Adverse Drug Reactions 20.11.23

Question 1

Define adverse drug reaction (ADR)?

Answer 1

A response to a medicinal product, or combination of medicinal products, which is noxious and unintended (MHRA 2015)

Question 2

What are 4 wider impacts of ADRs on patients?

Answer 2

Reduced Quality of life

Poor compliance

Reduced confidence in clinicians and the healthcare system

Unnecessary investigations or treatments

Question 3

What are 4 wider impacts of ADRs on the NHS?

Answer 3

Increased hospital admissions

Longer hospital stays

GP appointments

Inefficient use of medication

Question 4

How are ADRs classified (e.g. type ……. Of ADR)?

Answer 4

A - augmented
B - bizarre
C - chronic
D - delayed
E - end of use/withdrawal
F - failure of treatment
G - genetic

Question 5

What’s the most common type of ADR?

Answer 5

Type A ADR (80% of ADRs)

Question 6

Are type A ADRs often life threatening?

Answer 6

Often not life threatening

Question 7

What effect do type A ADRs have

Answer 7

Exaggerated effect of drugs pharmacology at a therapeutic dose

Question 8

Are ADRs does dependent and reversible? If so, how?

Answer 8

Exaggerated effect of drugs pharmacology at a therapeutic dose

Question 9

Example of Type A ADR

Answer 9

AKI with ACE inhibitors

Question 10

Are type B ADRs life threatening?

Answer 10

Yes - can cause serious illness or mortality

Question 11

4 features of type B ADRs

Answer 11

Not related to pharmacology of drug

Not dose related

Can cause serious illness or mortality

Symptoms do not always resolve upon stopping drug

Question 12

1 type C ADR features

Answer 12

ADRs that continue after the drug has been stopped

Question 13

1 type D ADR features

Answer 13

ADRs that become apparent some time after stopping the drug

Question 14

1 type E ADR features

Answer 14

ADR develops after the drug has been stopped

Question 15

3 type F ADR features

Answer 15

Unexpected treatment failure

Could be due to drug-drug interaction or drug-food interaction

Poor compliance with administration instructions

Question 16

1 type G ADR features

Answer 16

Drug causes irreversible damage to genome

Question 17

What is another way (other than ABCDEFG) to classify ADRs?

Answer 17

DoTS

Do - Dose-relatedness
T - Timing
S - Susceptibility

Question 18

Describe the ‘dose-relatedness’ part of DoTS way of classifying ADRs

Answer 18

Hypersusceptibility: ADRs at subtherapeutic doses (eg anaphylaxis with penicillins)

Collateral effects (side effects): ADRs at therapeutic doses (eg hypokalaemia with loop diuretic)

Toxic effects: ADRs at subpratherapeutic doses (eg liver damage with paracetamol)

Question 19

Describe the ‘timing’ part of DoTS way of classifying ADRs

Answer 19

Can be time independent or time dependant.

Time independent: ADRs which can develop during any time during treatment (often due to clinical changes in the patient)

Time dependent:

Rapid - due to rapid administration

First dose - first dose only

Early - Occur early during treatment but resolve as treatment progresses

Intermediate - Occur after some delay

Late - Risk increases with prolonged or repeated exposure

Delayed - occurs some time after exposure or after drug withdrawal

Question 20

Describe the ‘susceptibility’ part of DoTS way of classifying ADRs:

What 4 certain patient groups/populations may have a specific susceptibility to ADRs from a drug?

Answer 20

Age (anticholinergics in elderly patients)

Gender (metoclopramide in females)

Disease states (eg diclofenac in CVD)

Physiological states (eg phenytoin in pregnancy)