6. Pharmacovigilance Flashcards
Define pharmacovigilance.
Identification, assessment and subsequent prevention of adverse drug reactions whilst optimising benefits
What did thalidomide cause?
Turned out to be a teratogen causing phocomelia (limbs attached too close to the trunk)
What ADRs may be classified as serious?
- Fatal
- Life-threatening
- Prolonged hospitalisation
- Long term disability
- Congenital abnormalities
Medical judgement to identify what may count as serious or not
define adverse drug event
an injury that occurs during treatment, and is not necessarily caused by the drug itself
define adverse drug reaction
response to a drug which is noxious and unintended and which occurs at doses normally used in man - causal link
What are type A ADRs?
Augmented:
- dose related
- predictable (PK and PD)
- common
- reversible
- dose adjustment
Give examples of type A ADRs.
Bleeding - warfarin Hypoglycaemia - diabetes medication
What are type B ADRs?
Bizarre:
- not dose related
- unpredictable
- uncommon
- serious/irreversible
- need to stop treatment
Give examples of type B ADRs.
Anaphylaxis - penicillin Agranulocytosis - clozapine
WHat are the 3 MOA of an ADR?
- Exaggerated response
- Desired pharmacological effect at alternative/additional site (GTN: headache)
- Additional/secondary pharmacological effect (QT length)
- Triggering an immunological response (anaphylaxis)
What were the limitations of early phase clinical trials?
- Small number of patients
- Limited by age and possibly gender
- Selected following precise diagnoses
- Short, well defined duration
- Specialist doctors and continuous follow-up (usually removed from trial if anything unexpected seen)
- Concomitant therapeutics usually excluded
What are the advantages of spontaneous reporting of ADRs?
- Simplicity - all drugs all of the time
- Timely and theoretically inexpensive to administer
- Detects both common and rare reactions
- Accessible by all health care professionals (patients and carers too)
What are the disadvantages of spontaneous reporting of ADRs?
- Inevitable and unquantifiable under-reporting
- Positive bias - serious, unrecognised or new drugs (good)
- Duplication
- Effect of publicity
- Incomplete poor quality data
Define pharmacogenetics.
How individual gene may affect response to drug or drug response on body
