1How should you make antibiotic prescribing decisions based on MIC?
You shouldn't, oftentimes MIC is not tested to the exact number, just a less than or greater than, so we don't even know if one is really a lower MIC than another. Even when we have an exact number, they are not reliable, and may differ if more tests are done, so antibiotic descision making should be based on other factors.
2What drugs commonly cause a photosensitivity reaction that is not an allergy?
Quinolones, tetracyclines, trimethoprim/sulfamethoxazole
3What drugs commonly cause GI upset that is not an allergy?
Macrolides, tetracyclines, ampicillin, clindamycin, amox/clavulanate
4Cross-reactivity of floroquinolones?
Lower risk, about 2-5% chance of cross reactivity
5Cross-reactivity of tetracyclines?
lower risk, can be predicted with skin testing or oral dose challenging
6Signs/symptoms of a type I allergic reaction
Itching, rash, hives, angioedema, respiratory distress, cardiovascular findings
7What happens in a type I allergic reaction
anaphylaxis
8What drives type I allergic reactions?
IgE
9Signs/symptoms of a type II allergic reaction
Hemolytic anemia
neutropenia
thrombocytopenia
10What happens in a type II allergic reaction
cell destruction
11What drives type II allergic reactions?
IgG
12Signs/symptoms of a type III allergic reaction
Drug fever
Serum sickness
vasculitis
13What happens in a type III allergic reaction
immune-complex deposition, with or without complement activation
14What drives type III allergic reactions?
IgG
15Signs/symptoms of a type IVa,b, and c allergic reaction
contact dermatitis
maculopapular rash
contact dermatitis
16What happens in a type IVa,b or c allergic reaction
Macrophage, eosinophil, or T-cell activation
17Signs/symptoms of a type IVd allergic reaction
stevens johnson syndrome
toxic epidermal necrolysis
18What happens in a type IVa,b or c allergic reaction
neutrophil activation
19What to avoid in most allergic reactions?
The specific drug that triggered the reaction, may consider using other drugs in the same class
20What to avoid in type IVd reactions?
The triggering drug and the entire class of medications it is in
21When can beta-lactam antibiotics be given to patients even with a proven type I reaction?
After 10 years, about 80% of patients will lose reactivity and may be considered for another trial
22Cross reactivity of beta lactam antibiotics?
Correlates with side-chain similarity
23Cross reactivity of cephalosporins?
very low, 1-2% overall
dependent on side-chains, no common side chains means no increased risk
Common R1 sidechain means ~40% crossreactivity in type I patients and ~20% in type IV
24Cross reactivity of carbapenems?
very low, 1-2%
25Cross reactivity of aztreonam?
No increased risk
26What beta lactams does penicillin share side chains with?
Cefadroxil and cefprozil
27What beta lactams does ampicillin share side chains with?
Cefaclor and cephalexin
28What beta lactams does cefepime share a side chain with?
Ceftriaxone
cefotaxime
cefpodoxime
ceftizoxime
29What beta lactams does ceftazidime share a side chain with?
aztreonam
30What beta lactams does cefazolin share a side chain with?
None, can be given to patients with beta lactam allergies with no increased risk
31What percent of patients with a labeled penicillin allergy are able to tollerate penicillin with no issue?
90-95%
32What drugs are impacted by the ingestion of di/trivalent cations (tums, vitamins, etc)?
Fluoroquinolones, tetracyclines