Lecture 15 - Antibiotics 1 Flashcards
Read over chart on slide 6
okay yes will do alrighty
What factors influence infection?
Virulence
Number
Host resistance (systemic or local)
What needs to be considered when selecting antibiotics?
Identification of the organism? (If possible)
Susceptibility of organism to a particular agent
Site of infection
-CNS, brain, bone, prostate
Drug characteristics
-lipid solubility, molecular weight, protein binding
How are pharmacodynamics involved in selection of antibiotics?
Relationship of drug concentration to its anti-microbial effects
How are pharmacokinetics involved in selection of antibiotics?
Drug absorption, distribution, elimination from the body
When is the oral route chosen as ROA?
for infections that are mild and can be treated on an outpatient basis
When is the IV route chosen as ROA?
chosen for the most serious infections (ex. vancomycin is poorly absorbed by the intestine)
When is the IM route chosen as ROA?
if it is needed to act rapidly
When is the topical route chosen as ROA?
if the infection is on the skin surface
Choice of empiric therapy depends on: ??
- Site of infection
- Polymicrobial infection likely?
- Severe headache, rigid neck, sensitivity to bright lights - Meningitis
- Immunocompromised/ immunocompetent (immunocompetent can probably wait for lab results to come back to perform targeted therapy)
- Neutropenia - low levels of neutrophils
- Community vs hospital acquired infection (treat based on what is going around at that time)
- Age
Describe 3 Antimicrobial Uses
Prophylaxis
-usually after surgery (bc it puts patient at high risk for infection)
Therapy
-goal is to kill the microbial infection
Suppression
-goal is to not kill all of the microbial infection (just want to suppress growth so it doesn’t spread to other areas of the body
Bactericidal
Kill bacteria at concentrations achievable in the patient
Bacteriostatic
Arrest the growth and replication of organisms, limiting the spread of infection
How can bacteriostatic be just as effective as bactericidal?
Immune system can take care of the rest once bacteriostatic antibiotic suppresses the growth of the microbe
Describe 2 types of rational dosing
- Concentration dependent killing
- Time-dependent killing (concentration independent)
