20-Antibacterial agents Flashcards
What is empirical theory?
• Empirical Therapy is the practice of using treatment prior to knowing the exact cause of disease. Broad range Antibiotics are a good example of using empirical therapy, to knock out a likely culprit before it has time to get worse. Basically as many bacteria for a certain symptom are treated with similar antibiotics anyway, it doesn’t matter what the bacteria is, because in the end, they’ll be dead anyway.
What is an antibacterial spectrum?
range that an antimicrobial agent has against bacteria, divided into broad/narrow spectrum
What is the bacteriostatic activity?
level that inhibits bacterial growth, MIC (mimum inhibitory concentration) is lowest level that inhibits growth
What is the bactericidal activity?
– level of antimicrobial activity that kills the organism (MBC is lowest level)
What is an antibiotic combination?
combination used that can broaden spectrum, prevent resistant strains, synergize in killing effect
What is antibiotic synergism?
combination that enhances each other’s effects, more than just additive
What is antibiotic antagonism?
combination that decreases each other’s effects
What is beta-lactamase?
an enzyme that hydrolyzes the beta lactam ring, making the beta lactam class of antibiotics ineffective.
What is ESBL? Why is it so dangerous?
• Extended spectrum beta lactamases are the very dangerous type that can spread via plasmid, so they can be moved around easily in a population. These are effective against a broad range of beta lactam antibiotics, and mount an effective resistance against expanded spectrum antibiotics.
What is a narrow spectrum antibiotic?
first generation (which means the first line of antibiotics made for a certain antibiotic, not especially important), is very restricted in the bacteria within its effective range, mostly E. coli, Klebsiella, proteus mirabilis, and mirrors oxacillin in its effect against gram positive cocci.
What are broad spectrum antibiotics?
3rd generation begin to have more broad spectrum activity and has more activity against gram negative, and more resistance to beta lactamases.
What are the 4 main classes of antibiotics?
disruption of the cell wall, inhibition of protein synthesis, inhibition of nucleic acid synthesis, and antimetabolite
What class does penicillin belong to?
disruption of cell wall
Give the mechanism of action of penicillin
Binds to PBPs and enzymes responsible for peptidoglycan synthesis, results in cell wall degradation
What are the 4 main drugs of the antiobiotics that inhibit protein synthesis?
COAT- Clindamycin, Oxazolidinone, Tetracycline, Aminoglycoside
