Chapter 76: Drug Allergies & Adverse Drug Reactions

Question 1

ADRs are categorized into which two types?

Answer 1

Type A: predictable (most ADRs)
Type B: unpredictable

Question 2

Type A reactions are dependent on?

Answer 2

dose

Question 3

Type B reactions include?

Answer 3

• Idiosyncratic reactions (e.g., SJS)
• Drug hypersensitivity reactions
• Drug allergies

Question 4

Type I allergic reactions occur how long after drug exposure?

Answer 4

within 15-30 min

Ex) urticaria, bronchospasm, angioedema, anaphylaxis

Question 5

Type II allergic reactions occur how long after drug exposure?

Answer 5

5-8 days

Ex) hemolytic anemia and thrombocytopenia

Question 6

Type III allergic reactions occur how long after drug exposure?

Answer 6

Over 1 week

Ex) DILE

Question 7

Type IV allergic reactions occur how long after drug exposure?

Answer 7

48 hours to several weeks

Ex) PPD skin test for TB

Question 8

Drugs most associated with photosensitivity

Answer 8

• Amiodarone
• Diuretics
• Methotrexate
• oral and topical retinoids
• Quinolones
• St. john’s wort
• Sulfa drugs
• Tacrolimud
• Tetracyclines
• Voriconazole

Question 9

REMS are developed by _____ and approved by ____ to ensure the benefits of the drug outweighs the risk?

Answer 9

Manufacturer
FDA

Question 10

T/F: if a medication has a MedGuide, it only needs to be dispensed with the original Rx and it’s optional to dispense it with each refill?

Answer 10

False - it must be dispensed with the original rx and each refill

Question 11

When an ADR occurs, which scale can help determine the likelihood that a drug caused an adverse reaction?

Answer 11

Naranjo Scale

Question 12

SE, adverse events and allergies should be reported to the _____?

Answer 12

FDAs MedWatch program, which is called the FDA Adverse Event Reporting System (FAERS)

Question 13

Post-marketing safety surveillance programs is also known as?

Answer 13

Phase IV

Question 14

When dispensing medications that can cause photosensitivity, what should patients be advised to use?

Answer 14

sunscreens that block both UVA and UVB, which are labeled as Broad-spectrum

Question 15

Drugs most commonly associated with photosensitivity?

Answer 15

Amiodarone
Diuretics (thiazide and loop)
MTX
Oral and topical retinoids
Quinolones
St. John’s Wort
Sulfa antibiotics
Tacrolimus
Tetracyclines
Voriconazole

Question 16

What is TTP?

Answer 16

a blood disorder in which clots form throughout the body

Question 17

Key drugs associated with TTP?

Answer 17

Oral P2Y12 inhibitors (e.g., Plavix)
Sulfamethoxazole

Question 18

What is the key to treating SJS and TEN?

Answer 18

stop the offending drug

Question 19

Which medications are CI in TEN, but may be used in SJS?

Answer 19

Systemic steroids

Question 20

Anaphylaxis occurs within what time frame of drug exposure?

Answer 20

seconds to minutes

Question 21

Treatment for anaphylaxis?

Answer 21

Epinephrine injection +/- Benadryl +/- steroids +/- IV fluids

Question 22

Key drugs that are commonly associated with severe skin reactions?

Answer 22

Abacavir
Allopurinol
Carbamazepine
Ethosuximide
Lamotrigine
Modafinil
Nevirapine
PCNs
Phenytoin
SMX

Question 23

Dose for EpiPen?

Answer 23

1 mg/mL

Question 24

Where should EpiPen be injected?

Answer 24

into the middle of the outer thigh

Question 25

At what angle should an EpiPen be injected?

Answer 25

90 degree only

Question 26

How long should the EpiPen needle be held in place when injecting?

Answer 26

3 seconds

Question 27

After removing the EpiPen needle, how long should you massage the area for?

Answer 27

10 seconds

Question 28

T/F: to know you have injected the full amount of EpiPen, there should be no liquid in the device after using?

Answer 28

False - there may be liquid remaining in the device after injection

Question 29

T/F: A second dose of EpiPen can be given in the opposite leg if needed prior to arrival of medical help?

Answer 29

True

Question 30

T/F: EpiPen CANNOT be injected through clothing?

Answer 30

False - it can

Question 31

On the NAPLEX, if a patient is allergic to PCNs, what should be avoided?

Answer 31

all PCN classes should be avoided, with the exception of: Acute otitis media; use of a 2nd or 3rd gen cephalosporin in patients with non-severe PCN allergy (cefdinir, cefpodoxime, ceftriaxone, or cefuroxime)

Question 32

Which medication is considered safe in patients with PCN allergies?

Answer 32

Aztreonam

Question 33

In which disease state should a pregnant person or a person with HIV & a PCN allergy be desensitized and still receive PCN?

Answer 33

Syphilis - PCN G Benzathine (Bicillin LA)

Question 34

Which drugs/classes contain a warning or CI for use in patients with sulfa allergies?

Answer 34

Thiazide & loop diuretics Sulfonylureas Acetazolomide Zonisamide Celecoxib Darunavir

Question 35

T/F: Sulfite or sulfate allergies cross react with sulfonamides?

Answer 35

False - they do not cross react

Question 36

Contrast media used in CT scans can cause?

Answer 36

Anaphylactoid reactions and delayed skin reactions

Question 37

Drugs to avoid with a peanut or soy allergy?

Answer 37

Clevidipine Propofol Progesterone

Question 38

Patients who have true allergy to eggs should avoid which drugs?

Answer 38

Clevidipine Propofol Yellow Fever vaccine

Question 39

T/F: if a severe reaction occurs to an influenza vaccine, regardless of which ingredient is suspected, the patient should not receive further doses of any influenza vaccine formulation?

Answer 39

True

Question 40

What is the most common drug allergy in the US?

Answer 40

PCN allergy

Question 41

What is the goal of penicillin skin testing?

Answer 41

To identify patients who are at the greatest risk of a Type I hypersensitivity reaction

Question 42

Skin testing only predicts what kind of reaction?

Answer 42

IgE-mediated

Question 43

How is desensitization done?

Answer 43

A very small dose of the medication is administered and the dose is increased in increments at regular time intervals up to the target dose

Question 44

What happens if doses are missed during desensitization?

Answer 44

The drug-free period allows the immune system to re-sensitize to the drug and serious hypersensitivity reactions could occur with subsequent doses

Question 45

Desensitization should NEVER be attempted if an agent has previously caused which reactions?

Answer 45

SJS or TEN