Prescribing

Question 1

inappropriate prescribing?

Answer 1

prescribing drugs which are contraindicated

• prescribing drugs with an inappropriate dose or duration
• prescribing drugs which are likely to adversely affect prognosis
• failure to use a drug which could improve a patients outcome

Question 2

Why is inappropriate prescribing more common in older patients?

Answer 2

1) Older patients have a higher prevalence of chronic disease. 2) Higher levels of polypharmacy (defined as 4 drugs or more) increases the risk of drug-drug and drug-disease interactions 3) Age related changes in physiology, such as altered renal and hepatic function

Question 3

What happens to pharmacodynamics as we age?

Answer 3

Changes as we age lead to altered (increased or decreased) sensitivity to certain classes of drugs. Increased sensitivity: - BDZs - Opioids - Neuroleptics Decreased sensitivity: - Beta blockers - Beta agonists - Furosemide For example, older patients are less sensitive to propranolol because although the drug binds normally to the receptor, changes to the GPCR second messenger system affect the cells response to the drug.

Question 4

pharmacokinetics?

Answer 4

Pharmacokinetics is what the body does to the drug. It includes: - absorption - distribution - metabolism - excretion With ageing, metabolism and excretion of many drugs decrease, requiring dose adjustment of some drugs. This is especially important for drugs, with a narrow therapeutic index.

Question 5

Do changes in drug absorption with age produce any clinically important effects?

Answer 5

No. Age related changes in the GIT are not clinically significant as they do not affect the absorption of most drugs.

Question 6

How is the distribution of drugs affected by age?

Answer 6

total body fat increases, and therefore increases the volume of distribution for fat soluble drugs. Total body water however, decreases. This decreases the apparent volume of distribution of drugs that are water soluble. Serum albumin also decreases and this INCREASES the affects of albumin bound drugs as the level of unbound drug increases as a consequence

Question 7

How does hepatic metabolism change with age?

Answer 7

Reduced liver volume and enzyme activity means that hepatic metabolism of many drugs decreases. To prevent toxic accumulation doses must be reduced, or dosing intervals increased.

Question 8

How is renal elimination affected by age?

Answer 8

Reduction in GFR with age, is important for drugs that are renally excreted. Changes in the GFR decrease the excretion of these drugs. Digoxin is an example of a renally excreted drug with a narrow therapeutic index that often requires a dose reduction as we get older to prevent toxicity.

Question 9

What is the STOPP START criteria?

Answer 9

This consists of criteria for potentially inappropriate drugs called STOPP (Screening Tool of Older Persons Prescriptions) and criteria for potentially indicated drugs called START (Screening Tool to Alert to Right Treatment).

Question 10

Give some examples of drugs affecting the cardiovascular system that should be stopped in the elderly as part of the STOPP START guidance

Answer 10

Loop diuretic as first line monotherapy for hypertension CCBs with chronic constipation Use of aspirin + warfarin without stomach protection Use of diltiazam or verapamil with NYHA Class III or IV heart failure

Question 11

Give some examples of CNS drugs that should be stopped under the STOPP START guidance

Answer 11

TCAs with dementia TCAs with glaucoma TCAs with cardiac conductive abnormalities Long term neuroleptics as long term hypnotics Anticholinergics to treat extrapyramidal side effects of neuroleptic medication

Question 12

Examples of GIT drugs that may need stopping in accordance with the STOPP START criteria

Answer 12

Diphenoxylate, loperamide or codeine phosphate to treat diarrhoea of unknown cause Prochlorperazine or metoclopramide with Parkinsonism PPI for peptic ulcer disease at therapeutic dose for >8 weeks

Question 13

Respiratory drugs that may need reviewing as per STOPP START guidance

Answer 13

Theophylline as monotherapy for COPD Systemic corticosteroids instead of inhaled corticosteroids for maintenance therapy in mild-moderate COPD Nebulised ipratropium with glaucoma

Question 14

What musculoskeletal drugs would you consider stopping in an elderly patient under the STOPP START guidance?

Answer 14

NSAID with a history of peptic ulcer disease or GI bleeding NSAID with moderate-severe hypertension NSAID with heart failure Warfarin and NSAID together

Question 15

Drugs affecting the urogenital system that you may considering stopping in an elderly patient?

Answer 15

Bladder antimuscarinic drugs and dementia Bladder antimuscarinic drugs and glaucoma Alpha blockers in males with frequent incontinence

Question 16

Endocrine drugs that may need reviewing in elderly patients

Answer 16

Glibenclamide or chlorpropamide with type 2 diabetes Beta blockers in those with type 2 diabetes and frequent hypoglycaemic episodes - i.e. > 1 per month Oestrogens without progesterone in patients with intact uterus

Question 17

Name some drugs that are associated with increased falls risk in elderly patients

Answer 17

BZDs (sedative, may cause imbalance) Neuroleptic drugs (may cause gait dyspraxia, Parkinsonism) First generation antihistamines (sedative, may impair sensation)

Question 18

What cardiovascular drugs would you consider starting in an elderly patient?

Answer 18

Warfarin in the presence of chronic AF Aspirin in AF, where warfarin is contraindicated Aspirin or clopidogrel with a documented history of atherosclerosis is patients with sinus rhythm ACEi in chronic heart failure

Question 19

What CNS drugs would you consider initiating in elderly patients according to the START criteria?

Answer 19

L-DOPA in idiopathic Parkinson’s disease with definite functional impairment and disability Antidepressant in moderate to severe depressive symptoms lasting at least 3 months

Question 20

What gastrointestinal drugs should be started in elderly patients as per the START criteria?

Answer 20

Proton pump inhibitor with severe gastro-oesophageal reflux disease or peptic stricture requiring dilatation. Fibre supplement for chronic, symptomatic diverticular disease with constipation.

Question 21

Respiratory medications that should be started as per the START criteria

Answer 21

Regular inhaled beta 2 agonist or anticholinergic agent for mild to moderate COPD. Regular inhaled corticosteroid for moderate-severe asthma of COPD, where predicted FEV1 is <50%. Home oxygen with documented chronic type 1 respiratory failure (pO2 <8kPa) or type 2 respiratory failure.

Question 22

What musculoskeletal medication should be given to elderly patients as part of the START criteria?

Answer 22

DMARDs with active moderate-severe rheumatoid disease lasting >12 weeks. Bisphosphonates in patients taking maintenance oral corticosteroid therapy. Calcium and vitamin D supplementation in patients with osteoporosis (radiological evidence or previous fragility fracture).

Question 23

What anti-emetic is a good alternative to metoclopramide in patients with Parkinson’s disease?

Answer 23

Ondansetron, which is a 5-HT3 receptor antagonist, would be the preferred option.

Question 24

dementia?

Answer 24

Dementia is a term for a syndrome characterised by acquired global impairment of higher mental functions WITHOUT impairment of consciousness. The key mental functions that are impaired are: - Cognition: memory impairment, speech and language problems, difficult carrying out complex actions (apraxia) such as dressing or somatosensory integration (e.g. differentiating between a toilet and wastebin) - Neuropsychiatric features: character or behavioural changes - ADLs Diagnosis always requires a history of acquired progressive impairment.

Question 25

What are the core features of depression?

Answer 25

Low energy Low mood Reduced enjoyment (anhedonia) Somatic (biological) symptoms may also be present: - diurnal variation in mood - reduced/ increased appetite - waking early/ hypersomnia

Question 26

How common is depression in the elderly population?

Answer 26

Depression is the most common mood disorder in the elderly. Significant depression (sometimes with strong suicidal ideation, and delusions of guilt or hopelessness) is found in: - 10-15% of community patients - 20% of older hospital patients - 30-40% of care home residents

Question 27

What are the pathological features of Alzheimer’s disease (AD)?

Answer 27

AD is the most common cause of dementia, accounting for at least half of cases. Neurotoxicity is caused by extracellular beta amyloid plaques and intracellular neurofibrillary tangles caused by tau protein. Neuroimaging reveals to space occupying lesions and may show generalised cortical atrophy and (highly suggestive) thinning of the temporal lobe and hippocampi.

Question 28

What are the important clinical features of Alzheimer’s disease?

Answer 28

diffuse deficits in short term memory, impairment of language, and as the condition progresses, impairment of judgement, visuospatial ability and in sustaining attention. Onset of the condition is typically insidious and delays to diagnosis are therefore common. Prognosis is between 5-10 years from diagnosis. On average, a family history doubles the risk of someone developing AD over their lifetime.

Question 29

Which patients are most at risk of AD?

Answer 29

here is no reliable biomarker for predicting which patients are likely to develop AD. At risk groups include those with mild cognitive impairment, which refers to patients with a cognitive deficit (usually amnesic type) significantly greater than the expected given age and education but no clear evidence of dementia and preserved function. Patients with MCI have a 10-15% risk of developing AD (although many remain stable and revert to normal cognitive ageing). Because AD is so common, even atypical presentations such as those below the age of 65 are likely to be due to AD. NEVER exclude it from your differential