Adverse drug reactions

Question 1

what is the management of statin induced myalgia?

Answer 1

1. Exclude rhabdomyolysis with CK and urine dip
2. If unacceptable Sx or CK > 2,000 ensure statin is required, if so reduce dose or switch to another with lower risk of myalgia
   
   1. Risk of myalgia (high → low): simvastatin > atorvastatin > pravastatin > fluvastatin or a fibrate

Question 2

Risk of myalgia (high → low) for statins

Answer 2

simvastatin > atorvastatin > pravastatin > fluvastatin or a fibrate

Question 3

what are the 3Cs commonly assocaited with C.Diff?

Answer 3

cephalosporin

ciprofloxacin

clindamycin

Question 4

adverse effects of ACEi

Answer 4

Hypotension, electrolyte abnormalities (↑ K+, ↓ Na+), AKI, dry cough

Question 5

adverse effects of beta blockers

Answer 5

Hypotension, bradycardia, wheeze (asthma), worsens acute heart failure (improves chronic)

Question 6

adverse effects of CCB

Answer 6

Hypotension, bradycardia, peripheral oedema, flushing

Question 7

adverse effects of diuretics

Answer 7

Hypotension, electrolyte abnormalities, AKI, sub-class dependent effects

Spironolactone → gynaecomastia

Question 8

adverse effects of heparin

Answer 8

Haemorrhage (esp. if renal failure or < 50kg), heparin induced thrombocytopenia

Question 9

adverse effects of warfarin

Answer 9

Haemorrhage, pro-coagulant for first few days (need heparin until INR 2)

Question 10

adverse effects of aspirin

Answer 10

Haemorrhage, peptic ulcers, gastritis, tinnitus (large doses)

Question 11

adverse effects of digoxin

Answer 11

Nausea, vomiting + diarrhoea, blurred vision, confusion, drowsiness, xanthopsia (yellow/green visual perception including “halo” vision)

• Hypokalaemia augments digoxin effect
• Hyperkalaemia limits digoxin effect

Question 12

adverse effects of amiodarone

Answer 12

Interstitial lung disease, thyroid disease (hypo and hyper), skin greying, corneal deposits

Question 13

adverse effects of statins

Answer 13

Myalgia, abdominal pain, rhabdomyolysis, ↑ AST/ALT

Question 14

what is a drug that has a synergistic effect with verapamil?

Answer 14

beta-blockers

causes profound hypotension

do not give beta-blockers if giving IV verapamil

Question 15

what drugs have a narrow therapeutic index?

Answer 15

• warfarin
• digozin
• phenytoin
• theophyllin

Question 16

what drug classes need careful dosage control?

Answer 16

antihypertensives

antidiabetic drugs

Question 17

what drug might cause presentation with lactic acidosis?

Answer 17

metformin

Question 18

what drug causes HTN crisis?

Answer 18

monoamine oxidase inhibitors

Question 19

what drugs cause sedation?

Answer 19

• Barbiturates
• Opioids
• Benzodiazepines

Question 20

drugs causing presentation with Sweating, flushing, nausea + vomiting

Answer 20

Metronidazole + disulfiram

Question 21

what should not be co-prescribed with ACEi?

why?

Answer 21

NSAIDs

ACEi relax vessels leaving kidney which causes a small drop in GFR

NSAIDs inhibit prostaglandins which modify the afferent vessel - therefore less dilation and reduced renal perfusion.

Question 22

what antibiotic is contraindicated in methotrexate patients? why?

Answer 22

trimethoprim (and co-trimoxazole contains trimethoprim)

trimethoprim = folate antagonist

taking together can lead to synergistic effect - BM suppression, pancytopenia, neutropenic sepsis

Question 23

what is the reveresal agent for heparin?

Answer 23

protamine

Question 24

what is the brand name for co-amoxiclav?

Answer 24

augmentin

Question 25

how are potentially serious reactions denoted in the BNF?

Answer 25

black dot by them

Question 26

what antibiotic has a potentially serious interaction with warfarin?

Answer 26

erythromycin

can increase INR and risk of bleeding

Question 27

what antibiotics shouldn’t be given to penicillin allergic?

Answer 27

• penicillins
  
  • amoxicillin, ampicillin, amoxicillin-clavulanate, dicloxacillin, nafcillin, piperacillin-tazobactam
• cephalosporins