Svensson Lec 9

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 1

what are the 4 characteristics of DIHR

Answer 1

1. rare (implications)
2. unpredicatable
3. complex
4. potentially fatal

Question 2

what are the 2 types of DIHR

Answer 2

immediate and delayed

Question 3

what is immediate hypersensitivity

Answer 3

• occur within 1 hour
• TYPE 1
• IgE-mediated

Question 4

what is delayed hypersensitivity

Answer 4

• occurs >1 hour
• TYPE 3 and 4
• T cell mediated

Question 5

State 2 primary reasons most people who claim to have an allergy to penicillin can tolerate it.

Answer 5

• 50% of people with IgE-mediated PCN allergy lose sensitivity within 5yr; >80% by 10 yr
  –> loss of immunological memory
• Some patients, rash caused by concurrent viral infection

Question 6

State 2 phases of DIHR.

Answer 6

sensitization
- may occur from prior exposure or earlier in the course of therapy for repeated dosing
effector
- hapten/antigen re exposure

Question 7

Identify the most common organ affected by DIHR.

Answer 7

the skin is the most common

Question 8

Describe how DRESS is differentiated from other DIHR.

Answer 8

CHARACTERISTICS: fever, skin rash, lymphadenopathy, hematological abnormalities, and internal organ involvement
ONSET: 2-8 weeks after start of therapy
MORTALITY: 10%
- Anticonvulsants, antibiotics, and allopurinol
STANDS FOR: drug reaction with eosinophilia and systemic symptoms

Question 9

State the time frame at which most drug eruptions occur.
EXANTHEMAS

Answer 9

1. onset 4-14 days after therapy
2. last 1 week
3. self-limiting
4. virus caused
   –> From penicillins, etc.

Question 10

State the time frame at which most drug eruptions occur.
TEN, SJS, ERYTHEMA MULTIFORME

Answer 10

1. distinct reactions
2. onset 1-3 weeks after start of therapy
3. mortality is 10-30%
4. causative agents: allopurinol, seizure meds