Flashcards in adverse drug reactions Deck (18)
what is an adverse drug reaction defined as?
any response to a drug which is noxious, unintended and occur at doses used in man for prophylaxis, diagnosis or treatment
what are the 3 classifications for onset of adverse drug reactions?
acute - within 60 minutes
sub-acute - 1 to 24 hours
latent - >2days
what are the three classifications for the severity of adverse drug reactions?
what are the classifications of adverse drug reactions?
type A - augmented
type B - bizarre
type C - chronic
type D - delayed
type E - end of treatment
type F - failure of treatment
what are some predisposing factors to ADRs?
multiple drug therapy
age - more common in the elderly and neonates
sex- more common in women
renal and hepatic impairment
race and genetic polymorphisms
what are some features of type A ADRs?
normal but augmented response to a drug
due to excess pharmacological action (e.g. bradycardia with beta blockers)
they are dose dependent
resolve when the drug is reduced or stopped
what are some reasons that a type A ADR would occur?
too high a dose
last 2 commonly occur as a result of disease
what factors can affect absorption of a drug?
first pass metabolism
when is liver disease particularly important when considering what drug therapy to use?
when drugs have a narrow therapeutic index
why is it important to determine whether or not a patient is a slow metaboliser?
a number of drugs are metabolised via acetylation - slow metabolisers are more prone to drug toxicity
what is an example of a pharmacogenetic ADR?
peripheral neuropathy with isoniazid
what are the consequences of cardiac failure with regard to ADRs?
reduced drug absorption from the gut due to oedema
poor renal perfusion and decreased GFR
what are the features of an immunological type B ADR?
no relation to the pharmacological action of the drug
delay between exposure and ADR
no dose response curve
can manifest as rash, asthma, serum sickness
what are some features of type C ADRs?
related to the duration of treatment as well as the dose
does not occur with a single dose
what are features of type D ADRs?
can occur sometime after treatment in both the children of patients and the patients themselves
what are some features of type E ADRs?
adverse effects occur when a drug treatment is stopped especially suddenly (rebound phenomena)
what are some example of drugs that would cause a type E reaction when suddenly stopped?