BCPS 2013: Geriatrics

Geriatric pharmacy is a field that will continue to grow due to the aging population.  Not only do you need to remember the physical changes that geriatrics experience, but the current guidelines.

Know your guidelines!

PK/PD

Organ System Physiologic Change with Aging Resulting Effect on PK
GI ↑ stomach pH

↓ GI blood flow

Slowed gastric emptying & GI transit

absorption of basic drugs and nutrients

↓ in 1st-pass metabolism

Rate of absorption may be prolonged

Skin Thinning of dermis

Loss of SQ fat

↓/↔ to drug reservoir formation with transdermal formation
Body Composition total body water

↓ lean body mass, ↑body fat

↑ α1-acid glycoprotein

↓/↔ serum albumin

↑ VD and accumulation of lipid soluble drugs (i.e. BZDs)

 

↑ free fraction of highly bound acidic drugs and ↓ free fraction of basic drugs

Liver ↓ liver mass

↓ blood flow to the liver

↔ in phase II drug metabolism

↓/↔ phase I metabolism

↓/↔ CYP450 enzymes

↑ half-life and ↓ CL of drugs with high 1st-pass metabolism

Renal ↓ GFR and renal blood flow

↓ tubular secretion

↓ renal mass

↓ renal elimination of many meds

↑ half-life of renally eliminated drugs and metabolites

Salts of acid drugs: sodium (sodium naproxyn), calcium (atorvastatin calcium), potassium (penicillin G potassium)

Salts of basic drugs: HCl (tetracycline HCl), sulfate (atropine sulfate)

Medications to AVOID in the elderly

  • Beer’s List: includes consensus drugs only
  • Anticholinergic medications (anti-SLUDGE)

 

DEMENTIA

Delirium

Dementia

Depression

SUDDEN, RECENT ONSET

Lasts hrs to weeks

Look for changes in meds, setting, and infection; often reversible

Slow, progressive onset

Irreversible, memory impairment

In the present, with you in the moment (good attention)

Slow or recent onset

Withdrawn and/or sad

Flat affect but emotional

Answers with “I don’t know”

Medication causes of mental status change (reversible):

 

  • Anticholinergics
  • Opioids
  • Glucocorticosteroids
  • BZDs and other sedative/hypnotics
  • Antiparkinsonian med

 

MMSE (mini-mental status exam) Scores:

  • Normal cognitive function= > 24 (out of 30)
  • Mild Alzheimer’s Disease= 21-24
  • Moderate AD= 10-20
  • Severe AD= <10
  • Expected point decline in untreated pt= 2-5 points/year

Also assess a patient’s function (IADLs) and global assessment (CIBIC-Plus)

 

AD Pharmacological Treatment:

1st line: cholinesterase inhibitors (CIs); all equal efficacy; risk of bradycardia and syncope increased for all CIs

  • Donepezil (Aricept): 5mg/d (10mg-23mg/d); also ODT tabs; mild-mod AND severe AD
  • Rivastigmine (Exelon): 1.5-6mg tabs BID [also 9mg (delivers 4.6 mg/d) and 18mg (delivers 9.5 mg/d) patches]; ADRs of  N/V/D more intense than w/ other CIs; mild-mod AD & mild-mod dementia with PD
  • Galantamine (Razadyne): 4-12mg BID or 8-24mg/d (ER formulation); administer with food; syncope at high doses

2nd line/adjunct: glutamatergic therapy (NMDA antagonist; blocks glutamate)

  • Memantine (Namenda): 5mg/d up to 10mg BID; mod-severe AD, may be used in combo w/ Aricept; well tolerated but sometimes confusion seen

**NOTE: CIs and memantine show stat sig improvement in cognition, global assessment, and ADL in high-quality studies but NOT clinically significant!

 

> 50% of pts with dementia have psychosis and agitation

1. Determine cause

2. Non-pharmacological interventions (i.e. educate caregivers, have routine, improve environment)

3. Pharmacologic

A. CIs: ? efficacy; can increase agitation; 1st line for psychosis in Lewy body dementia

B. Atypical Antipsychotics (APs): NO FDA-APPROVED AP for tx of dementia-related psychosis

  • No clear standard on when to use, use for shortest time possible
  • Cochrane review suggests olanzapine and risperidone have most evidence for use in psychosis and aggression; however, use quetiapine if pt has comorbid PD or Lewy body dementia
  • High rate of ADRs: sedation, orthostasis, ↑ risk of stroke/death (OR 1.54 (CI 1.06-2.23), p=0.02)

URINARY INCONTINENCE

Type

Description

Drug-induced causes

Drug Tx

Comments

Urge or Overactive Bladder Loss of mod amts of urine w/ an ↑ in need to void; can result from CNS damage from stroke Cholinergic agents (stimulate bladder; i.e. CIs) Anticholinergic agents (i.e. darifenacin, oxybutynin, solifenacin, tolterodine) -1st line agents

-Oxybutynin has highest CNS effects

Stress incontinence Loss of urine w/ ↑ ab pressure (i.e. sneezing, coughing) α-blockers α-agonists (i.e. PSE and phenylephrine)

Topical estrogens and Duloxetine

-All variable efficacy

-SURGERY normally 1st line

Overflow incontinence Loss of urine b/c of excessive bladder volume caused by outlet obstruction or an acontractile detrusor Anticholinergics, CCB, opioids ↓ detrusor contractions α-blockers (outlet obstruction)

Add-on 5-α reductase inhibitors or bladder antispasmodics (i.e. oxybutynin, tolterodine) à advanced BPH or refractory sxs

Cholinomimetic (bethanechol)

Functional incontinence Inability to reach toilet due to mobility constraints Sedating meds cause confusion; diuretics Remove barriers and obstacles, provide toilet scheduling; assist pt on/off toilet
Mixed incontinence UI w/ >1 cause; usually stress and overactive bladder   Focus on dominating symptoms

Reversible causes of UI: DIAPERS (Delirium, Infection, Atrophic vaginitis and urethritis, Psychiatric disorders, Excessive urine output, Restricted mobility, and Stool impaction)

 

BPH Treatment:

1st line: α-blockers (↓ smooth muscle contraction in urethra); all can cause hypotension!

  • Nonspecific α-blockers: doxazosin (Cardura), prazosin (Minipress, not FDA-approved for BPH), and terazosin (Hytrin)
  • Selective α1-blocker: tamsulosin (Flomax)- less hypotension but ↑rate of ejaculatory dysfunction
  • Selective post-synaptic  α1-blocker: alfuzosin (Uroxatral)

2nd line: α-reductase inhibitors (prevent conversion of testosterone to DHT, DHT stimulates prostate growth)

  • Finasteride (Proscar) and dutasteride (Avodart); decreased libido
  • DO NOT IMMEDIATELY REDUCE SXS! At least 6 mo’s needed for benefit
  • Need baseline PSA to monitor for prostate cancer

Combo therapy for men w/ lower urinary tract symptoms, larger prostate size (>40g) and elevated PSA

  • Dutasteride w/ tamsulosin FDA-approved

Saw palmetto- conflicting efficacy data; may decrease efficacy of reductase inhibitors if used together

Surgery- for severe sxs and those with mod sxs not responding to meds

 

OA

Weight-bearing joints, unilateral, increased with age

Treatment

1st line: APAP up to 4 g/d (< 2.6 g/d if EtOH abuse); 2nd line: opioids, NSAIDs should seldom be used

Other options with ?efficacy: gabapentin (if neuropathic pain), baclofen if muscle spasms, topical agents (i.e. capsaicin, licocaine 5% patch), glucosamine +/- chondroitin

 

RA

Autoimmune disease, common in women (3:1 vs men) and younger people; bilateral inflammation in small joints of hands, wrists, and feet; (+) RF, ESR, C-reactive protein, and normochromic normocytic anemia

Treatment: goal = control inflammation à disease remission

  • 1st line tx: methotrexate (7.5-15mg/week) or potentially other DMARD; 3 months of use before effects seen!
    • For IMMEDIATE tx of pain and inflammation: NSAIDs (analgesic effects w/in hrs, antiinflammation 1-2 weeks) and glucocorticosteroids…both used SHORT-TERM
    • 2nd line if methotrexate does not work: TNF (etanercept, infliximab, adalimumab, etc) or IL inhibitor

 

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