adverse drug reactions Flashcards
what are the rare but dangerous side effects of a statin?
myalgia
rhabdomyolysis - CK may not show this
what are the common side effects of statins?
myalgia abdominal pain increased ALT/AST renal impairment hypokalaemia urinary retention
2 main reactions to gentamicin, vancomycin
nephrotoxicity
ototoxicity
ACEI reactions
hypotension
electrolye abnormalities - high K+
AKI
dry cough
beta blocker reactions
hypotension
bradycardia
wheeze in asthmatics
worsens acute HF
CCB reactions
hypotension
bradycardia
peripheral oedema
flushing
diuretics reactions
hypotension
electrolyte abnormalities
AKI
heparin reactions
hemorrhage - especially in renal failure or if <50kg
warfarin
hemorrhage
- note that warfarin actually has PRO coagulant effect in the first few days!! therefore give heparin alongside warfarin and continue until INR exceeds 2.
why do you prescribe warfarin AND heparin together at first
warfarin actually has PRO coagulant effect in the first few days!! therefore give heparin alongside warfarin and continue until INR exceeds 2.
aspirin reactions
hemorrhage
peptic ulcers
gastritis
tinnitus in large doses
digoxin
N&V diarrhoea blurred vision confusion drowsy XANTHOPSIA - disturbed yellow/green visual perception and halo vision
what do potassium levels affect digoxin?
digoxin competes with K+ at the myocyte to limit NA+ influx. this increases the action potential duration and slows the heart rate.
therefore low potassium levels will increase digoxin effect.
high potassium levels will decrease its effect.
amiodarone reactions
interstitial lung disease - always do CXR before starting
hyperthyroidism or hypothyroidism - therefore check all TFTS before starting
skin greying
corneal deposits
lithium effects
early: tremor
intermediate: tiredness
late: arrhythmias, seizures, coma, renal failure, diabetes insipidus
steroid effects
STEROIDS Stomach ulcers thin skin edema right and left heart failure osteoporosis infection (inc candida) diabetes (commonly causes hyperglycaemia which may progress to diabetes) cushings Syndrome
mineralocorticoids: fludrocortisone effects
hypertension
sodium/water retention
NSAIDS effects
NSAIDS No urine Systolic dysfunction - HF Asthma Indigestion Dyscrasia - clotting abnormality
what are the main enzyme inhibiting drugs?
AODEVICES allopurinol omeprazole disulfiram erythromycin valproate isoniazid ciprofloxacin ethanol sulphonamides
why must you avoid combining beta blocker with verapamil ?
profound hypotension and asystole can occur
what are enzyme inducing drugs?
PCBRAS phenytoin carbamazepine barbituates rifampicin alcohol - chronic sulphonylureas
what should you avoid prescribing in an infection for a patient on methotrexate?
do not give trimethoprim. they are both folate antagonist. both together can give toxicity in the form of bone marrow supression, pancytopenia and neutropenic sepsis.
which antibiotics should not be given in patients taking warfarin?
erythromycin
ciprofloxacin
(because these are enzyme inhibitors)
when do you give vitamin K for a patient on warfarin?
bleeding or INR over 8.
if bleed: give vit K IV, if not bleeding, give orally
if INR is <6 + no bleed, reduce warfarin dose.
if INR 6-8 + no bleed, omit 2 doses and restart at lower dose.
