Adverse Drug Reactions 20.11.23 Flashcards
Define adverse drug reaction (ADR)?
A response to a medicinal product, or combination of medicinal products, which is noxious and unintended (MHRA 2015)
What are 4 wider impacts of ADRs on patients?
Reduced Quality of life
Poor compliance
Reduced confidence in clinicians and the healthcare system
Unnecessary investigations or treatments
What are 4 wider impacts of ADRs on the NHS?
Increased hospital admissions
Longer hospital stays
GP appointments
Inefficient use of medication
How are ADRs classified (e.g. type ……. Of ADR)?
A - augmented
B - bizarre
C - chronic
D - delayed
E - end of use/withdrawal
F - failure of treatment
G - genetic
What’s the most common type of ADR?
Type A ADR (80% of ADRs)
Are type A ADRs often life threatening?
Often not life threatening
What effect do type A ADRs have
Exaggerated effect of drugs pharmacology at a therapeutic dose
Are ADRs does dependent and reversible? If so, how?
Exaggerated effect of drugs pharmacology at a therapeutic dose
Example of Type A ADR
AKI with ACE inhibitors
Are type B ADRs life threatening?
Yes - can cause serious illness or mortality
4 features of type B ADRs
Not related to pharmacology of drug
Not dose related
Can cause serious illness or mortality
Symptoms do not always resolve upon stopping drug
1 type C ADR features
ADRs that continue after the drug has been stopped
1 type D ADR features
ADRs that become apparent some time after stopping the drug
1 type E ADR features
ADR develops after the drug has been stopped
3 type F ADR features
Unexpected treatment failure
Could be due to drug-drug interaction or drug-food interaction
Poor compliance with administration instructions
1 type G ADR features
Drug causes irreversible damage to genome
What is another way (other than ABCDEFG) to classify ADRs?
DoTS
Do - Dose-relatedness
T - Timing
S - Susceptibility
Describe the ‘dose-relatedness’ part of DoTS way of classifying ADRs
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)
Describe the ‘timing’ part of DoTS way of classifying ADRs
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
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?
Age (anticholinergics in elderly patients)
Gender (metoclopramide in females)
Disease states (eg diclofenac in CVD)
Physiological states (eg phenytoin in pregnancy)
