Lesson 5 and 6- Classification and Risk Factors of ADR's

Question 1

Type A (Augmented) Reaction

Answer 1

• Characteristics: Dose-dependent, common, predictable, manageable with dose adjustment.
• Examples: Bleeding (warfarin), hypoglycemia (antidiabetics), headache (nitrates).
• Management: Reduce dose or discontinue therapy.

Question 2

Type B (Bizarre) Reaction

Answer 2

• Characteristics: Idiosyncratic, unpredictable, not dose-related, serious.
• Examples: Anaphylaxis (penicillin), agranulocytosis (clozapine), hepatitis (halothane).
• Management: Stop drug immediately; treat reaction (e.g., antihistamines, steroids).

Question 3

Type C (Chronic) Reaction

Answer 3

• Characteristics: Dose- and time-related, cumulative effects.
• Examples: Osteoporosis (steroids), adrenal suppression (corticosteroids).
• Management: Reduce dose or long-term withdrawal.

Question 4

Type D (Delayed) Reaction

Answer 4

• Characteristics: Lag time after drug use, irreversible.
• Examples: Teratogenicity (anticonvulsants), tardive dyskinesia (antipsychotics).
• Management: Avoid in high-risk populations (e.g., pregnancy).

Question 5

Type E (Withdrawal) Reaction

Answer 5

• Characteristics: Occurs after stopping therapy.
• Examples: Myocardial ischemia (beta-blocker withdrawal), opioid withdrawal.
• Management: Reintroduce drug and taper slowly.

Question 6

Type F (Failure) Reaction

Answer 6

• Characteristics: Due to drug interactions.
• Examples: Digoxin toxicity (with furosemide), phenytoin toxicity (with fluconazole).
• Management: Monitor interactions; adjust doses.

Question 7

Type G (Genetic) Reaction

Answer 7

• Characteristics: Pharmacokinetic/dynamic variability.
• Examples: Antimicrobial resistance, contraceptive failure (enzyme inducers).
• Management: Genetic screening; avoid specific drugs.

Question 8

ADR Risk Factors in Children (Absorption)

Answer 8

• Variable gastric emptying, reduced acid secretion, thin skin (↑ dermal absorption).
• Implications: Higher bioavailability; systemic effects from topical drugs.

Question 9

ADR Risk Factors in Elderly (Renal Excretion)

Answer 9

• ↓ Renal blood flow, glomerular filtration rate, and tubular function.
• Examples: Lithium toxicity, digoxin toxicity.
• Management: Adjust doses based on renal function.

Question 10

Dabigatran (Pradaxa)

Answer 10

• Effect: Serious hemorrhages.
• Mechanism: Thrombin inhibition (anticoagulant effect).
• Management: Monitor renal function; avoid in renal impairment.

Question 11

Clozapine

Answer 11

• Effect: Agranulocytosis.
• Mechanism: Idiosyncratic immune reaction.
• Management: Regular blood monitoring; discontinue if neutropenia occurs.

Question 12

Proton Pump Inhibitors (PPIs)

Answer 12

• Effect: Hypomagnesemia.
• Mechanism: Reduced intestinal magnesium absorption.
• Management: Monitor Mg levels; supplement if needed.

Question 13

Statins

Answer 13

• Effect: Hyperglycemia/diabetes.
• Mechanism: Insulin resistance.
• Management: Monitor blood glucose; lifestyle modifications.

Question 14

Tacrolimus

Answer 14

• Effect: Graft rejection (brand switching).
• Mechanism: Bioavailability variability between formulations.
• Management: Prescribe and dispense the same brand.

Question 15

Halothane

Answer 15

• Effect: Hepatitis.
• Mechanism: Immune-mediated liver injury.
• Management: Avoid in patients with liver disease.

Question 16

Corticosteroids

Answer 16

• Effect: Adrenal suppression.
• Mechanism: HPA axis inhibition.
• Management: Taper doses gradually; avoid abrupt withdrawal.

Question 17

Metoclopramide (Children)

Answer 17

• Effect: Extrapyramidal symptoms.
• Mechanism: Immature blood-brain barrier.
• Management: Avoid or use lower doses.

Question 18

Benzodiazepines (Elderly)

Answer 18

• Effect: Falls, sedation.
• Mechanism: ↑ CNS sensitivity, muscle relaxation.
• Management: Use lowest effective dose; avoid long-term use.