Lecture: antibiotics Flashcards
1
Q
Choice of AB is determined by
A
- susceptibility of bacteria
- main target is staph
- concurrent dz
- depth of infection
- length of tx
- breed
- age
- owner constraints
2
Q
General rules for antibiotic therapy
A
- Select AB with narrow spectrum
- Select AB with wider margin of safety
- Try to never combine AB with glucocorticoids
3
Q
AB for pyo
First line
A
- Erythromycin
- Lincomycin
- Clindomycin
- First gen cephalosporines
4
Q
AB for pyo
Second line
A
- potentiated sulfonamides
- third gen cephalosporins
- amoxicillin/clavulanic acid
5
Q
AB for pyo
Third line (Big guns)
A
- Fluoroquinalones
- Chloramphenicol
- Rifampin
- Amikacin
6
Q
Erythromicin
A
- Macrolide; inhibits ribosomal protein synthesis
- Bacteriostatic, Time-dependent (TID)
- Narrow spectrum for staph
- Vomiting almost a given
- Inhibits cytochrome P450
- absorption delayed by food administration (inactivated by gastric secretions)
7
Q
Lincomycin
A
- Macrolide-like AB
- Bacteriostatic, admin BID
- better absorption/distribution, less vomiting than erythromycin
- rapid resistance
8
Q
Clindamycin
A
- Related to lincomycin, BID
- Absorption not altered by food
- Good penetration in fibrotic tissues
- Skin infection dose 11 mg/kg
- high effectiveness treating methicillin resistent staph
- Well tolerated by most, used frequently for S. schleiferi
- nosocomial infections in people and dogs
9
Q
Cephalosporins
A
- Broad spectrum bacteriacidal
- inhibits synthesis of bacterial cell wall
10
Q
Cephalexin
A
- First generation cephalosporin, broad spectrum but mostly Gram +
- Adverse affects
- GI
- Immune mediated disease
11
Q
Details about second line choices
A
- Potentiated sulfonamides
- Third generation cephalosporins
- broader spectrum good for mixed infections
- Amoxicillin/clavulanic acid
- will not work for s. pseudointermedius
12
Q
Can’t use clavamox if an infection is …
A
methicillin resistent
13
Q
Potentiated sulfonamides
A
- Interfere with synthesis of folic acid
- Immunogenic - triggers hypersensitivity
- type I: IgE mediated (swollen, red)
- type II: cytotoxic (Immune mediated thrombocytopenia)
- type III: immune complex deposition (lupus)
- Antacids interfere with absorption
14
Q
Shifting leg lameness
A
can be adverse affect of sulfas
15
Q
Potentiated sulfonamides
Adverse affects
A
- Anemia, leukopenia, thrombocytopenia
- KCS
- shifting leg lameness (lupus-like joint symptoms)
- hypothyroidism