Prescribing in Elderly

Question 1

What environment do drugs require for absorption?

Answer 1

Acidic drugs require acidic environment

Basic drugs require basic environment

Question 2

Why is drug absorption different in older people?

Answer 2

Increased gastric pH and decreased small bowel surface area

Question 3

What are some issues that may present in older people that may affect absorption?

Answer 3

Previous GI surgery, NJ tube or PEG feed composition, transdermal patches and oedema, proportionally more of basic drugs absorbed

Question 4

How may route of drug delivery need to be changed in an older person?

Answer 4

Liquid/syrup for dysphagia, crush tablets for PEG or NG tube, confused patients may refuse tablets

Question 5

What do drugs bind to in the body?

Answer 5

Albumin binds to acidic drugs and alpha-1 acid glycoprotein binds to basic drugs = older people have low albumin but higher a-1 AG

Question 6

How is drug distribution different in older people?

Answer 6

Increased fat = increases Vd of lipophilic drugs increasing half life
Decreased body water by 10-15% = lower Vd of hydrophilic drugs
Lower Vd and CrCL so half life unchanged

Question 7

How is hepatic drug metabolism different in older people?

Answer 7

Reduced liver function due to decreased size and blood flow = first pass metabolism reduced, biotransforming enzymes reduced

Question 8

How is renal drug metabolism different in older people?

Answer 8

Lower GFR = decreased size, tubular secretion and renal blood flow

Question 9

How are pharmacodynamics different in older people?

Answer 9

Lower doses achieve same effect

Some effects are decreased (e.g B blockers)

Question 10

What drugs should be used with caution in older people?

Answer 10

Those with therapeutic index <2 = theophylline, warfarin, lithium, digoxin, vancomycin, gentamicin

Question 11

What are some drugs that commonly cause side effects?

Answer 11

Warfarin, digoxin, insulin, benzodiazepines, diuretics, NSAIDs, corticosteroids, antihypertensives, opioids, theophylline

Question 12

What are some ways to manage risk of side effects of certain drugs?

Answer 12

Opioids = begin laxative prophylactically
Steroids = osteoporosis prevention if long term
Levothyroxine = remember calcium interferes with absorption

Question 13

What are some side effects of NSAIDs?

Answer 13

GI haemorrhage, decline in GFR, decreased effectiveness of diuretics and antihypertensives

Question 14

What are some side effects of opioids and benzodiazepines?

Answer 14

Impair psychomotor function = falls and confusion

Question 15

What are some side effects of antibiotics?

Answer 15

Resistance and C.diff diarrhoea

Question 16

What are some examples of older people who may be at risk of complications?

Answer 16

Recent hospital discharges and use of multiple drugs
Change in patient condition and multiple prescribers
Impaired cognitive status or communication issues

Question 17

What types of medications are associated with increased risk of complications in older people?

Answer 17

OTC, complementary medicine, drugs with narrow therapeutic index, drugs associated with side effects

Question 18

How common is polypharmacy?

Answer 18

Average use for patient >65 = 4 prescription drugs and 2.5 OTC medications
Average nursing home patient on 7 medications

Question 19

How can polypharmacy be avoided?

Answer 19

Try to avoid treating side effect of drug with another drug and try to prescribe a drug that will treat more than one existing problem

Question 20

What is Beers criteria of medication?

Answer 20

List of >50 medications split into three categories

Question 21

What are the categories in the Beers criteria?

Answer 21

A = always avoided
B = potentially inappropriate 
C = use with caution

Question 22

What is the disadvantage of the Beers criteria?

Answer 22

issues with use in UK as >50% of drugs are not available in Europe

Question 23

What are the components of the STOPP-START tool for prescribing?

Answer 23

STOPP = screening tool for older people's potentially inappropriate prescriptions 
START = screening tool to alert doctors to right treatment

Question 24

What is the purpose of the STOPP-START tool for prescribing?

Answer 24

Highlights prescriptions that are potentially inappropriate if age >=65 and those that should be considered if there are no contraindications

Question 25

What are some GI medications that should be stopped in older people?

Answer 25

Loperamide, prochlorperazine/metoclopramide in Parkinsonism, stimulant laxatives for intestinal obstruction

Question 26

What are some GI medications that should be considered in older people?

Answer 26

PPI for severe GORD or patients >80 on antiplatelets and SSRIs, fibre supplement for chronic symptomatic diverticular disease

Question 27

What are some CV medications that should be stopped in older people?

Answer 27

B-blockers with verapamil, non-selective B-blockers in COPD, CCB in chronic constipation or class 3/4 heart failure, dipyridamole, atorvastatin 80mg for >6 months post MI

Question 28

What are some CV medications that should be considered in older people?

Answer 28

Antihypertensives where SBP >160 mmHg, ACEi in chronic heart failure or post MI, PPI with aspirin and warfarin, warfarin in chronic AF