77. Drug Allergies + ADRs Flashcards
T/F: Type B reactions are most common and account for an estimated 85% of ADRs
False - Type A
___ reactions are dose-dependent, related to the known pharmacologic properties of the drug
Type A
___ reactions are not dose-dependent, are unrelated to pharmacologic actions of the drug, and can be influenced by patient-specific factors (e.g. genetics)
Type B
Give 3 examples of Type B reactions
Drug allergies
Drug hypersensitivity reactions (DHRs)
Idiosyncratic reactions (genetic differences)
Describe Types of Drug Allergies: Type 1 Reactions - Immediate
Immediate, IgE-mediated, ranging from minor local reactions to severe systemic reactions
Examples: urticaria, bronchospasm, angioedema, anaphylaxis
Describe Types of Drug Allergies: Type II Reactions - Delayed
Antibody-mediated, usually 5-8 days after exposure
Examples: hemolytic anemia, thrombocytopenia
Describe Types of Drug Allergies: Type III Reactions - Delayed
Immune-complex reactions, occurring ≥ 1 week after exposure
Example: serum sickness
Describe Types of Drug Allergies: Type IV Reactions - Delayed
T cell-mediated, occurring 48 hours to weeks after exposure
Example: SJS
Key Drugs a/w Photosensitivity
Amiodarone
Diuretics (thiazide and loop)
Methotrexate
Oral and topical retinoids
Quinolones
St. John’s wort
Sulfa drugs
Tacrolimus
Tetracyclines
Voriconazole
____ is a blood disorder in which clots form throughout the body.
Thrombotic thrombocytopenic purpura (TTP)
What is the difference between papules vs macules vs purpura vs petechiae
Papules are raised spots
Macules are flat spots
Purpura are red/purple skin spots (lesions) d/t bleeding underneath the skin (small and large spots)
Petechiae are pinpoint in size
What are common drugs that can cause TTP?
oral P2Y12 inhibitors (e.g. clopidogrel) and sulfamethoxazole
Define ecchymosis
Large bruised area
Define hematoma
A collection of blood under the skin d/t trauma (injury) to a blood vessel, resulting in blood leaking into surrounding tissue
____ is used to reverse bronchoconstriction if the patient is wheezing or has other signs of trouble breathing
Epinephrine
___ can cause a non-IgE-mediated release of histamine from mast cells in the skin, causing itching and hives. This is often when this drug is given to patients who have never used it before or given at higher than normal doses. Pre-medication may be required.
Opioids
___ can cause a direct release of histamine from cutaneous mast cells, causing flushing, hives, and sometimes hypotension is infused too rapidly. Can be avoided by slowing infusion rate.
Vancomycin
Patients positive for ___ are at an increased risk for abacavir hypersensitivity
HLA-B*5701