adverse drug reactions

Question 1

what are the rare but dangerous side effects of a statin?

Answer 1

myalgia

rhabdomyolysis - CK may not show this

Question 2

what are the common side effects of statins?

Answer 2

myalgia
abdominal pain 
increased ALT/AST 
renal impairment
hypokalaemia
urinary retention

Question 3

2 main reactions to gentamicin, vancomycin

Answer 3

nephrotoxicity

ototoxicity

Question 4

ACEI reactions

Answer 4

hypotension
electrolye abnormalities - high K+
AKI
dry cough

Question 5

beta blocker reactions

Answer 5

hypotension
bradycardia
wheeze in asthmatics
worsens acute HF

Question 6

CCB reactions

Answer 6

hypotension
bradycardia
peripheral oedema
flushing

Question 7

diuretics reactions

Answer 7

hypotension
electrolyte abnormalities
AKI

Question 8

heparin reactions

Answer 8

hemorrhage - especially in renal failure or if <50kg

Question 9

warfarin

Answer 9

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.

Question 10

why do you prescribe warfarin AND heparin together at first

Answer 10

warfarin actually has PRO coagulant effect in the first few days!! therefore give heparin alongside warfarin and continue until INR exceeds 2.

Question 11

aspirin reactions

Answer 11

hemorrhage
peptic ulcers
gastritis
tinnitus in large doses

Question 12

digoxin

Answer 12

N&V 
diarrhoea
blurred vision 
confusion 
drowsy
XANTHOPSIA - disturbed yellow/green visual perception and halo vision

Question 13

what do potassium levels affect digoxin?

Answer 13

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.

Question 14

amiodarone reactions

Answer 14

interstitial lung disease - always do CXR before starting

hyperthyroidism or hypothyroidism - therefore check all TFTS before starting

skin greying

corneal deposits

Question 15

lithium effects

Answer 15

early: tremor
intermediate: tiredness
late: arrhythmias, seizures, coma, renal failure, diabetes insipidus

Question 16

steroid effects

Answer 16

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

Question 17

mineralocorticoids: fludrocortisone effects

Answer 17

hypertension

sodium/water retention

Question 18

NSAIDS effects

Answer 18

NSAIDS 
No urine
Systolic dysfunction - HF
Asthma
Indigestion 
Dyscrasia - clotting abnormality

Question 19

what are the main enzyme inhibiting drugs?

Answer 19

AODEVICES
allopurinol 
omeprazole
disulfiram 
erythromycin 
valproate
isoniazid
ciprofloxacin 
ethanol 
sulphonamides

Question 20

why must you avoid combining beta blocker with verapamil ?

Answer 20

profound hypotension and asystole can occur

Question 21

what are enzyme inducing drugs?

Answer 21

PCBRAS
phenytoin
carbamazepine
barbituates
rifampicin 
alcohol - chronic
sulphonylureas

Question 22

what should you avoid prescribing in an infection for a patient on methotrexate?

Answer 22

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.

Question 23

which antibiotics should not be given in patients taking warfarin?

Answer 23

erythromycin
ciprofloxacin
(because these are enzyme inhibitors)

Question 24

when do you give vitamin K for a patient on warfarin?

Answer 24

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.

Question 25

what is protamine used for?

Answer 25

reverse heparin