Polypharmacy & CAM Flashcards
What is the 4th leading cause of death?
ADRs 4th leading cause of death ahead of pulmonary disease, diabetes, AIDS, pneumonia, accidents, and automobile deaths
Are ADRs preventable?
- Nearly one third of adverse drug events in ambulatory settings are preventable
- Half of adverse drug events in nursing facilities are preventable
What are some common iatrogenic drug problems (drug specific)
Confusion, dry mouth, constipation, blurred vision, urinary retention and orthostatic hypotension with anticholinergics
Confusion and unsteady gait with tricyclics
Digoxin toxicity with normal serum concentrations
CNS toxicity with long-acting benzodiazepines
Confusion with narcotics
Can benzodiazepines make you drowsy?
Yes Indeedy
Older adults (age>50) get 2-3 x as many prescriptions. Typical 85yr old older adult takes 8-9 prescriptions and 2 OTC drugs at once. Why???
More acute & chronic disease
More doctors visits
Drugs often given to counteract a side effect of another drug
Several other factors arising from prescribers, patients and the system
What is the prescribing cascade?
Prescribing cascade-often give drugs to counteract the side effects of another
ADE interpreted as new med condition so given another drug
ADRs look like ‘growing old’. What are some of them?
Unsteadiness
Dizziness
Confusion
Nervousness
Fatigue
Insomnia
Drowsiness
Falls
Depression
Incontinence
Misdiagnosis due to what is a key cause of polypharmacy?
An atypical presentation
Hyperthyroidism:
Young patient=
Tremor
Anxiety
Weight loss
Diarrhoea
Elderly patient=
Depression
Cognitive impairment
Muscle weakness
Atrial fibrillation
Heart failure
Angina
What are some healthcare provider factors that contribute to polypharmacy?
No med review with patient on regular basis
Prescribes without sufficiently investigating clinical situation
Evidence that a particular drug is the “best” drug for a problem
Complicated by the existence of many problems and multiple providers
Provides unclear, complex or incomplete instructions about how to take meds
No effort to simplify medication regimen
Ordering automatic refills
Lack of knowledge of geriatric clinical pharmacology
What CAM modalities have minimal potential for harmful interaction?
- Mind-body therapies
- Sensory therapies
- Body therapies (massage-depending on oils used, chiropractor etc)
- Movement based therapies
What CAM modalities have the potential for interaction with drug treatments?
- Dietary modifications
- Food supplements
- Herbal medicines
- CAM systems
What CAM modalities have no interactions?
- Movement based disciplines
- External ‘energy’
- Mind-body
- Sensory
How to avoid harms with herbal meds?
- Use regulated & tested herbal meds
- Avoid uncontrolled meds
- Consult a qualified herbalist or integrative medical practitioner
- Always take herbal med Hx
- Avoid herbs which cause severe toxicity/use cautiously
- Use certain herbal meds with caution (e.g. anticholinergic side effects)
- Consider and report interactions
Mediterranean diet has similar … to statins
NNT (reduction in CVD events)
In terms of depression and anxiety how does exercise help?
Improves symptoms and halves relapse rate in depression
In anxiety it reduces in patients with chronic physical health problems
What are the effects of exercise on diseases?
Reduced progression from pre-diabetes to diabetes
Symptoms and prognosis of heart and lung disease improved
In mild to moderate to depression what is Hypericum (st johns wort) as effective as?
Antidepressants
What is CAM?
A ‘broad set of health care practices that are not part of that country’s own tradition and are not integrated into the dominant health care system’.
CAM approaches are diverse and include modalities such as herbal and homeopathic therapies, acupuncture, aromatherapy, Reiki, Shiatsu and yoga.
Few CAM approaches are supported by robust efficacy, effectiveness or safety data
Use is wide-spread, with women reportedly the major users both in health and disease
Is Homeopathy available on the NHS?
YES
60% of Scottish GP practices use homeopathic and or herbal preparations.
Concerns about CAM:
Implausibility of most therapies
Evidence of harm
Adverse Effects / Herb-Drug Interactions
Why do people use CAM?
Desire to have personal control over their own health.
Dissatisfied with conventional treatment
Perception that conventional medicine lacks/disregards an holistic approach.
Concerns about the side effects of prescribed medications
All herbals contain … ingredients
ACTIVE
Why does it matter that people in pregnancy use herbals?
No safety or efficacy data
Teratogenesis
Fetogenesis
Drug-Herb Interactions
What is the risk associated with St Johns Wort ?
St Johns wort-potent enzyme inducer-interferes with metabolism and therefore can cause failure of other treatments (such as HIV or immunosuppressants for prevention of organ rejection)
What arrangement was put in place for pharmacovigilance?
Yellow card system
How does age effect absorption of drugs and what may this lead to?
Physiological changes occur that effect the rate but generally not the extent of absorption from the GI tract
May lead to a delay in onset of action
Examples=A reduction in saliva production may result in a reduction in the rate of absorption of buccally administered drugs e.g. glyceryl trinitrate (GTN)
Why as an exception is there an increased absorption of Levodopa in the elderly?
Used for Parkinsons disease. Substantial mucosal metabolism of this drug occurs by the enzyme dopa-decarboxylase, there is a reduced amount of dopa decarboxylase in the elderly- leading to a substantial increase in the absorption of levodopa in the elderly. Elderly patients show a slightly higher peak plasma level and a shorter time to peak than healthy young subjects.
How does distribution of drugs change in the elderly?
Body composition changes
- Reduced muscle mass
- Increased adipose tissue
Fat soluble drugs: ↑ Vd, ↑ T1/2, ↑ duration of
action e.g. diazepam
- Reduced body water
Water soluble drugs: ↓Vd, ↑ serum levels e.g. digoxin
Protein binding changes
Decreased albumin
↓ binding, ↑ serum levels acidic drugs e.g. furosemide
-Increased permeability across the blood-brain barrier
Hepatic metabolism in the elderly is affected by decreased liver mass and decreased liver blood flow. What are the consequences of this?
Toxicity due to reduced metabolism/excretion
Reduced first pass metabolism
↑ in bioavailability with some drugs e.g. propranolol
Can cause ↓ bioavailability of pro-drugs e.g. enalapril
How is excretion of drugs affected by ageing?
Renal function decreases with age
Reduces clearance and increases half-life of many drugs leading to toxicity
Pharmacodynamics: As ageing occurs there is increased sensitivity to particular meds. What is this due to?
Due to:
change in receptor binding,
decrease in receptor number,
altered translation of a receptor initiated cellular response into a biochemical reaction.
Examples: diazepam (↑ sedation), warfarin (↑ anti-coagulation)
More anticoag as the liver is producing fewer clotting factors (therefore higher INR)
What are key principles in prescribing for older people?
Where possible, be clear about the diagnosis to avoid prescribing a drug to manage an adverse effect
Consider whether drug therapy is the best therapeutic action
Lower doses (or reduced frequency of administration) are generally needed
Think about whether the drug causes particular problems in elderly patients
Check whether a lower dose is recommended in the elderly: start at the lowest dose and titrate up slowly (‘start low, go slow’)
Review the new drug and check whether it is achieving its aim
What is good to remember in prescriptions and regimes in elderly?
Review all prescriptions regularly and stop any medicines that are not beneficial
Try to keep regimens as simple as possible
Consider compliance issues which elderly patients in particular may experience
Why is there lack of evidence of drug effects in elderly?
Clinical trials are often performed in a younger population which may mean that benefits do not translate to an older age group
Elderly patients should not be denied proven beneficial medicines on the basis of age
What are some examples of prescribing tools and guides for meds in the elderly?
Beers’ criteria
List of ‘inappropriate’ drugs for older people
Updated occasionally but many weaknesses
START-STOPP criteria (O’Mahony et al)
Advice on medical optimisation
A lot to remember, so mostly research tool
NHS Scotland Polypharmacy Guidance
What is deprescribing?
To reduce, substitute or discontinue a drug
What are some common drugs associated with admission due to ADR?
NSAIDs
Diuretics
Warfarin
ACEI
MOST ADVERSE EVENTS ARE FROM ANTICHOLINERGICS & SEDATIVES
What are some common anticholinergic (antimuscarinic) effects?
Peripheral:
- Dry mouth
- Dry eyes
- Constipation
Central:
- Memory impairment
- Confusion
- Delirium
- Falls
What are some common anticholinergic (antimuscarinic) effects?
Peripheral:
- Dry mouth
- Dry eyes
- Constipation
Central:
- Memory impairment
- Confusion
- Delirium
- Falls
Why should care be taken when treating ‘agitation’ in the elderly?
Sedatives problematic
Increased effects of benzodiazepines
- Falls, confusion
Anti-psychotics
Increased adverse effects
- Postural hypotension, stroke, confusion, movement disorders
Anti-depressants
Less effective, more dangerous?-falls
What adverse effects of NSAIDs are increased?
- Renal impairment
- GI bleeding
NSAIDs-highly protein bound and renally excreted
Because the elderly are more sensitive to the effects of opioids, how does this affect their dosing?
Lower doses needed
Pethidine and tramadol may be less useful
Digoxin: Effects on elderly?
Increased toxicity-lower doses needed
What are the issues with diuretics in the elderly?
Decreased peak effect, but reduced clearance-
Abnormal urea and electrolytes
Other issues around continence and mobility
Often inappropriate indication (swollen legs)
Why do anti-HTs pose a risk in the elderly?
May have exaggerated effects on BP and HR
More likely to be issues with postural hypotension
ACE inhibitors often pro-drugs which may not be metabolised to the active form
Renal adverse effects
How can Warfarin be problematic in the elderly?
Anti-coagulants
- More sensitive to warfarin
- Greater risk from warfarin i.e. GI bleeding, falls
Abx: What increased adverse effects can they cause in the elderly?
Diarrhoea and c. diff infection
Blood dyscrasias (trimethoprim, co-trimoxazole)
Delirium (quinolones)
Seizures
Renal impairment (aminoglycosides)
… Colitis due to C.diff is very common
Pseudomembranous colitis due to C.diff is very common
