions, adverse effects, and toxicity
  profiles of the medications you prescribe.
  Consider how these might interact or complement
  existing drug therapy.
• Start chronic drug therapy at a low dose and
  titrate dose on the basis of tolerability and
  response.
• Use drug levels when available.
• Attempt to reach a therapeutic dose before
  switching or adding another drug.

67
HOW TO PRESCRIBE APPROPRIATELY

• Educate patient and/or caregiver about each
  medication.
• regimen
• therapeutic goal
• cost
• potential adverse effects
• drug interactions
• written instructions.
• Avoid using one drug to treat the adverse events
  caused by another
• Attempt to use one drug to treat two or more
  conditions.

68
HOW TO PRESCRIBE APPROPRIATELY

• Use combination products cautiously.
• Establish need for more than one drug.
• Titrate individual drugs to therapeutic doses
• switch to combinations if appropriate.
• Communicate with other prescribers.
• Don't assume patients willthey assume you do!
• Avoid using drugs from the same class or with
  similar actions
• eg. alprazolam and zolpidem

69
CRITERIA FOR DRUGS OF CHOICE FOR OLDER ADULTS

• Established efficacy
• Compatible safety and adverse-event profile
• Low risk of drug or nutrient interactions
• Half-life lt24 h with no active metabolites
• Elimination does not change with age or known
  dose adjustments for renal or hepatic function
• Convenient dosing single or twice daily
• Strength and dosage forms match recommended doses
  for older adults
• Affordable to the patient

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WAYS TO REDUCE MEDICATION ERRORS

• Be knowledgeable about the medication's dose,
  adverse events, interactions, and monitoring.
• Write legibly
• to avoid misreading of the drug name (Celexa
  versus Celebrex).
• Write out the directions, strength, route,
  quantity, and number of refills.
• Always precede a decimal expression of lt1 with a
  zero (0)
• never use a zero after a decimal.

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WAYS TO REDUCE MEDICATION ERRORS

• Avoid abbreviations, esp easily confused ones (qd
  and qid).
• Do not use ambiguous directions, eg, as directed
  (ud) or as needed.
• Include the medication's purpose
• in the directions (eg, for high blood pressure).
  
• Write dosages for thyroid replacement therapy in
  µg not mg.
• Always re-read what you've written.

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Age-Associated Changes in Pharmacokinetics and
Pharmacodynamics
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COMPLICATING FACTORS

• Physical Interactions
• Mg, Ca, Fe, Al, or zinc can lower oral
  absorption of levothyroxine and some quinolone
  antibiotics.
• Tube feedings decrease absorption of oral
  phenytoin and levothyroxine.

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COMPLICATING FACTORS

• Decreased Drug Effect
• Warfarin and vitamin K-containing foods (eg,
  green leafy vegetables, broccoli, brussels
  sprouts, greens, cabbage)
• Decreased Oral Intake or Appetite
• alter the taste of food (dysgeusia)
• decrease saliva production (xerostomia)
• making mastication and swallowing difficult.
• dysgeusia include captopril and clarithromycin.
• cause xerostomia include antihistamines,
  antidepressants, antipsychotics, clonidine, and
  diuretics.

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COMPLICATING FACTORS

• Drug-Drug Interactions
• impaired absorption
• eg, sucralfate and ciprofloxacin
• displacement from protein-binding sites
• eg, warfarin and sulfonamides
• inhibition or induction of metabolic enzymes
• two or more drugs have a similar pharmacologic
  effect
• eg, potassium-sparing diuretics, potassium
  supplements, and ACE inhibitors

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COMPLICATING FACTORS

• Drug-Drug Interactions Digoxin
• increase digoxin concentration or effect, or
  both
• amiodarone
• diltiazem
• erythromycin
• esmolol flecainide
• hydroxychloroquine
• Ibuprofen
• indomethacin
• decrease digoxin concentration or effect, or
  both
• aminosalicylic acid
• antacids a
• ntineoplastics
• cholestyramine
• colestipol

• nifedipine
• quinidine
• quinine
• spironolactone
• tetracycline
• tolbutamide
• verapamil

• kaolin
• pectin
• metoclopramide
• psyllium
• sulfasalazine
• St. John's wort

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Enzyme Inhibitors and Inducers

• Selected CYP Isozyme Substrates, Inducers, and
  Inhibitors

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Enzyme Inhibitors and Inducers

• Selected CYP Isozyme Substrates, Inducers, and
  Inhibitors

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Enzyme Inhibitors and Inducers

• Selected CYP Isozyme Substrates, Inducers, and
  Inhibitors

CYP2D6
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Medication Review for the 10-Minute Consultation
The NO TEARS Tool

• Need/indication
• Open questions
• Tests
• Evidence
• Adverse effects
• Risk reduction
• Simplification/switches

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Age-related factors can change drug metabolism

• 4 major age-related pharmacokinetic alterations
• decreased elimination
• decreased hepatic metabolism
• altered distribution in various body compartments
  
• altered absorption

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Age-related factors can change drug metabolism

• Drug absorption
• affected by alterations in gastric pH and
  gastrointestinal motility
• may delay or increase the absorption of drugs.
• Distribution
• affected by the alterations in protein binding
• decreased protein-rich lean body mass or low
  serum albumin levels
• drugs compete for the same protein-binding sites

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Polypharmacy
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Polypharmacy

• The administration of numerous medicines, often
  for multiple indications, at the same time.

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Polypharmacy

• The administration of numerous medicines, often
  for multiple indications, at the same time.
• Derogatory sense
• The probability of adverse drug events increases
  with the number of drugs prescribed

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Polypharmacy

• Six adverse consequences of polypharmacy
• Nonadherence
• (probability increases with complexity of the
  drug regimen)
• Adverse drug reactions
• Drug-drug interactions
• risk of hospitalizations
• Medication errors
• (e.g., taking too much of one drug not enough
  of another)
• costs, from treatment of adverse events

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Adverse Reactions to Common Drugs

• drug-drug interactions drug-nutrient or
  drug-food interactions drug-disease state
  interactions drug-laboratory test interactions

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Adverse Reactions to Common Drugs

• Digoxin Diuretics ß-Adrenergic receptor
  blockers (propranolol) Autonomic Nervous System
  (ANS) Antihypertensive Drugs Anticoagulants
  Theophylline Analgesics Sedative-hypnotic
  agents Tricyclic antidepressants and
  antipsychotic drugs Antiparkinsonian drugs

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Adverse Reactions to Common Drugs

• Digoxin

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Nutrition