Adverse Drug Reactions

Question 1

What is the equation for calculating the therapeutic index of a drug?

Answer 1

LD50 / ED50

Question 2

Drugs with a narrow therapeutic window usually have a therapeutic index of less than 2 - give some examples

Answer 2

Digoxin
Theophylline
Warfarin
Lithium
Gentamicin, vancomycin
Carbamazepine

Question 3

What is involved in phase 1 of drug metabolism?

Answer 3

Oxidation, reduction and hydrolysis of the drug via cytochrome P450

Question 4

What is involved in phase 2 of drug metabolism?

Answer 4

Conjugation, excretion in urine/bile

Question 5

Most adverse drug reactions occur in phase 2 of drug metabolism. True/False?

Answer 5

False

Most occur in phase 1

Question 6

What is meant by type A -classified adverse drug reaction?

Answer 6

Predictable, dose-dependent adverse reaction

Question 7

List the different mechanisms of type A adverse drug reaction in the kidney

Answer 7

Pre-renal failure (hypoperfusion)
Renal (acute tubular necrosis)
Post-renal (fibrosis, calculi)
Drug interactions

Question 8

What are the 2 main drugs that can contribute to pre-renal failure?

Answer 8

Diuretics
ACE inhibitors
Both can cause volume depletion and reduced GFR

Question 9

List the main drugs that cause acute tubular necrosis

Answer 9

Gentamicin
Sulphonamides
Aspirin

Question 10

What are the 2 main drugs that contribute to post-renal failure?

Answer 10

Methysergide (cluster headache)

Chemotherapy

Question 11

ACE inhibitors increase the hypoglycaemic effect of which drug used in diabetes?

Answer 11

Sulfonylureas

Question 12

Which drugs can cause/worsen constipation?

Answer 12

Ca channel blockers

Anti-cholinergics

Question 13

Potassium-rich foods react with which drugs?

Answer 13

ACE inhibitors

K-sparing diuretics

Question 14

Vitamin E + K -rich foods react with which drug?

Answer 14

Warfarin

Question 15

What is meant by type B -classified adverse drug reaction?

Answer 15

Idiosyncratic/unpredictable, dose-independent reaction

Question 16

Give examples of type B adverse drug reactions

Answer 16

Rashes
Aplastic anaemia (chloramphenicol)
Hepatic necrosis (halothane)

Question 17

Type B adverse drug reactions have high mortality. True/False?

Answer 17

True

Question 18

What is meant by type C -classified adverse drug reaction?

Answer 18

Adverse effect from prolonged therapy

Question 19

Give examples of type C adverse drug reaction

Answer 19

Cushing’s disease (steroids)
Diabetes (B-blockers)
Hypertension (NSAIDs)

Question 20

List the three main risk factors for adverse drug reactions

Answer 20

Elderly and frail
Multimorbidity (renal/hepatic clearance)
Polypharmacy

Question 21

What is meant by type D -classified adverse drug reaction?

Answer 21

Remote from treatment

Many years after stopping

Question 22

Give examples of type D adverse drug reaction

Answer 22

Teratogenic e.g. ACEi in pregnancy

Carcinogenic

Question 23

What is meant by type E -classified adverse drug reaction?

Answer 23

Abrupt withdrawal causing rebound effects

Question 24

Which method is used to report adverse drug reactions?

Answer 24

Yellow card scheme

Question 25

What are the sick day rules? Which medications should be stopped when this criteria is met?

Answer 25

Vomiting or major diarrhoea/ fever, shakes, sweats for >24 hours (visit GP/NHS 24/ nurse/ pharmacist if >48 hours)
ACEi/ARB, NSAIDs, diuretics, metformin

Question 26

Give examples of type E adverse drug reaction

Answer 26

B blockers and rebound tachycardia
Steroids and Addisonian crisis
Anticonvulsants and epilepsy frequency