Adverse Drug Reactions (ADRs) Flashcards
Define an adverse drug reaction?
Any Noxious or Unintended response to drug occurring at doses used for prophylaxis, diagnosis or treatment
What are the 3 criteria of an adverse drug reactions? (definition)
The response must be:
Noxious
Unintended
Dose for prophylaxis, diagnosis or treatment (i.e. not known unsafe dose)
How many inpatients suffer ADRs?
10-20% of inpatients suffer an ADR
How many hospital deaths are due to ADRs?
0.2-3% of hospital deaths are due to ADRs
(roughly 5-10k deaths/yr)
How many hospital admissions are ADR related?
6.5% of hospital admissions are related to ADRs
What are the 3 time periods of ADRs?
Acute
Sub-Acute
Latent
How quickly does an acute ADR occur?
Within an hour of administration
How quickly does a sub-acute ADR occur?
1-24 hours after administration
How long does a latent ADR take to occur?
2 or more days after administration
What are the 3 levels of ADR?
Mild
Moderate
Severe
Define a mild ADR?
Bothers patient
Dont need to change treatment
Define a moderate ADR?
Patient either needs hospitalisation, changed treatment or additional treatment to solve it.
How bad is a severe ADR?
Disabling or life-threatening
How are ADRs categorised?
Types A-F
What do the types of ADR stand for?
Augmented
Bizarre
Chronic
Delayed
End of Treatment
Failure of Treatment
Why are Type A ADRs called augmented?
Normal response to drug but augmented (exaggerated)
Example of Type A ADRs?
Beta blockers causing bradycardia
Insulin causing hypoglycaemia
Are type A ADRs predictable?
Type A adrs are predictable & related to dosage
What causes a type A ADR?
Excess pharmacological action.
What causes excess pharmacological action in a Type A ADR?
Too high a dose
Pharmaceutical Variation
Pharmacokinetic Variation
Pharmacodynamic Variation
What 4 aspects of a pateint make up their pharmacokinetic variation?
Their drug ADME
Absorption
Distribution
Metabolism
Elimination
What 4 factors affect drug absorption?
Dose
Drugs formulation
GI motility
First pass metabolism
What effects drug metabolism?
altered hepatic function
In what type of drugs is liver disease a particularly important consideration?
Those with a narrow therapeutic range
What effects drug elimination?
Altered renal function, particularly reduced Glomerular Filtration Rate (GFR)
How does pharmacogenetics trigger Type A ADRs?
10% of people are slow metabolisers making them prone to drug toxicity due to their lower first pass metabolism.
What effects pharmacodynamic variation?
- Natural variability between individuals
- Disease states (particularly renal/hepatic disease)
Why are Type B ADRs called bizarrre?
Unpredictable & rare
How serious can type B ADRs be?
Severe, they can kill you
How are some Type B ADRs immunological?
Some Type B ADRs are drug allergies, i.e. examples of type 1 hypersensitivity
What are TYPE C ADRs related to?
Dosage & treatment duration
example of a type C ADR?
Iatrogenic Cushing’s disease
When does a TYPE D ADR occur?
Years after treatment.
Whats unique about a Type D ADR?
Type D ADRs can occur in patients children
What sort of Type D ADRs can immunosuppresive agents cause?
secondary cancers
If a mother is treated with isotretinoin, what ADR can occur?
Child born with craniofacial malformation
What ADR are thalidimide babies an example of?
Type D ADRs
When does a Type E ADR occur
When a treatment is stopped
Alcohol withdrawel is an example of what ADR?
Type E
What are some type E ADRs known as ?
Rebound phenomenom
what type E ADR can occur when beta blockers are stopped?
Beta blockers stopped
Unstable Angina & myocardial infarction can occur
What type E ADR occurs when long term steroid are suddenyl stoppped?
addisonian crisis (low bp low blood sugar high blood K+)
What frequently causes Type F ADRs?
Drug interaction
Is dose related to Type F ADR?
Yes, dose influences type F ADRs
What are the 4 steps for diangosing an ADR?
- Differential Diagnosis
- Medication history
- Asses time of onset & dose relationship
- Lab investigations
What lab investiations are used to diagnose an ADR?
Plasma conc. measurments
Allergy tests
Whats step 1 of diagnosing an ADR?
Differential diagnosis
What is step 2 of ADR diagnosis?
Medication History
Whats step 3 of ADR diagnosis?
Assessing relationship between dose & time of onset
Whats step 4 of ADR diagnosis?
Lab tests
How are ADRs reported?
To the yellow card scheme
What does the yellow card scheme collect info on?
ADRs (side effects)
Defective Meds
Counterfeit meds
Medical device incidents
