Drug-Induced Hypersensitivity Reactions

Question 1

Define drug-induced hypersensitivity

Answer 1

A low frequency serious adverse drug reaction with an immunological etiology to an otherwise safe and effective therapeutic agent

Question 2

State the 4 key characteristics of DIHR

Answer 2

Rare, unpredictable, complex, potentially fatal

Question 3

Distinguish between the two types of DIHR

Answer 3

Immediate hypersensitivity: occurs within 1 hour, Type 1, IgE mediated
Delayed hypersensitivity: occurs in over an hour, type 4 or 3, t-cell mediated

Question 4

State the two primary reasons most people who claim to have an allergy to
penicillin actually tolerate the drug.

Answer 4

1. Most patients with penicillin allergy lose sensitivity within 10 years
2. Misdiagnosis or non-allergic reactions.

Question 5

State the two phases of delayed hypersensitivity reactions