Antimicrobial Drugs Flashcards
A low molecular substance produced by a microorganism that inhibits or kills other microorganisms causing little or no damage to itself is called what?
Antibiotic
Any substance (synthetic or natural) that kills or inhibits the growth of microorganisms while causing little or no damage to itself is called what?
Antimicrobial
________ drugs are active against a wide range of microorganisms whereas __________ have limited activity and are useful against a particular species
Broad spectrum, Narrow spectrum
When should treatment be started before collecting and culturing a sample?
when the infection is serious
What are the two major tests used to determine Minimal inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC)?
- Disc Diffusion (MIC)
- Broth dilution (MIC and MBC)
Which type of antibiotics usually have a very similar MIC and MBC?
Bactericidal
Which type of antibiotics have much higher MBC than MIC?
Bacteristatic
Prophylaxis treatment is to __________ whereas Definitive treatment is used when_________
Prevent, the pathogen is identified.
ADME is used in reference to what the body does to a drug which is called what?
Pharmacokinetics (PK)
The drugs affect on the body is called what?
Pharmacodynamics (PD)
What are the two goals of the antimicrobial dose?
1-Achieve a bactericidal concentration at the site
2-Discourage emergence of resistant bacteria
*Should be overkill without causing toxicity in the host
In which growth phase are bacteria most sensitive to antimicrobial intervention?
Log or exponential phase
Bactericidal antibiotics ______ bacteria while bacteriostatic antibiotics ______ bacterial growth
kill, stop
What three things best describe Pharmacodynamic properties of antibiotics?
1-Concentration-dependence
2-Time dependence (rate of killing)
3-Time dependent with persistent effects
The suppression of bacterial growth following antibiotic exposure is called what?
Persistent Post antibiotic effect (PAE)
What are the 5 key rules for treating a serious infection?
1-Begin treatment ASAP (should still culture)
2-Use safest effective drug
3-Use the largest reasonable does
4-Monitor plasma concentration to guide dose/avoid toxicity
5-Continue treatment at least 2 days past “cure” (6-8 wk for CNS, 8-10 wk malaria, 6-12 months TB)
What distinguishes antimicrobials from disinfectants?
selective toxicity (High selectivity = reduced adverse effects. Though some can still have side effects)
The ratio of the dose toxic to the host to the effective therapeutic dose is known as?
Therapeutic index (higher the TI the safe the antibiotic)
An effect on human cells resulting from the same mechanism as the anitmicrobial effect of an AMT is referred to as?
Analogous adverse effects
Iriitation, allergies or other adverse reactions to an AMT is referred to as?
Independent adverse effect
What does ADME stand for?
Absorption
Distribution
Metabolism
Excretion
What are 4 inhibitory examples of antimicrobial target mechanisms?
1-Cell wall
2-Protein synthesis (50s and 30s subunit)
3-Metabolic pathways
4-Nucleic acid synthesis
Why would you use a combination therapy? (5 reasons)
1-mixed infection 2-Improve efficacy 3-uncharacterized serious infection 4-lower drug concentrations 5-delay resistance
Disruption of the micro biome by overuse or poor use of antimicrobial agents can lead to what?
Superinfections
