ID: SHAEER PACKET (PART 4: ANTIMICROBIAL SELECTION FACTORS FOR CONSIDERATION)

Seven host factors to consider during antibiotic selection

1. Age

2. Allergies

3. PK/PD

4. Site of infection

5. Hx of recent antimicrobial use

6. Travel history

7. Pets or animal exposure

PK/PD considerations during antibiotic selection? (four)

1. Pregnancy/lactation (increased Vd, increased CL, may warrant increased dose OR are we avoiding altogether)

2. Genetic abnormalities

3. Comorbidities

4. Immunocompromised

Age-related considerations during antibiotic selection? (three)

1. Decreased eCrCl in neonates, elderly

2. Decreased hepatic function in neonates

3. Alterations in pH in neonates, elderly

Genetic abnormalities examples to consider during antibiotic selection? (two)

1. Slow acetylators of isoniazid -> peripheral neuropathy

2. Glucose-6-phosphate dehydrogenase may cause hemolysis with administration of sulfonamides and nitrofurantoin

Define minimum inhibitory concentration (MIC)

Lowest antimicrobial concentrations that prevents visible growth of an organism within about 24 hours of incubation (values from patient's speciment)

Define minimum bactericidal concentration (MBC)

Lowest concentration at which 99.9% of the inoculum of the organism are killed within 24 hours.

Define MIC90

The value at which 90% or more of the organisms within a test population are inhibited

Define MIC Breakpoints

MIC values that predict probability of treatment success in patient used in clinical and individual patient care

Three limitations of MIC interpretation?

1. Clinician pitfalls; selecting drug with lowest MIC, highest MIC, comparing MICs of different agents

2. MICs of different antibiotics are NOT directly comparable

3. MICs can be impacted by population of bacteria tested versus at site of infection, bacterial growth medium and cation content, antibiotic degree of plasma protein binding

When do we combine antimicrobials?

Serious infections, prevent drug resistance, empiric broad-spectrum of activity, polymicrobial infections

Not sure what else there is to know here

will return and go further in depth