Farmakologi Geriatri 2011

Departement pharmacology UNAYA04/07/2023 1

Geriatric Pharmacology And Polypharmacy Problems

MUSTAFA.DS

Associate Magister of PharmacologyUniversity of UNAYA - Aceh

Medical School

Tujuan Pembelajaran

1. Memahami apa saja yang menjadi topik utama dalam farmakoterapi geriatri

2. Memahami bahwa usia berpengaruh pada farmakokinetik dan farmakodinamik dari suatu obat.

3. memahami faktor risiko akan kejadian efek samping obat dan cara untuk mengatasi

4. Memahami prinsip-prinsip peresepan obat untuk pasien geriatri

04/07/2023 2Departement pharmacology UNAYA

04/07/2023 Departement pharmacology UNAYA 3

PENDAHULUAN

sejarah

Gerontologi : geront (Greece) = orang usia lanjut

- Elie Metchnikoff (1903)Geriatri

- Ignatz Nascher (1909)- Dr. Marjorie Warren

(Inggris, 1935)


Definisi

Gerontologi : ilmu yang mempelajari proses menua & semua aspek biologi, sosiologi yang terkait dengan proses penuaan.

Geriatri : cabang ilmu kedokteran yang menitik beratkan pada pencegahan, diagnosis, pengobatan dan pelayanan kesehatan pada usia lanjut.

KARAKTERISTIK PASIEN GERIATRI

1. Usia > 60 tahun2. Multipatologi3. Tampilan klinis

tidak khas4. Polifarmasi 5. Fungsi organ

menurun6. Gangguan status

fungsional 7. Gangguan nutrisi


INTERNAL FACTORSGENETIC

BIOLOGICAL

EXTERNAL FACTORSENVIRONMENT LIFE STYLE

SOCIOCULTURALECONOMIC

NORMAL AGING

Boedhi Darmojo (modified)


SINDROM GERIATRI

Kumpulan gejala dan atau tanda klinis, dari satu atau lebih penyakit, yang sering dijumpai pada pasien geriatri.

- Perlu penatalaksanaan segera

- Identifikasi penyebab

- Comprehensive geriatric assessment


SYNDROME GERIATRY

• Immobility• Instability • Incontinence • Intellectual impairment --- DEMENSIA• Infection --- PNEUMONIA• Impairment of hearing & vision• Isolation (depression)• Inanition (malnutrition)

•Impecunity• Iatrogenic• Insomnia• Immune deficiency• Impotence• Irritable colon


Rapuh rentan terhadap penyakit Mati


Comprehensive Geriatric Assessment

Definition: multidisciplinary management in which the multiple problems of older people are detected, describe, and explained. The resources and strengths of the person are catalouged. The needs for services are assessed. A coordinated care plan is developed with interventions focused on the person’s problems.

1987: Consensus Conference on Geriatric Assessment Methods for clinical decision-making.

D Solomon, et al. J Am Geriatr Soc 1988


Comprehensive Geriatric Assessment

Goals

To improve diagnosis accuracy To guide the selection of

interventions for restoring or preserving health

To recommend an optimal environment for care

To predict outcomes To monitor clinical changes over

time

D Solomon, et al. J Am Geriatr Soc 1988


Geriatric Pharmacotherapy

Prescribed Medications

• Most Commonly Prescribed in Ambulatory older adult:– Cardiovascular– Antiseizure– Non-opioid analgesics– Anticoagulants– Diuretics

• Adverse and drug interactions 7x more likely in geriatric patients. – Self medicating with OTC’s– Incorrect use– Multiple providers– Overdosing when S&S worsen– Using other persons meds– Effects of aging– polypharmacy

• Drug doses should be reduced for elderly clients and gradually increased according to tolerance and adverse reactions.

• Toxicity may develop in the geriatric client with drug doses prescribed for younger adults.


Pharmacokinetics: ADME

• Absorption• Distribution• Metabolism• Excretion

Physiologic changes associated with aging have major effect on

drug therapy• Gastrointestinal:

– ↑ gastric pH– ↓ peristalsis and motility (delayed

emptying times)– ↓ first past effect

• All contribute to slower absorption of oral drugs.

• Cardiac & Circulatory:– ↓ cardiac output– ↓ blood flow

• Impaired circulation can delay transport of drugs to the tissues.


Aging Effects on Distribution: VdAging Effect Vd Effect Examples Body water Vd for hydrophilic

drugsEthanol, lithium

Lean body mass

Vd for 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

Plasma protein (1-acid glycoprotein)

% of unbound or free drug (active)

Quinidine, propranolol, erythromycin, amitriptyline

Aging Effects on Hepatic Metabolism

• Hepatic– ↓ enzyme function– ↓ blood flow

• Drugs are metabolized more slowly and less completely.

• Examples: morphine, meperidine, metoprolol, propranolol, verapamil, amitryptyline, nortriptyline

Aging Effects on Excretion Estimating GFR in the Elderly

• Renal:– ↓ function nephrons– ↓ GFR (glomerular filtration rate)– ↓ blood flow

• Poor excretion of drugs


Aging Effects on Excretion Estimating GFR in the Elderly

• Creatinine clearance (CrCl) is used to estimate glomerular rate

• Serum creatinine alone not accurate in the elderly– lean body mass lower creatinine production– glomerular filtration rate

• Serum creatinine stays in normal range, masking change in creatinine clearance


Estimation of Creatinine Clearance

• Estimate– Cockroft Gault equation

(140-Age) x (IBW in kg)------------------------------ x (0.85 for females) 72 x (Scr in mg/dL)


Measurement of creatinine clearance

– Time consuming– Requires 24 hr urine collection

U Creat (mg/dL) x 24 h Urine Vol (ml)--------------------------------------------- S Creat (mg/dL) X 1440

Polypharmacy

• More common in geriatric clients :– Multiple healthcare providers– Herbal therapy– OTC drugs– Discontinued prescribed drugs

PharmacokineticsAbsorption

• ↓ cardiac output causes 40-50% ↓ gastric blood flow.– Absorption slowed.

• ↓ GI motility (peristalsis)– Delays onset of action

• Reduced gastric emptying– Delays transport of drugs to tissues

Distribution

• Dehydrated elderly clients– ↑ concentration of water soluble drugs

• Increase in body fat – Fat soluble drugs stored, less effect in

circulation

• Decreased serum protein– ↑ free circulating drug

Metabolism

• Decreased hepatic enzyme production, hepatic blood flow, total liver function.

• Decreased liver size with age– Decreases metabolism – ↑Risk of toxicity

• Monitor liver enzyme levels

Elimination

• 35 - 40 % decreased renal blood flow; ↓GFR • -↓elimination = drug toxicity Monitor kidney function

- GFR

• Creatinine clearance indicates true renal function– Consists of 24 hr urine sample, along with serum

creatinine level– Normal adult level=80-130 ml/min

Elimination

• Creatinine level not always a good indicator of renal function in geriatrics d/t ↓muscle mass in elderly clients– Creatinine is a byproduct of muscle metabolism– ↓muscle mass can ↓serum creatinine– Even when renal function is declining, serum

creatinine level can be normal

Drug Groups

• Hypnotics: insomnia common in elderly– Low dose benzodiazepines, with short half lives– Take 1 hr before bedtime

• Restoril (temazepam)• Serax (oxazepam)• Ativan (lorazepam) *recent literature not supportive

• Short term therapy preferred

Drug Groups

• Diuretics / antihypertensives:– Treatment of CHF, HTN– Caution: electrolyte imbalances– Prefer ACE I, ARBs, ca channel blockers

• Altace (ramipril)• Vasotec (enalapril)• Cardizem (diltiazem)• Norvasc (amlodipine)

Drug Groups

• Cardiac Glycosides: increase contractility, slow heart rate; used to treat CHF, AF, atrial tachycardia.– Digoxin

• Monitor closely narrow therapeutic range• Half life doubles on > 80 age group

– Dig toxicity

• Monitor apical rate prior to each dose• Monitor serum dig levels, & cr clearance

Drug Groups

• Anticoagulants: prevent clotting– Caution: risk for falls, bleeding, bruising, frailty,

CVA, orthopedic procedures– Risk of toxicity d/t hypoalbuminemia (warfarin

99% protein bound)– Monitor INR regularly with warfarin (Coumadin)

therapy

Drug Groups

• Antibacterials: decrease dose if client known to have decreased renal function.– Recommended: penicillins, cephalosporins, tetracyclines,

sulfa drugs• Amoxicillin, keflex, cefuroxime, septra, tetracycline

• Aminoglycosides / quinolones: not considered safe over age 75, unless dose reduced

• Gentamycin, tobramycin, Cipro, Avelox, Levofloxacin

Drug Groups

• Gastrointestinal: H2 blockers (histamine)• Cimetidine (Tagamet) not safe any more for

older adults d/t multiple drug interactions• Zantac (ranitidine) preferred

• Laxatives: 75% LTC residents use daily.– Caution: e’lyte imbalances, drug interactions.

Drug Groups

• Antidepressants: dose for geriatric client is 30-50% of young adult dose.– Start low, slowly increase– Tricyclic / bicyclic antidepressants work well

• Elavil (amitriptyline), Prozac (fluoxetine)

– MAO inhibitors avoided except Remeron (mirtazipine)

Drug Groups

• Narcotic analgesic use:– Risk of dose related adverse reaction

• Monitor vital signs closely

Non-Adherence

• Attributing Factors:– Frequency of med– Limitations in vision/hearing– Literacy– Too many meds at different times– Impaired memory– Financial situation– Side effects– Ability to open container– Not understanding purpose

Suggestions to Improve Adherence

• Simplify Process:– Calendar– Pill organizer– Convenient med refills– Easy to open containers– Reduce number of daily doses when possible– Tailor regime to lifestyle

Comprehensive Medication Assessment

• Med names, doses, frequency• Diagnosis associated with each• Beliefs regarding meds• OTC/herbals taken & reason• Side-effects• Financial ability to pay• Ability to obtain• Persons involved in decision making• Use of other drugs/alcohol/caffeine• Drugs obtained from others• Leftovers or recently discontinued

Comprehensive Medication Assessment

• Allergies• Strategies used to remember drug regime• Nutrition/hydration status• Recent drug levels (if appropriate)• Liver/kidney function• Frequency of visits to provider• Level of sensory, memory, and physical ability

Nursing Diagnosis

• Constipation• Risk for injury• Imbalanced nutrition: less than body

requirements• Confusion /acute or chronic• Deficient Knowledge• Noncompliance• Hyper / hypokalemia


“Hit list” of the medications to be avoided in the elderly?

1. Beers Criteria 2. Canadian Criteria

3. START-STOPP Criteria

• Opioid analgesics• NSAIDs• Anticholinergics• Benzodiazepines• Also: CVS, CNS,

musculoskeletal agents

Example of Beers CriteriaDrug Concern SeverityGIT Antispasmodics

Highly anticholinergic and uncertain efficacy & should be avoided for long-term use

High

Anticholinergic & Antihistamine (Phenergan, Avil Benedril, hydroxyzine)

All non-prescription and many prescription antihistamines have potent anticholinergic effects, sedative effetcs, cognitive impairment non-anticholinergic antihistamines are preferred

High

Barbiturates Highly addictive and more side effects than sedative and hypnotics

High



START-STOPP Criteria• START = Screening Tool to Alert doctors to Right Treatment

• STOPP = Screening Tool of Older Person’s potentially inappropriate Prescriptions

• More comprehensive and gives therapeutic alternatives

• May work better than Beers to identify meds that result in negative outcome but there is no evidence that it reduces morbidity, mortality or cost.

Farmakologi Geriatri 2011

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