Adverse drug reactions Flashcards
Which class of drugs has the highest percentage of known side effects?
NSAIDs have highest known side effects
What is an adverse dug reaction?
any response to a drug that is noxious and unintended and that occurs at doses used in man for prophylaxis, diagnosis or therapy
What the EU definition of ADR?
- response to a medicinal product which is noxious and unintended
- ADR from occupational exposure
- ADR from the use outside the terms of the marketing authorisation. including overdose, off-label use, misuse, abuse and med errors
What is an adverse drug event?
an adverse outcome in a patient which occurs after the use of a drug, but which may or may not be linked to use of the drug
What is the definition of a serious reaction?
reaction which results in or prolongs hospitalisation
What did Rawlins Thompson propose in 1977 for reactions?
He proposed 2 types of reaction- A and B
Type A was dose related and relating to pharmacology and Type B as non-dose related
What were Thompson’s Type A drugs factors?
- dose related
- common, predictable
- low mortality
- related to the pharmacology
- bigger the dose, the bigger effect it’ll have
What were Thompson’s Type B drugs factors?
- not dose related
- uncommon
- high mortality
- bizarre reactions
- not related to pharmacology
Explain what is ACE-inhibitor induced angioedema?
- life threatening
- rare
- unlikely to be picked up in clinical trials
- swelling of lips, tongue, airways, lynphx
- can be a side effect of ACE inhibitor long term
Explain what is Type C reaction introduced by Grahame-Smith
- dose related and time related
- uncommon
- related to cumulative dose
- repeated and chronic use of a drug leads to an ADR
- don’t use high dose steiroids- can cause this
Explain what is Type D reaction introduced by Grahame-Smith
- time related
- uncommon
- usually dose related
- occurs soon or some time after the use of the drug
What is an type E ADR?
- withdrawal reactions
- uncommon
- occur soon after withdrawal
- e.g. myocardial infarction after beta-blocker withdrawal and there’s no regulation of receptors
What is an type F ADR?
- common
- dose related
- cause by DDI
Explain what the system DoTS
3 factors- Dose, Time, Susceptibility Dose (response) The ADR can occur - at doses below therapeutic doses - in the therapeutic dose range - at high doses Time ( Course) can be characteristic - with the first dose - early or after a time, or with long-term treatment - on stopping treatment - delayed Susceptibility can be defined - Genetics - Age - Sex - Physiological state - Disease - Exogenous drugs or food
What are the three reactions effects of Dose from DoTS?
- toxic
- collateral
- hypersusceptibility
What does the Dose-response curve look like?
It is therapeutic response on y axis and dose on x axis
an upwards curve that starts with hypersusceptibility and then steadily increases; this is collateral effects. When it plateaus finally this is due to toxic effects
Using dots, how would you treat osteoporosis?
is due to corticosteroids
- traditional approach a Type C reaction
DoTS
Dose- collateral effect
Timing- late
Susceptibility- age, sex
Using dots, how would you treat anaphylaxis?
is due to penicillin
-traditional approach a type B reaction
DoTS
Dose- hypersusceptibility
Timing- first dose
Susceptibility- unclear, but requires previous sensitisation
what are the aims of casuality assessment?
- to decide nature of further enquiries
- to satisfy regulatory requirements
- to decide whether a drug caused an ADR
- to aid signal identification
- to classify reports
- to provide a basis for a label change
Name some factors to consider in casualty assessment?
- temporal relationship
- clinical characteristics of event
- existing info
- patient characteristics
- potential for DDI
- concomitant med
- underlying or concurrent diseases
Describe what a temporal relationship is
- timing can substantially strengthen a causal association as in the case of anaphylaxis
- or the timing of the ADR may be misleading e.g. cholestatic jaundice
What are some clinical events that can occur?
- acute dystonia, blood dyscrasias and skin reactions are usually med-related
What should be looked at in regards to existing info?
- is the ADR in the literature?
- has it been noted by others?
- is it in BNF or SPC?
What should be considered when looking at concomitant medication?
What are other med being taken? What are their adverse effects? Have you taken a full med history? (all drugs being taken) ( some drugs can have same effects)
