Medication in the Elderly PopulationPros, Cons and Side Effects

1
Medication in the Elderly Population-Pros, Cons
and Side Effects

• Saira Girnary
• Pharmacist, Psychiatric Services
• PA Hospital

2
Medication Use in the Elderly

• Elderly patients (gt65 years old) are an ever
  increasing proportion of the population.
• US 1997, this group represented 13 of the
  population.
• Elderly may take on average 6-8 drugs daily

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Problems of Ageing

• The body changes as you get older
• Drug metabolism slows
• -liver function ?
• -renal function ?
• Water/lean body weight/fat content changes
• Changes in drug receptor sensitivity
• Homeostatic changes

4
Polypharmacy

• Multiple pathology
• -cardiac disease, HPT, IHD
• -diabetes
• -asthma/COAD
• -osteoporosis
• -neurological diseases
• -psychiatric illness
• Multiple medications
• Multiple adverse effects
• Interactions
• Additive effects

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Drug Effects on Other Assessments

• Assessments Drug Effects Drug Examples
• Functional Movement disorders Neuroleptics,
  metoclopramide, methyldopa
• (EPSE, TD)
• Balance (neuritis, tinnitus Metronidazole,
  phenytoin, aspirin, neuroleptics
• neuropathies, dizziness antidepressants,
  diuretics, frusemide, levodopa,
• hypotension) benzodiazepines
• Physical Supporting structures Corticosteroids,
  lithium, phenytoin, heparin
• (arthralgias, myopathies,
• osteoporosis)
• Incontinence (urinary Anticholinergic agents,
  TCAs, neuroleptics
• retention, secondary antihistamines,
  benzodiazepines, sedative
• oversedation) hypnotics
• Sexual dysfunction Hypotensive agents, CNS
  depressants, SSRI
• Social Malnutrition Drugs affecting appetite
• Poor dental health Anticholinergic drugs,
  drugs containing glucose

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Drug Effects on Other Assessments

• Assessments Drug Effects Drug Examples
• Psychologic Cognitive impairment ß-blockers,
  corticosteroids, diuretics,
• (metabolic alterations, sulphonylureas,
  propranolol,neuroleptics
• memory loss, dementia) opiates, cimetidine,
  benzodiazepines
• anticonvulsants
• Behavioural toxicity anticholinergics, H2
  antagonists, digoxin
• (insomnia, nightmares bromocriptine, opiates,
  levodopa,
• sedation, agitation sympathomimetics,
  corticosteroids
• delirium, psychosis
• hallucinations
• Depression reserpine, methyldopa, ß-blockers,
  CNS
• depressants, corticosteroids,
  metoclopramide

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Drug Use in Psycho-geriatrics

• Depression
• Schizophrenia
• Paraphrenia
• Bipolar Affective Disorder
• Dementias
• Parkinsons Disease

8
Depression

• Prevalence as high as 10 -15 gt65
• Includes MDD, dysthymia and minor depression
• Up to 20 gt80
• White males gt65 high suicide risk
• gt80 recover if treated
• May be triggered by neuro-degenerative
• changes eg dementia, Parkinsons disease

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Antidepressants

• Tricyclic antidepressants
• amtriptyline, dothiepin,imipramine
• SSRIs (Specific Serotonin Re-uptake Inhibitors),
  fluoxetine, sertraline, citalopram
• SNRI (Serotonin and Noradrenaline Re-uptake
  Inhibitors), venlafaxine
• RIMA (Reversible Inhibitor of Monoamine Oxidase
  A), moclobemide
• NaSSA, mirtazapine
• Mianserin
• Nefazadone

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Side Effects of TCAs

• Anticholinergic -dry mouth
• -blurred vision
• -constipation
• -urinary retention
• -confusion
• Sedative -confusion
• -falls
• Postural hypotension - falls
• - gait
• Weight gain
• Cardiotoxic

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Side Effects of SSRIs

• Improved side effect profile cf TCAs
• Less sedative
• Not cardiotoxic
• Loss of appetite
• Agitation
• Headache
• Diarrhoea
• Confusion
• SIADH ? hyponatraemia (low sodium)
• ? confusion, delirium

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SNRI

• Venlafaxine (Efexor)
• s/e of tricyclics and SSRIs
• Postural drop (hypotension)
• Slightly anticholinergic
• SIADH
• Maybe useful in treatment resistant depression

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NaSSA

• Mirtazapine
• Side effect profile good
• Some sedation at lower doses
• Occasional hypotension
• Weight gain
• Some cases of delirium reported
• Useful where anxiety, sleep disturbances, weight
  loss
• Increasing use amongst elderly

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Depression or Dementia?

• In depression and dementia, there may be a degree
  of cognitive impairment
• Early stages of dementia may mimic depression
  (loss of interest in hobbies, apathy, weight
  loss)
• Depression may lead to a degree of cognitive
  impairment severe enough to be confused with
  dementia (pseudo-dementia).
• If a patient presents with signs and symptoms of
  depression, treat as per normal
• Antidepressants may lead to an improvement in
  cognitive performance

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Antipsychotics (Neuroleptics)

• Used to treat
• Psychotic disorders
• schizophrenia, delusional disorder, psychotic
  symptoms, organic psychosis
• Behavioural disturbances (dementia)
• agitation, aggression
• Sedation -not recommended, but still prevalent in
  nursing homes

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Classes of Antipsychotics

• Typical antipsychotics
• low potency e.g. chlorpromazine (largactil),
  thioridazine (melleril)
• high potency e.g. haloperidol, droperidol
• Atypical antipsychotics
• risperidone (risperdal)
• olanzapine (zyprexa)
• quetiapine (seroquel)
• clozapine (clozaril)

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Side Effects

• Extrapyramidal side effects
• akathisia (restlessness),
• pseudoparkinsonism (masklike face,
• cogwheel, rigidity, resting tremor)
• Orthostatic hypotension-falls
• Anticholinergic side effects-
• constipation, dry mouth, urinary retention,
  cognitive impairment

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Side Effects

• Sedation-falls
• Weight gain (may be useful)
• Sexual dysfunction
• Cardiac Effects
• postural hypotension, tachycardia, cardiac
  arrythmias, prolonged QT
• interval

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Atypical vs. Typical

• Atypical as effective as typical for ve symptoms
• Atypical more effective than typical for -ve
  symptoms
• ? EPSE
• ? ? risk of TD
• ? Atypical have better effect or less detrimental
  effect on cognition

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Risperidone

• Used in late on-set SCZ, chronic SCZ, persistent
  delusional disorder, behavioural problems assoc.
  with dementias
• EPSEs are dose dependent.
• Normal dose in geriatrics is 1-2mg/day
• Maybe useful for psychotic/aggressive behaviour
  in dementias
• Katz et al 1999 compared 3 doses and placebo
• Risk of pseudo-parkinsonism even though
• atypical

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Olanzapine

• ? Less EPSE than risperidone
• Established use in psychosis
• ? use in agitation and aggression
• Somnolence, abnormal gait (dose related)
• Also some anticholinergic activity
• Low start dose (2.5mg) to a maximum of 10mg.
• Like risperidone may exacerbate parkinsonism
  where pre-existing disease.

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Quetiapine

• Relatively new atypical antipsychotic
• Low EPSE, but sedative
• Postural drop
• Dose range 150-800mg per day.
• Advantage is low incidence EPSE
• Drug of first choice in Parkinsons disease
• No evaluation for use in treating aggression in
  dementias

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Atypical Antipsychotics

• Lower risk of EPSE
• BUT
• Some anticholinergic activity (olanzapine)
• EPSE may be dose related (all) and may occur at
  low dose because of age related metabolism and
  receptor sensitivity
• Postural hypotension occurs (all)
• Improvement on typical antipsychotics

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Haloperidol

• High potency antipsychotic
• Used in low doses (0.5-5mg per day)
• Very high risk of EPSE
• Low/no anticholinergic activity
• Sedative
• Treat EPSE with benztropine, orphenadrine,
  benzhexol-highly anticholinergic drugs-may lead
  to confusion etc.

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Chlorpromazine/Thioridazine

• Chlorpromazine (largactil) and Thioridazine
  (melleril)-old style typical antipsychotics.
• Thioridazine use restricted due to cardiac
  problems
• Low potency
• Highly anticholinergic
• Postural drop
• Sedative
• Used almost exclusively in nursing homes
  primarily for sedation.
• Will worsen cognitive function-often prescribed
  on as required basis

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Benzodiazepines

• Sedatives, hypnotics
• Diazepam, Oxazepam, Alprazolam, Nitrazepam,
  Temazepam etc.
• Lipid soluble drugs
• Used to reduce agitation, aid sleep, treat
  anxiety
• Length of time in system greatly extended in age
  as
• Lipid soluble, Liver metabolised
• Leads to confusion, delirium, falls
• Rule of thumb-use short acting drugs with no
  metabolites e.g oxazepam
• Avoid-Nitrazepam, repeated doses of diazepam

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Alzheimers Disease

• Cognitive and functional decline over 5-8 years
  (sometimes longer)
• Short term memory impairment, anxiety,
  depression, motor rigidity, cognitive decline
• Psychotic symptoms
• Cholinergic Hypothesis
• Treatment based on enhancement of cholinergic
  neurotransmission

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Rivastigmine

• Carbamate acetylcholinesterase inhibitor
• Slow the breakdown of acetylcholine
• Inhibits acetylcholinesterase and
  butyrylcholinesterase mainly in the brain
• Increases availability of acetylcholine in the
  brain which may help in Alzheimers Disease
• Selectivity for hippocampus and cortex
• Trade name EXELON
• Available as capsules and liquid
• Improvement in cognitive function, activities of
  daily living etc

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Dosing

• STRICT-start dose 1.5mg bd
• BECAUSE GI SIDE EFFECTS SEVERE
• After 2 weeks if well tolerated dose can be
  increased
• Maximum dose is 12mg per day BUT most patients in
  trials suffered GI side effects at this dose

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Adverse Effects

• Nausea
• Vomiting
• Abdominal pain
• Loss of appetite
• One instance of oesophageal rupture
• C/I in patients with duodenal or gastric ulcers

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Adverse effects

• Somnolence
• Dizziness
• Confusion (!)
• Potential GI bleeding (acetylcholine increases
  acid production in the parietal cells of the
  stomach)

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Donepezil

• Trade name ARICEPT
• Acetylcholinesterase inhibitor
• Indicated for mild to moderate Alzheimers
  Disease
• Available as 5 and 10mg tablets
• Similar adverse effects to rivastigmine although
  probably less GI side effects
• Improvement in cognitive function and in
  activities of daily living

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Rules

• Reduce doses in elderly because
• Reduced ability to metabolise drugs
• Body retains drug for longer (fat soluble)
• Receptors more sensitive-for the same dose of
  drug achieve greater (side) effect
• Avoid anticholinergic drugs where possible
• as lead to confusion and may worsen cognitive
  function in dementias
• Avoid long acting drugs which can accumulate
• Be aware of the number of drugs which can affect
  cognitive function