Adverse reactions Flashcards
side effect vs adverse reaction?
side effect
- predictable unwanted effect
- due to drugs actions in other parts of body
- eg piriton causes drowsiness
adverse reaction
- unpredicted and potentially harmful effects
- caused by administration
- eg allergic reaction
drug interactions?
polypharmacy = use of a combination of drugs
drugs can combine
- so one can have effect on the other
- or they can affect one another
can occur
- outside of body
- after administration
- any stage during pharmacokinetics process
the more drugs administered the greater the chance of an interaction occurring
sometimes a known drug interaction is employed to increase therapeutic effect
summation?
when two different drugs are given and response is equal to if given separately
1 + 1 = 2
synergism?
when two different drugs are given and the response has a greater effect than if given separately
1 + 1 = 3
potentiation?
an ineffective drug enhances the effect of an effective drug
common in antimicrobials
0 + 1 = 2
causes of adverse reactions?
inappropriate dosing - human error
- miscalculation
- patient factors (eg dehydrated / liver disease)
- concurrent therapy (already on other drugs causing interactions)
idiosyncratic reaction (unexpected)
- less common
- more dangerous because unpredictable
- not proportional (eg react to any amount of allergen)
adverse reaction
classification A
augmented (inappropriate dosing)
- enhanced drug effect
- predictable
- dose dependant
- common
- low mortality
adverse reaction
classification B
bizarre (idiosyncratic)
- allergic reaction
- unpredictable
- not dose related
- high mortality
adverse reaction
classification C
chronic (inappropriate dosing)
- due to continuous drug therapy
adverse reaction
classification D
delayed (inappropriate dosing)
- occurs a long time after treatment
adverse reaction
classification E
end of treatment (inappropriate dosing)
- occurs on withdrawal of therapy
reducing drug interactions and reactions?
be familiar with common interactions/reactions
patient observations to detect reaction early
report suspected drug reaction to VS immediately
store drugs according to manufacturer’s instructions
ensure stock rotated correctly
monitor environmental temperatures in pharmacy
pharmacovigilance?
involves ongoing monitoring of:
- suspected lack of drug efficacy
- medicine residues in animal products
- adverse events
if a suspdcted adverse reaction os noted then needs to be reported
aims of pharmacovigilance?
Identify unknown risks associated with the drug
Evaluate the effect the new risks have on benefit:risk balance of the product
Propose suitable mitigation measures to reduce risks
If any risk is too large to be mitigated then sale of product should be stopped
Communicate the outcome of investigations
suspected adverse reaction (SAR)?
can be reported by anyone involved in the marketing of veterinary medicines
- should report to VMD or directly to the manufacturer
- under the VMR
MA holders have a legal obligation to record all information they receive about an adverse event
ensures animal and human health are protected and that veterinary medicines are safe and effective
