Adverse Drug Reactions

Question 1

define

Answer 1

undesirable reaction that results in detriment to the wellbeing of the patient when absence of another explanation

Question 2

who is this more common in?

Answer 2

elderly
frail
multimorbid (renal/ hepatic clearance)
polypharmacy

Question 3

drugs with a narrow therapeutic index

Answer 3

theophylline
warfarin
lithium
digoxin
gentamicin
vancomycin
phenytoin
cyclosporin
carbamazepine
levothyroxine

Question 4

phases of drug metabolism

Answer 4

• Phase 1= usually through CYP450 with oxidation, reduction and hydrolysis (ADRs)
• Phase 2= conjugation (water soluble) enables excretion in urine and bile

Question 5

classification

Answer 5

1) Type A= augmented pharmacological effects- dose dependent and predictable
2) Type B= bizarre effects (or idiosyncratic)- dose independent and unpredictable
3) Type C= chronic effects
4) Type D= delayed effects
5) Type E= end-of-treatment effects
6) Type F= failure of therapy (all?)

Question 6

type A causes of pre-renal AKI

Answer 6

diuretics or ACEI/ARB sick day rules (hypotension/hypovolvaemia)

Question 7

type A renal causes (tubular necrosis- ATN)

Answer 7

gentamicin
sulphonamides
aspirin

Question 8

post renal type A causes

Answer 8

fibrosis
calculi
e.g. methysergide and chemotherapy

Question 9

type A drug-drug interactions

Answer 9

 Theophylline and macrolides (P450 inhibited by macrolides so toxicity of theophylline increased). Statins and macrolides are the same.
 Statins and fibrates = myalgia
 TCAs and type 1 AADs= ventricular arrhythmias
 Warfarin and multiple drugs = CYP450
 ACEI increase hypoglycaemic effect of SUs
 Clopidogrel and PPIs
 Herbal alternatives e.g. grapefruit juice

Question 10

type A drug-disease interactions

Answer 10

 Patients with Parkinson’s has increased drug-induced confusion
 NSAIDs/COX-2/TZDs can exacerbate HF (fluid retention)
 Urinary retention in BPH exacerbated by nasal decongestants and anticholinergics
 Constipation is worsened by CCBs and anticholinergics.
 Neuroleptics, tramadol and quinolones lower seizure thresholds
 Beta blockers and asthma

Question 11

type A drug-food interactions

Answer 11

 K+ rich e.g. bananas interact with ACEI, ARB and potassium-sparing diuretics.
 Vitamin E and K= warfarin
 Alter pH e.g. chicken, milk, soy (some drugs react a certain environment to be absorbed) e.g. antibiotics, thyroid medications, digoxin and diuretics
 Grapefruit, cranberry (CYP450) interacts with statins and antihistamines

Question 12

cause of type B

Answer 12

genetic differences between patients

Question 13

examples of presentation of type B

Answer 13

drug rashes
bone marrow asplasia (chloramphenicol)
hepatic necrosis (halothane)

Question 14

type C cause

Answer 14

prolonged therapy

Question 15

examples of type C

Answer 15

steroids=Cushing’s
beta blockers= diabetes
NSAIDs= hypertension

Question 16

what to do before starting medication that cause potentially type C reactions

Answer 16

warn patients

monitoring

Question 17

type D cause

Answer 17

teratogenic and carcinogenic effects of some drugs

Question 18

examples of Type D reactions

Answer 18

secondary malignancy post-chemo and craniofacial abnormalities in children of women taking isotreinoin/ thalidomide

Question 19

type E cause

Answer 19

abrupt withdrawal leading to rebound effects

Question 20

examples of type E

Answer 20

beta blockers= angina
steroids= Addisonian crisis
anticonvulsants= epilepsy

Question 21

black triangle meaning in BNF

Answer 21

caution

Question 22

yellow card scheme

Answer 22

report patient reaction (even if predicted)

Question 23

what issues do NSAIDs cause with the kidneys

Answer 23

• issues in RAS
• hypersensitivity
• interstitial nephritis
• precipitate minimal change GN
• precipitate membranous GN

Question 24

other substances are directly toxic to kidneys

Answer 24

urate
calcium
amyloid

Question 25

who can hyperuricaemia occur in?

Answer 25

leukaemia patients on aggressive chemotherapy

Question 26

what conditions are associated with hypercalcaemia

Answer 26

multiple myeloma
amyloid deposition

both are toxic to kidneys