Individual variation to drugs and adverse drug reactions (L25)

Question 1

what is an adverse drug reaction?

Answer 1

a harmful or seriously unpleasant event occurring at a dose intended for therapeutic effect and that calls for a reduction of the dose or withdrawal of the drug

Question 2

drug safety is a relative concept and needs to take what into account?

Answer 2

• severity of the ADR
• the disease
• therapeutic alternatives
• individual perception and acceptance of risk

Question 3

what features suggest a cause and effect relationship between drug administration and ADR?

Answer 3

• time sequence between taking drug and ADR
• reaction corresponds to the known pharmacology of the drug
• reaction stops on cessation of drug
• reaction returns on restarting drug

Question 4

when do ADR usually occur?

Answer 4

relatively quickly

but some don’t show until a child is born

Question 5

what is the yellow card?

Answer 5

used by anyone who believes they may have an ADR

Question 6

what is a side effect?

Answer 6

unavoidable consequence of drug administration - less harmful than an ADR

arising as unwanted action is just an integral as the therapeutic effect to the pharmacology of the drug

can sometimes be on clinical benefit

Question 7

what is a secondary adverse effect?

Answer 7

indirect causation, secondary to the drug

eg. opportunistic infections due to glucocorticoid therapy

Question 8

risk factors of getting an ADR

Answer 8

• age
• sex
• medical history
• disease
• current medication
• ethnicity

Question 9

age as a risk factor

Answer 9

elderly more likely to have increases ADRs
• 3 fold increase over 60
• increased medications
• pharmacokinetic factors

neonates susceptible due to difference in pharmacokinetic factors
• don’t have same expression of phase 2 enzymes
• different fat-water distributions

Question 10

sex as a risk factor

Answer 10

females more susceptible - express hormones in different ways and different amounts

different CYPs

Question 11

medical history as a risk factor

Answer 11

if has ADR to 1 drug, more likely to experience ADR to another drug

Question 12

disease as a risk factor

Answer 12

pharmacokinetic factors

increases chance of getting ADR

Question 13

current medication as a risk factor

Answer 13

drug interactions

changes metabolic reactions

Question 14

ethnicity as a risk factor

Answer 14

intrinsic factors

pharmacokinetic factors
• 90% Japanese ar nefast acetylators
• only 50% of caucasians

pharmacodynamic factors

Question 15

extrinsic risk factors

Answer 15

alcohol

diet

smoking

Question 16

classification of ADRs

Answer 16

A - augmented pharmacological effect

B - bizzarre effects

C - chronic effects

D - delayed effects

E - end of treatment effects

Question 17

A - augmented pharmacological effect

Answer 17

enhanced response that shouldn’t really be seen with the amount of drug administered

Question 18

B - bizzarre effects

Answer 18

adverse effects that are unpredictable from the pharmacology of the drug

Question 19

C - chronic effects

Answer 19

occur as a result of chronic treatment of the drug

Question 20

D - delayed effects

Answer 20

occur remote from treatment, either in the children of the treated patents or in the patient themselves

Question 21

E - end of treatment effects

Answer 21

adverse effects occur as a result of stopping the treatment

withdrawal effects

Question 22

adverse drug interactions

Answer 22

when 1 drug modifies the action of another drug

modification can take the form of:
• potentiation
• attenuation

Question 23

pharmacodynamic interaction

Answer 23

similar or opposing pharmacological effects

Question 24

pharmacokinetic interaction

Answer 24

1 drug interferes with the disposition of the other