ADR

Question 1

What is an adverse drug reaction?

Answer 1

Any response to a drug which is noxious, unintended and occurs at doses used in man for prophylaxis, diagnosis, or therapy.

Question 2

What are some predisposing factors to ADRS? (GASPED)

Answer 2

Genetic
Age-related
Sex-related
Physiological e.g. pregnancy
Exogenous e.g. drugs, food
Disease-related

Question 3

What are the main group classifications of ADRs?

Answer 3

Two main groups
A: Dose-related (augmented)
B: Idiosyncratic (bizarre)

Question 4

What are the other group classifications?

Answer 4

C: Chronic
D: Delayed
E: Withdrawal
F: Failure of therapy

Question 5

What are the features and management of Type A?

Answer 5

Features: common, related to pharmacological action of the drug, predictable, low mortality / high morbidity.
Management: reduce dose or withhold, consider effects of concomitant therapy.

Question 6

What are some pharmaceutical variation causes of Type A?

Answer 6

• Changes in bioavailability
• out of fate formulations
• contamination

Question 7

What are some pharmacokinetic variation causes of Type A?

Answer 7

• liver disease
• renal disease
• cardiac disease
• drug interactions

Question 8

What are some pharmacodynamic variation causes of Type A?

Answer 8

• changes in fluid / electrolyte balance

- drug interactions

Question 9

What are the features and management of Type B?

Answer 9

Features: uncommon, not related to a pharmacological action of the drug, unpredictable, high mortality.
Management: withhold and avoid in future.

Question 10

What are some immunological reactions to Type B?

Answer 10

Allergy e.g. penicillin.

Degradation products of penicillin can combine with body proteins and become antigenic, producing an allergic response.

Question 11

What are some pseudo-allergic reactions to type B?

Answer 11

Reactions that reassemble allergic reactions but for which no immunological basis has been found
e.g. aspirin-sensitive asthmatics, and ampicillin rash.

Question 12

What are the features and management of Type C?

Answer 12

Features: uncommon, related to cumulative dose.
Management: reduce dose or withhold; withdrawal may have to be prolonged.

Question 13

What are Type C effects?

Answer 13

Adaptive effects:

• tolerance / physical dependence: narcotic analgesics, e.g. morphine
• adrenal suppression: corticosteroids, e.g. hydrocortisone
• tardive dyskinesia: antipsychotic drugs, e.g. haloperidol.

Question 14

What is adrenal suppression?

Answer 14

Production and secretion of glucocorticoids are controlled by negative feedback.
Prolonged administration of exogenous glucocorticoids can result in suppression of corticoids synthesis by the adrenal cortex.

Question 15

What are the features and management of Type D?

Answer 15

Features: uncommon, usually dose-related, occurs or becomes apparent some time after the use of the drug.
Management: often intractable.

Question 16

What are the features and management of Type E?

Answer 16

Features: uncommon, occurs soon after withdrawal of the drug.
Examples: opiate withdrawal syndrome, myocardia ischaemia (beta-blocker withdrawal)
Management: reintroduce and withdraw slowly.

Question 17

What are the features and management of Type F?

Answer 17

Features: common, dose-related, often caused by drug interactions,
examples: inadequate dosage of oral contraceptive, particularly when used with specific enzyme inducers (e.g. rifampicin).
Management: increase dosage, consider effects of concomitant therapy.

Question 18

What does pharmacogenetics mean?

Answer 18

The study of the influence of heredity on both the pharmacokinetics of drugs and the pharmacodynamic responses to them.