Prescribing in the Elderly

Question 1

What are some common side effects of anticholinergics?

Answer 1

Confusion, dry mouth, constipation, blurred vision, urinary retention and orthostatic hypotension

Question 2

What are some common side effects with tricyclic antidepressants

Answer 2

Confusion and unsteady gates

Question 3

What are some side effects of digoxin?

Answer 3

Toxicity at what would typical be normal concentrations

Question 4

What are som side effects of long acting benzodiazpines?

Answer 4

CNS toxicity

Question 5

What are some common side effects with narcotics?

Answer 5

Confusion

Question 6

What is meant by a prescribing cascade in the elderly?

Answer 6

Drug 1—–> adverse side effect
Drug 2—-> prescribed to treat ADR—-> New ADR
Drug 3—> prescribed to treat ADR……..

Question 7

According to studies what are the most common conditions that cause D2D interactions

Answer 7

Type 2 diabetes
Depression
Heart failure

Question 8

What contributes to polypharmacy?

Answer 8

No reviews with patients on a regular basis
Presumes the patient expects medications
Prescribes without sufficient investigation
Provides unclear instructions of how to use medication

Question 9

What drugs cause the most admissions to hospital

Answer 9

NSAIDS
Diuretics
Warfarin

(anticholinergics and sedatives not ideal)

Question 10

What are some common antimuscarinic drugs

Answer 10

Gastrointestinal antispasmotics
Drugs for overactive bladder
Tricyclic antidepressants
Sedating antihstamines
Antiemetics
Antipsyhcotics
Ranitidine
Phenytoin
Citalopram
Fluoxetine
Lithium
Digoxin
Temazepan

Question 11

How does the absorption of drugs change in older people

Answer 11

Effect the rate of absorption, this may lead to a delay of onset

e.g. less saliva in mouht= less uptake for GTN

Question 12

How does the distribution of drugs change in an elderly person?

Answer 12

Reduced muscle mass
Increased adipose tissue (Increased duration of action)
Reduced body water (increased serum levels)
Protein binding changes (decreased albumin, decreased serum levels)
Increased permeability across the blood brain barrier

Question 13

How is the metabolism of drugs altered in elderly people

Answer 13

Hepatic metabolism is altered due to decreased liver mass and decreased liver blood flow

This leads to an increase in toxicity due to a decrease of metabolism and excretion

Question 14

How does the excretion of drugs change with age?

Answer 14

Renal function decreases with age

Question 15

How are pharmacodynamics different in elderly people?

Answer 15

Change in receptor binding
Decreased number of receptors
Altered translation of a receptor initiated cellular response

Question 16

What are the principles of prescribing for old people?

Answer 16

Where possible be clear about the diagnosis to avoid prescribing due to an ADR

Consider whether drug therapy is the best therapeutic action

Lower doses are generally needed (start small and work up)

Think about what drug does

Review drugs

Question 17

What problems can you run into when prescribing psychiatric drugs?

Answer 17

Sedative problems (falls, confusion)

Anti-psychotics (postural hypotension, stroke, confusion, movement disorders)

Anti-depressants- less effective, more dangerous

Question 18

What problems can you run into when prescribing analgesic drugs?

Answer 18

More sensitive to effects, lower doses needed
Pethidine and tramadol may be less useful

NSAIDs- increased adverse effects e.g. renal imparement, GI bleeding

Question 19

What problems can you run into when prescribing cardiovascular drugs?

Answer 19

Digoxin- increased toxicity, lower doses required

Diuretics- decreased peak effect, reduced clearance, abnormal U&E’s
Other issues around continence and mobility

Question 20

What problems can you run into when prescribing antihypertensive drugs?

Answer 20

May have exaggerated effect son 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

Question 21

What problems can you run into when prescribing antibiotics?

Answer 21

Diarrhoea and c.diff
Blood dyscrasias (altered mixture of blood cells)
Delirium (quinolones)
Seizures
Renal impairment