Infectious Disease Quiz Flashcards
General considerations for antibiotic choice (4)
- Cost
- Insurance
- Administration (IV vs PO vs q8 vs q24)
- Patient population (antibiogram)
Medication considerations (5)
- Combination (synergy)
Ex: PCN + Aminoglycosides for pseudonomas - Antibiotic susceptibility
- Empiric therapy
Ex: Vancomycin for pneumococcal meningitis
*Broad spectrums are often used for empiric therapy - Targeted “narrow” treatment
- Diagnostic tests
Diagnostic Tests (7)
- Gram stain (gram negative or positive)
- Cultures (growth of causative organism and susceptibility)
- Serology (titers or antibodies measured)
- CBC (elevation in WBC)
- PCR testing
- Sensitivity testing (some bacteria are resistant to certain antibiotic classes)
- Minimum inhibitory concentration (lowest concentration of antibacterial agent to prevent growth; predicts bacteriological response)
Pharmacokinetic efficacy of antibiotics (3)
Relies on….
- Time-dependent kinetics: the amount of time the serum concentration remains above the MIC
- Concentration-dependent kinetics: the highest concentration in the serum reached, must greatly exceed the MIC
- Post antibiotic efficacy: delayed regrowth of bacteria following antibiotic therapy
Pharmacodynamic efficacy of antibiotics (3)
- Bactericidal –> destroys the microbes
Ex: PCN - Bacteriostatic –> inhibits growth but doesn’t destroy
* Needs an immunological response to eliminate organisms - Both
* Some antibiotics exhibit both properties depending on concentration in the blood
Routes of Administration Considerations for Antibiotics (5)
- Bioavailability
- Severity of infection
- Location of infection
- Organ function
- Drug levels required
Patient considerations when choosing antibiotics (5)
- Age
- Immune function
- Allergies
- Response to antibiotics (improving or worsening?)
- ADEs
Narrow spectrum antibiotics
- Active against limited groups of pathogens
2. Generally, may only work against gram(-) or gram(+) but not both
Broad spectrum antibiotics
- Active against a wide range of pathogens
- Often used for empiric therapy
- Generally, has activity against both gram negative and gram positive
Aerobic vs. anaerobic bacteria
Aerobic: grow and live in presence of oxygen
Anaerobic: grow and live in absence of oxygen
Gram Positive Bacteria Characteristics (5)
- Thick peptidoglycan cell wall
POSITIVE=THICK - Smooth cell wall
- Does NOT contain an outer lipid membrane
- Cocci
- Bacilli
Gram Negative Bacteria Characteristics (6)
- Think peptidoglycan cell wall
NEGATIVE=THIN - Wavy cell wall
- Contains a thick lipid membrane
- Coccobacilli
- Cocci
- Bacilli
Antibiotics that treat gram(+) bacteria (7)
- Aminopenicillin
- First generation cephalosporins (Cefazolin)
EXCEPT for Enterococcus bacteria - Vancomycin
Tx of choice for MRSA - Fourth generation antibiotics (cefepime)
- although these are best for gram negative - Aminoglycosides ONLY in combination with other drugs
- Linezolid (Zyvox)- specific product needed
- Licosamides (Clindamycin)
Antibiotics that treat gram(-) bacteria (7)
- First generation cephalosporins (Cefazolin) treat proteus, E.coli, Klebsiella bacteria
- Second generation cephalosporins (Cefoxitin and Cefuroxime)
- Third generation cephalosporins
- Cefoxatime
- Ceftriaxome
- Cefazidime
- Cefotaxime
- cefpodoxime
- Cefixime
- Cefidinir - Fourth generation cephalosporins exhibit great gram(+) and gram(-) activity BUT are the best for gram(-)
- Drug name: Cefepime - Aminoglycosides
* Used in combo to treat gram(+) such as endocarditis but if it is used alone it’s for gram(-)
- Amikacin
- Gentamicin
- Tobramycin
- Streptomycin - Fluoroquinolones
- Ciprofloxacin, Levofloxacin, Moxifloxacin, Ofloxacin - Monobactam (Aztreonam)
Antibiotics that treat gram positive and gram negative bacteria (6)
- PCN
- ESPCN
- B-lactam/b-lactamase inhibitors
- Cephalosporins – mainly 4th gen but also some 1st
- Carbapenems
- broadest spectrum of all antibiotics** - Sulfonamides (Suflamethoxazole)
Which antibiotics treat pseudonomas? (4)
- Carbapenems
- Imipenem
- Meroenem
- Doripenem
- Ertapenem - Aminoglycosides – Tobramycin especially
- Fluoroquinolones (variable pseudonomas coverage)
- CIPROFLOXACIN IS 1ST LINE AGENT - Some 3rd gen cephalosporins but not all
- Ceftazidime is only one
What antibiotics treat E.Coli? (2)
- 1st generation cephalosporins
- Cefazolin (IV)
- Cephalexin (oral)
- Cefadroxil (oral) - Fluoroquinolones
- Ciproflaxin
- Levofloxacin
- Moxifloxacin
- Ofloxacin