Antibiotics for Physician Assistants - Part I
Updated: 08/07/2016
- Empiric therapy is defined as the initiation of treatment prior to firm diagnosis, and knowing the specific organism causing the infection
- Started only after cultures have been obtained
- Targets likely pathogens and must use local antibiogram
- Broad spectrum means covering both gram positive and gram negative bacteria
- Pharmacokinetics: what the body does to a drug
- Absorption: described in terms of bioavailability (F)
- 100% bioavailable drugs (PO = IV): Linezolid, Fluoroquinolones, Tetracyclines, Azithromycin, Metronidazole, Trimethoprim/Sulfamethoxazole (Bactrim), Rifampin
- Distribution: affected by protein binding, blood flow, molecular size, lipophilicity, inflammation, and fluid status
- Metabolism: occurs primarily in the liver via multiple mechanisms
- Phase I: oxidation/reduction (CYP 450), hydrolysis
- Phase II: glucuronidation, sulfonation, methylation, acetylation, glutathione
- Elimination: primarily renal (glomerular filtration and tubular secretion)
- Most antibiotics require dose adjustment for creatinine clearance (CrCl) <50 mL/min
Cell Wall Synthesis Inhibitors
