Antimicrobial Agents Intro Flashcards
What are the 3 classes of antimicrobial agents?
antibacterial
antivirals
antifungals
T-F–life destroys life among the lower species?
True
When was penicillin discovered? by who
1929, fleming
When was sulfanilamide discovered?
1936
The ideal antimicrobial agent acts selectively on what? What 4 ways is this achieved?
- the pathogen and not the host
2. unique cell structure, unique biochem paths, altered component affinities, prodrug converted only by pathogen
Review/memorize the 5 factors that determine cidal vs. static activity
- drug’s mechanism
- microbe’s state of growth
- concentration of drug on organism
- type of microbe
- drug’s spectrum of activity
What is the general rule of thumb for antibiotics in the blood?
should exceed the
MIC by 2-8X to offset tissue barriers to infection site
What does narrow spectrum antibiotic mean?
mainly effective against G+ or G- microbes, lower risk for superinfections
What does extended spectrum antibiotic mean?
affects a variety of G+ and G- bacteria
What does broad spectrum antibiotic mean?
Affects both G+ and G-, and other organisms
Are all the broad spectrum antibacterials bacteriostatic or bactericidal?
bacteriostatic
What reflects the margin of
safety expected when using an antimicrobial agent
at its effective dose?
Chemotherapeutic index
TD50/ED50
Does clinical effectiveness depend on maximal efficacy more or less than potency?
maximal efficacy
Review the list of factors influencing efficacy
- Host-immune function, pharmacokinetics, age, preg, genetics, allergy, eidemiologic exposure, compliance
- Microbe-type and variability, body burden, growth rate, environment/site
- drug drug interaction- synergy, antagonism, PK effects
What are the 3 reasons for antimicrobial drug resistance?
- Misdiagnosis
- inherent microbial resistance
- Acquired microbial resistance