Adverse drug reactions

Question 1

What are type A reactions?
Give examples

Answer 1

Predictable reactions based on the drugs pharmacology. Dose dependent and reversible upon discontinuation

Sedation, weight gain with APs
EPSEs with dopamine antagonists

Question 2

WHat are type B reactions
Give examples

Answer 2

Idiosyncratic
These are unpredictable reactions not related to the drug’s pharmacology. Type B reactions can include drug allergies and other rare but severe reactions

Clozapine - agranulocytosis
Stevens-Johnson syndrome - lamotrigine

Question 3

What is the classification for allergic reactions?

Answer 3

Gell and Coombs

Question 4

What is a type I reaction ?

Answer 4

Immediate hypersensitivity reactions, which can lead to urticaria, pruritus, angioedema, and anaphylaxis

Question 5

What is a type II allergic reaction?

Answer 5

nvolve the activation of complement proteins and destruction of cells by antibodies. For example, drug-induced haemolytic anaemia or thrombocytopenia can occur with certain psychotropic drugs, though these are rare

Question 6

What are type III allergic reactions?
Give an example

Answer 6

occur when immune complexes (antigen-antibody aggregates) form and deposit in tissues, causing inflammation. An example in psychiatry is drug-induced lupus, which has been associated with antipsychotic medications like chlorpromazine

Question 7

What are type IV allergic reactions?
Give an example

Answer 7

Delayed hypersensitivity reactions mediated by T-cells. Psychiatric medications such as lamotrigine are associated with delayed hypersensitivity reactions, including the severe, potentially life-threatening Stevens-Johnson syndrome.