Prudent Use of Antibiotics - Graham Flashcards
About how many antibiotics prescriptions are unnecessary?
Why does this happen, given that 97% of physicians know overuse contributes to antibiotic resistance?
What conditions should Abx not be prescribed for?
Perhaps 50%.
Usually either patients expecting or insisting on receiving them, or physicians trying to cover their asses.
NEVER for common cold. Not for undifferentiated fever.
Distinguish between empiric and directed antibiotic therapy.
Empiric: When the identity of the infection has not been conclusively identified, treat the “most likely culprits”. Broad spectrum use of multiple drugs (more adverse effects, costs)
Directed: Following identification. Narrow spectrum, needingly only 1-2 drugs.
Why is MIC not an adequate justification for choice of antibiotic?
MIC varies from organism to organism for a given drug, and are susceptible to many other factors (combinatorial effects, pharmacogenomics). They don’t exist in a vacuum.
What are Nafcillin and Cefazolin first-line treatments for?
What drugs are not indicated for this?
Nafcillin (oxacillin) and Cefazolin are first-choices for invasive MSSA infection.
Quinolones are not indicated for MSSA.
What are some general adverse effects of antibiotic use?
Antibiotic resistance, allergy/hypersensitivity, C. Diff enterocolitis, various side effects.
Increased costs, blah blah wah wah
What do you do if a patient with a basic G+ infection says he or she is allergic to penicillins?
Grill them, because they’re probably not actually allergic.
If they are, use Aztreonam.
What can quality as “misuse” of an antibiotic?
Given when they are not needed,
Continued when they are no longer necessary,
Given at the wrong dose,
Given for the wrong infection (incl Broad spectrum for known infection)
What is an antibiotic stewardship?
A system of people, informatics and policy which promotes optimal selection and dosing of antibiotics. Meant to improve outcomes while minimizing adverse effects.
What factors should be considered when selecting an antibiotic?
The identity of the infection and spectrum of coverage
Resistances
Formulation, bioavailability, achievable concentrations
Allergy, toxicity
Adherence/convenience and cost.
Other patient comorbidities and drug interactions
What are the most common causes (top 4) of community-acquired pneumonia in the following settings:
Outpatient
Inpatient (non-ICU)
Inpatient (ICU)
Outpatient: Strep pneumoniae, mycoplasma pneumoniae, haemophilus influenzae, chlamydophila pneumoniae
Inpatient (non-ICU): Strep pneu., Mycoplasma pneu., Chlamydophila pneu., Haemophilus influenza; same as outpatient
Inpatient (ICU): Strep pneu., Staph aureus, Legionella, Gram-negatives…
What is the basic course of treatment for outpatient CAP?
Inpatient CAP?
What if the patient is in ICU?
What if a PCN allergy is present?
Macrolide or Doxycycline. FQ or beta-lactam + macrolide if co-morbidities present.
Beta-lactam + macrolide.
ICU? Add a Fluoroquinolone.
PCN allergy? Replace beta-lactam + macrolide with Aztreonam
How are pseudomonal pneumonias treated?
MRSA?
Aspiration pneumonia?
Pseudomonas: Beta-lactams like Pip+Tazo, Cefepime, Meropenem, PLUS a fluoroquinolone (Cipro, Levo).
MRSA: Vancomycin or Linezolid
Aspiration: Clindamycin (for oral anaerobes)
Recall the four classes of beta-lactams.
What role do clavulanate and sulbactam serve?
Penicillins, Cephalosporins, Carbapenems, Monobactams.
Beta-lactam inhibitors, given in conjunction.
What beta-lactams are appropriate to treat pneumococcus?
What else is pneumococcus known as?
Cefotaxime, Ceftriaxone.
Streptococcus Pneumoniae.
What is the mechanism of action of macrolides?
Which are in common use today?
What is their spectrum of action?
Bind the 50S subunit to prevent transpeptidation.
Clarithromycin & Azithromycin (erythro for surgical ileus?)
Broad: G+, G-, and atypical pneumonias.
