5 Adverse drug reactions Flashcards
list 3 key determinants of toxicity
drug interactions, altered microbial flora, hypersensitivity
what is an Augmented drug response and how is it managed
where the normal pharmacological response is undesirable
dose-related and predictable and usually managed by dose adjustment
what toxins do C.Diff produce
enterotoxin and cytotoxin
adverse side effect example
diarrhoea with antibiotics, tell patient it’s likely and will most likely be self-limiting, unless there’s blood in it
diarrhoea is significantly associated with which antibiotic
clindamycin
what is a Bizarre or Idiosyncratic drug response
unrelated to pharmacology, unpredictable, rare and often severe. Often related to genetics or immunology
drug hypersensitivity reaction examples (4)
anaphylactic shock (biggest concern), haemolytic anaemia, contact dermatitis, rash with viral infection
describe beta-lactam allergy and what to do if a patient claims they have one
clarify what the patient means and document, if just GI upset then continue to prescribe penicillin If a rash= no more penicillins but try other beta-lactams (cephalosporins and carbapenems) Angioedema (swelling of lower layer of skin)/anaphylaxis= no more beta-lactams, use other class of agent
what is Uticaria
nettle rash
what is Erythematous eruptions
reddening of skin, may resemble measles
what is Toxic epidermal necrolysis and give an example of an antibiotic that can cause this reaction
rare but often fatal with blistering and skin peels off
beta-lactams or sulphonamides
what is Stevens-Johnson syndrome and give an example of an antibiotic that can cause this reaction
fever, rash, blisters
vancomycin or penicillins or sulphonamides
define drug interactions
when the effects of one drug are changed by the presence of another drug, food, drink, or an environmental chemical agent
may increase toxicity or reduce activity
what are 2 possible interaction mechanisms involving CYP enzymes
inhibition and induction
what is enzyme induction and the effect on drugs
increased activity of metabolising enzymes, reduce plasma concentration of drugs
what is enzyme inhibition
reduced activity of enzymes, rapid onset, reverse quickly after stopping drugs which lead to this (antifungal agents)
what is the therapeutic range
the window between toxic and therapeutic drug concentrations
Cephalosporin GI reaction
diarrhoea
Glycopeptide ADR
ototoxic/nephrotoxic
Quinolones ADR
high risk of C.Diff diarrhoea, lowers seizure threshold, tendon damage (rare)
Tetracyclines ADR
deposit in enamel and cause discolouration- dental staining
don’t give in pregnancy and <12 years
Lincosamides (Clindamycin) ADR
High risk of C.Diff diarrhoea
Chloramphenicol ADR
Bone marrow toxicity
