Drugs and Allergies Flashcards
Immunologically mediated reactions account for ________ of all adverse drug reactions
6-10%
What is a macule?
- flat area of altered colour under 1 cm
What is a patch?
- a large macule over 1 cm
What is a papule?
- elevated solid lesion under 1 cm
What is a nodule?
- elevated solid lesion over 1 cm
What is a plaque?
- elevated flat topped, irregular border over 1 cm
What is a vesicle?
- clear fluid filles blisters under 0.5 cm
What is a bulla?
- large fluid filled blisters over 0.5 cm
What is a pustule?
- a vesicle filled with purulent exudate
What is a wheal?
- an accumulation of dermal fluid
What is an immediate allergic reaction that lasts only 0-1 hours?
- type 1 (severe)
- can possibly be non-immunologic
What is an accelerate allergic reaction that lasts only 2-72 hours?
- may be any type
What is a late allergic reaction that lasts over 72 hours?
- may be any type, but it is rarely type 1
What is red man’s syndrome?
- when you infuse vancomycin too quickly, almost everyone will get the same beefy red rash that looks the same as an allergy
- this is because of the release of histamine from the mast cells in the body
- this happens when there is too fast of an infusion
What other drug will cause red man’s syndrome?
- morphine does the same
If you tolerate the drug for 3 days, and then you have the rash after, then you will not have an _____ type reaction
anaphylaxis
Anaphylaxis is also known as a _____ allergic reaction
type 1
What type of allergic reaction is a cytotoxic type reaction?
- type 2
An immune complex or serum sickness reaction is also known as what kind of allergic reaction?
- type 3
A cutaneous eruption (T cell mediated) is also known as a _____ reaction
type 4
What is the MOA of a type 1 allergic reaction?
- initial exposure to antigen results in a specific IgE antibody production
- preexposure after a period of several weeks is then required
- the drug (and carrier protein) reacts with IgE antibody on the surface of mast cells and basophils resulting in a mediator release
What are the typical symptoms of a type 1 allergic reaction?
- urticaria, laryngeal edema, bronchospasm, and anaphylaxis
Thrombocytopenia can be from _____
heparin
What is the MOA of a type 2 allergic reaction?
- IgG or IgM antibody mediated (hemolytic anemia, thrombocytopenia, granulocytopenia)
- eg. beta lactam hemolytic anemia from high and sustained drug concentrations, usually after 7 days
What are the 3 types of type 2 allergic reactions?
- happen cell reaction
- immune complex reaction
- autoimmune reaction
What is the MOA of a type 3 allergic reaction?
- serum sickness hypersensitivity reaction
- IgG or IgM antibody mediated - form circulating complexed with antigen. Fix complement and then lodge into tissues
- typically these occur 5-21 days after exposure
- cefaclor»_space; amoxicillin
- same as type 2 immune complex reactions (but non-hematologic)
What is a type 3 allergic reaction characterized by?
- fever
- arthralgia
- skin rash
- lymphadenopathy
Type 3 allergic reactions typically appear ____ days after administration of an allergen?
- 5-21 days
What kind of immune cells does type 4 reactions typically involve?
- involve the activation of T cells and may involve several other cell lines as well, such as macrophages, eosinophils or neutrophils