Antimicrobial Anesthesia Flashcards
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
Mechanisms of resistance
Drug efflux pumps - 5 known types
Multidrug and toxic compound extruder (MATE)
Major facilitator superfamily transporters (MFS)
Small multidrug resistance (SMR) system
Resistance nodulation division (RND) exporters
ATP binding cassette (ABC) transporter
Types of infection
Antimicrobial Prophylaxis for Surgery
CELL WALL ACTING
Beta lactam antibiotics
Side chains of some penicillins (R groups).
MOA - beta lactams
Gram positive vs. Gram negative
Normal synthesis of peptidoglcan schematic
MOA of vancomycin
Penicillin resistance
Penicillin spectrum
PCN adverse effects
Cephalosporins
Cephalosporins
Adverse effects and Resistance
Cephalosporins
Second Generation
Increasing gram negative; cefoxitin, cefotetan also anaerobes
Cephalosporins
Third Generation
Decreasing gram positive, increasing gram negative; ceftazidime, cefotaxime, ceftriaxone
“Bleeding risk”
Cephalosporins
Fourth Generation
Gram positive and gram negative and pseudomonas; cefepime
Cephalosporins
First Generation
Cefazolin - gram positive, some gram negative
Beta lactamase inhibitors
Carbapenems
Vancomycin
“Narrow therapeutic range”
Other glycopeptides
Tetracyclines
Tetracycline resistance and activity
Not to pregnant women or pediatric patients!
Macrolides
Usually for people that can’t take PCN
Macrolide resistance
Macrolide - Erythromycin
Macrolides - Clarithromycin and azithromycin
Clindamycin
Oxazolidinones
Linezolid
Aminoglycosides
Aminoglycoside adverse effects
Quinolones
Quinolones activity and resistance
Sulfonamides
Sulfonamides resistance and activity
Trimethoprim
Trim-Sulfa combination
Antifolate adverse effects
General antibiotic adverse effects
Metronidazole
Mupirocin
Some general adverse effects of antibiotics
How are organisms abx resistant?
How are bacteria abx resistant?
What if patient has penicillin allergy?
Do antibiotics impact oral contraceptive?
What if patient is pregnant?
Surgical prophylaxis
Surgical procedure classification and expected infection rate
Surgical prophylaxis timing
Surgical prophylaxis duration and spectrum
Screening for b lactam allergy
Adverse effects of surgical prophylaxis
SCIP measures
Guidelines for antimicrobial prophylaxis for surgery
