PED1003/L09 Variation to Drugs & Reactions Flashcards
What is an adverse drug reaction?
Noxious or unpleasant unintended consequence of medicinal therapy at a dose intended for therapeutic effect and warrants a withdrawal of a drug
What must be taken into account regarding drug safety? (4)
Severity of adverse drug reaction
Disease
Therapeutic alternatives
Individual perception and acceptance of risk
Name 4 features suggesting a cause and effect relationship between drug administration and adverse drug reaction.
Time sequence between taking drug and adverse reaction
Reaction corresponds to known pharmacology of drug
Reaction stops on cessation of drug
Reaction returns on restarting the drug
What is The Yellow Card/
Documentation regarding adverse drug reactions
How is a side effect different from an adverse effect?
Unavoidable consequence of drug administration (less harmful than adverse drug reaction)
What is a secondary adverse effect?
Indirect causation, secondary to the drug e.g., opportunistic infections due to glucocorticoid therapy
What are the risk factors for adverse drug reactions? (3)
Age
Pregnancy
Co-morbidities
Polypharmacy
Lifestyle
History of allergies
Unknown/unpredictable
What percentage of global trial participants are white, Asian and Black?
76% white
11% Asian
7% black
Describe a type A adverse drug reaction.
Augmented pharmacological effect
Adverse effect that is known to occur from the primary pharmacology of the drug and is usually dose dependent
Describe a type B adverse drug reaction.
Bizarre effects
Adverse effects that are unpredictable from the pharmacology of the drug
Describe a type C adverse drug reaction.
Chronic effects
Occur as a result of chronic treatment of the drug
Describe a type D adverse drug reaction.
Delayed effects
Occur remote from treatment, either in children of treated patients or in patient themselves
Describe a type E adverse drug reaction.
End of treatment effects
Adverse effects occur as a result of stopping the treatment (withdrawal effects)
Give an example of a type A adverse drug reaction.
Bradycardia from treatment with B blocker
Hypoglycaemia from insulin injection
Tachycardia from muscarinic antagonist ipratropium
Give an example of a type B adverse drug reaction.
Anaphylaxis due to penicillin
Bone marrow suppression due to chloramphenicol
TGN1412 Northwick Park - drop in BP, nausea, pain, soft tissue damage, multi-organ failure due to excess cytokine release ‘cytokine storm’
Give an example of a type C adverse drug reaction.
Latrogenic Cushing syndrome from chronic glucocorticoid therapy
Give an example of a type D adverse drug reaction.
Diethylstilbestrol given to pregnant mothers - high incidence of vaginal cancers in offspring in 20s
Isotretinoin (accutane) causes birth defects
Second cancers in response to Hodgkin’s disease treatment
Give an example of a type E adverse drug reaction.
Adrenal insufficiency after glucocorticoid therapy
Describe the normal regulation of metabolism by corticosteroids. (3)
Hypothalamic nuclei releases CRH
Anterior pituitary releases ACTH
Adrenal cortex releases cortisol
Describe adrenal atrophy in response to glucocorticoid treatment. (4)
Exogenous glucocorticoids used for anti-inflammatory or immunosuppressives act on HPA axis
Negative feedback disturbed
Cause adrenal atrophy
Termination of treatment, decreased cortisol
What 2 forms can adverse drug interaction modifications take?
Potentiation
Attenuation
Describe pharmacodynamic interaction of drugs. (2)
Similar or opposing pharmacological effects
E.g., ethanol increasing the sedative effect of antihistamine drugs or certain antidepressants
Describe pharmacokinetic interaction of drugs.(2)
One drug interferes with disposition (e.g., metabolism or excretion of drug) of the other
Monoamine oxidase inhibitors blocking metabolism of dietary amine
What drug inhibits CYP450 and interferes with metabolism of other drugs?
Fluvoxamine
