Abx "Allergy" Flashcards
B-lactam Type I
IgE
MC - urticarial
Other: pruritis, angioedema, laryngeal edema, wheezing, SOB, presyncope/syncope, hypotension, CV collapse (anaphylaxis)
B-lactam Type II
IgG & C’
Bone marrow suppression
B-lactam Type III
AB (IgG & IgM) -Ag complexes
Serum-like sickness
B-lactam Type IV
T cell - delayed hypersensitivity
MP rash –> SJS/TEN
What is the highest risk for PCN cross-reactivity?
AminoPCNs & Cephalosporins
Sulfa hypersensitivity reaction
Usually characterized by fever +/- MP rash that develops w/in 7-14d
IgE (urticaria, anaphylaxis) and other serious rxn (SJS/TEN/DRESS) are uncommon
What PCN and cephalosporin are we particularly concerned about regarding drug interaction?
Amoxicillin and Cephalexin
If a patient reports an allergy to penicillin and say they got a rash, what can they have? What can they not have?
Use: Ceph, carbapenems, aztreonam if maculopapular
Avoid: PCN
If a patient reports an anaphylactic reaction, what can you use? What must you avoid?
Use: aztreonam or non-B-lactam abx
Avoid: PCN, ceph, carbapenems
How is a hypersensitivity reaction to sulfa drugs typically characterized?
Fever and/or MP rash that develops within 7-14d
You diagnose a patient with HIV. He reports that he had a severe anaphylactic reaction to TMP-SMX in the past. What drug should you avoid in this patient specifically?
Darunavir
What are the 3 groups of sulfonamides?
- Sulfonylarylamines (SMX, HIV PIs like Darunavir)
- Nonsulfonylarylamines (loops/thiazides, tamsulosin, -triptans)
- Sulfonamide-moiety containing drugs (AEDs, HCV PIs like semiprevir)
T/F: Sulfur, sulfites, and sulfates don’t cross-react with sulfonamides
True
What cephalosporin is known for causing serum sickness?
Cefaclor