BCPS 2013: Geriatrics
/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Slow or recent onset Withdrawn and/or sad Flat affect but emotional Answers with “I don’t know” |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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