Antimicrobial Anesthesia Flashcards
(85 cards)
Classification & Actions
Classification of antibiotics by mechanism of action
(1) agents that inhibit synthesis of bacterial cell walls, including the β-lactam class (e.g., penicillins, cephalosporins, and carbapenems) and dissimilar agents such as cycloserine, vancomycin, and bacitracin
Classification of antibiotics by mechanism of action
(2) agents that act directly on the cell membrane of the microorganism, increasing permeability and leading to leakage of intracellular compounds, including detergents such as polymyxin; polyene antifungal agents (e.g., nystatin and amphotericin B) which bind to cell-wall sterols; and the lipopeptide daptomycin (Carpenter and Chambers, 2004)
Classification of antibiotics by mechanism of action
(3) agents that disrupt function of 30S or 50S ribosomal subunits to reversibly inhibit protein synthesis, which generally are bacteriostatic (e.g., chloramphenicol, the tetracyclines, erythromycin, clindamycin, streptogramins, and linezolid)
(4) agents that bind to the 30S ribosomal subunit and alter protein synthesis, which generally are bactericidal (e.g., the aminoglycosides)
(5) agents that affect bacterial nucleic acid metabolism, such as the rifamycins (e.g., rifampin and rifabutin), which inhibit RNA polymerase, and the quinolones, which inhibit topoisomerases
Classification of antibiotics by mechanism of action
(5) agents that affect bacterial nucleic acid metabolism, such as the rifamycins (e.g., rifampin and rifabutin), which inhibit RNA polymerase, and the quinolones, which inhibit topoisomerases; and (6) the antimetabolites, including trimethoprim and the sulfonamides, which block essential enzymes of folate metabolism.
General antimicrobial therapy principles
Minimum inhibitory concentration
Killing effects and dosing schedules
Bacteriostatic vs Bactericidal
Concentration-dependent killing
Time-dependent killing
Post antibiotic effect - PAE
Peak concentration matters more than time ? MIC. Amg good example. Effect continues long after antibiotic concentration decline below the MIC. Rifampin and M TB. Inside bacteria binds to RNA polymerase to form stable drug-enzyme complex.
Synergism
Pharmacologic and pharmacokinetic factors
Drug penetration into anatomical compartment
Antibiotic - compartment penetration
Unusual compartments
Conditions that alter pharmacokinetics
Therapeutic monitoring
Selection of antibiotic
Types of therapy
Prophylaxis - prevention
Empirical therapy
Definitive therapy
