Adverse Drug Reactions (ADRs)

Question 1

What is an ADR?

Answer 1

• any response to a drug that is noxious & unintended
• occurs at doses normally used in humans for prophylaxis, diagnosis or therapy of disease or for modification of physiological function

NOT including medication errors, overdose, drug abuse, non-compliance

Question 2

What is an ADE? (Adverse drug event)

Answer 2

• any undesirable experience associated w use of medial pdt in a px
• includes ADRs & any other adverse effects
  E.g. medication errors related to prescription/preparation/dispensing/administration

Question 3

What are the 2 types of ADRs?

Answer 3

1. Type A (anticipated, predictable)
   - dose related, most reversible by stopping/reducing dose
2. Type B (unpredictable)
   - rare, not detectable during clinical trial
   - only surface after more widespread use

• diff from patho
• prof say A for asai, B for bueysai

Question 4

Drugs that cause bleeding as an ADR.

Answer 4

1. Aspirin (anti-platelet)
2. Warfarin (anti-coagulant)

Question 5

Drugs that cause sedation as an ADR.

Answer 5

Diazepam (anti-anxiety drugs)

Question 6

Drugs that cause hypoglycemic coma as an ADR.

Answer 6

Insulins (e.g. NPH, regular human insulin)
Oral hypoglycemic agents (e.g. SFU)

Question 7

Drugs that cause tremors as an ADR.

Answer 7

Salbutamol (β2 agonists)

Question 8

Drugs that cause respiratory depression as an ADR.

Answer 8

GA, opioids e.g. morphine(painkiller), codeine(painkiller embedded in cough mixture)

Question 9

Drugs that cause diarrhoea as an ADR.

Answer 9

Antibiotics
- esp broad spectrum AB

Question 10

Drugs that cause nystagmus as an ADR.

Answer 10

LA, anti-epileptic
E.g. carbamazepine

Question 11

Drugs that cause constipation as an ADR.

Answer 11

Opioids, antidepressants e.g. amitriptyline

Question 12

What is the most common Type A ADR

Answer 12

Nausea & diarrhoea

Question 13

What are the 2 types of Type B ADRs

Answer 13

1. Idiosyncratic rxns
   - often linked to genetic anomalies
2. Immunological hypersensitivity/allergic rxns

Question 14

What is an example of idiosyncratic rxns?

Answer 14

• G6PD deficiency
• cannot prescribe certain drugs as it may result in haemolysis
• e.g. malaria

Question 15

What are the characteristics of immunologic response?

Answer 15

1. Prior exposure
2. Onset may be delayed (mins/hrs/days/wks)
3. Can occur w subsequent low doses => not dose related
4. Rxns conform to type I, II, III, IV immunogenic responses

Question 16

Which type of hypersensitivity is related to IgE?

Answer 16

Type I Hypersensitivity
- most common cause of hypersensitivity

Question 17

What does Type I hypersensitivity manifest as

Answer 17

Localised: rash, hives, asthma
Generalised: anaphylactic shock

Question 18

Which type of hypersensitivity is cell-mediated?

Answer 18

Type IV

Question 19

What are some conditions due to Type IV hypersensitivity?

Answer 19

1. Stevens-Johnson syndrome (SJS) (fatal rashes) (<10% body effected)
2. Toxic epidermal necrolysis (TEN) (>30% body affected)
3. Mixed SJS/TEN (10-30% body affected)

Question 20

Type IV hypersensitivity commonly caused by what drugs?

Answer 20

Penicillins, Sulfonamides

Question 21

What is Type IV hypersensitivity caused by?

Answer 21

• delayed hypersensitivity, triggered by activation of specific T-cell CD4, CD8 & cytokines