S1B5 - Intro to Antimicrobial Therapy Flashcards
What are most antibiotics derived from?
Antibiotic
- A substance produced by or a semisynthetic substance derived from a microorganism and able in dilute solution to inhibit or kill another microorganism
What are the three types of antimicrobial therapy?
There are three types of antimicrobial therapy which are employed today:
- Empiric
- Specific
- Prophylactic
If you see a question where you start antibiotics before you really know anything, what type of antimictrobial therapy is that?
Empiric therapy is designed to be initiated as soon as an infection is presumed, usually upon presentation with symptoms of an infection.
If you see a question with a specific bacteria, what kind of antimicrobial treatment do you give? (Emperic, specific or prophylactic?)
Specific therapy usually follows the results of a culture and susceptibility report. At this point you can narrow therapy to a single agent which has activity against the organism.
Using antibiotics during surgery to prevent infection is what kind of antimicrobial treatment? (empiric, specific, or prophylactic?)
Prophylactic Antimicrobial Therapy
- Used for “prevention” of infection when either sterile sites have a chance of being introduced to bacteria (surgery), or in cases where a patient may have a compromised immune system and needs to be protected from infections daily (i.e.… bone marrow transplants)
- You must consider the potential risks which can occur with this type of therapy.
- Adverse drug reactions
- Increase in drug resistance
- Superinfection
In antimicrobial pharmacology, what does MIC represent?
MIC (Minimum Inhibitory Concentration): The lowest concentration of an antimicrobial agent required to prevent visible growth of an microorganism after incubation in artificial liquid media.
In pharmacology, what does AUC/MIC ratio represent?
AUC/MIC ratio: The amount of time that the area of the curve (AUC) of the antibiotic remains above the MIC. Used in pharmacodynamic models to express if an antimicrobial would be effective against a certain pathogen.
What does MBC represent in pharmacology?
MBC (Minimum Bactericidal Concentration: The lowest concentration of agent required to sterilize the medium or to kill 99.9% of the bacterial count after in-vitro placement.
What are bacteriorstatic drugs?
Bacteriostatic: Drugs which reversibly impair replicating ability of microorganisms, need the innate immune system to eradicate microorganisms
What are bactericidal drugs?
Bactericidal: Drugs which irreversibly destroy the ability of a microorganism to replicate, these drugs kill the bacteria without outside assistance from immune system
What does PAE represent in pharmacology?
PAE (Postantibiotic Effect): the persistent effect of an antimicrobial agent on microbial growth following brief exposure of the microorganisms to the antimicrobial agent.
What does selective toxicity mean?
Selective Toxicity: The inhibition or destruction of the infecting organism without damage to the host cells (kill the bad, save the good).
Which type of bacterial killing is involved with drugs that you take bigger doses of, fewer times a day?
A) Concentration-dependent
B) Concentration independent
Concentration-dependent
- Rate and extent of bactericidal action increase with increasing drug concentration.
- Better killing as the concentration increases
Which type of bacterial killing is involved with drugs that you take lower doses more frequently?
A) Concentration-dependent
B) Concentration-independent
Concentration-independent (Time dependent)
- Extent of bacterial killing depends on the time the active drug concentration remains above the MIC.
What is the best way to dose time-independent anitbiotics?
Constant IV
