Mb6-Antimicrobial Agents I

Front 1

What are charac if an ideal antimicrobial agent?

Back 1

Non-allergenic, water soluble, acid stable (oral admin), active in presence of body fluids, widely distributed, bacterialcidal (lethal)

Front 2

What is bacterial static?

Back 2

Only inhibit growth (requires help from host)

Front 3

What are some bacterialcidal agents?

Back 3

Aminoglycosides, beta-lactams, vancomycin, quinolones, rifampin, sulfonamides/trimethoprom

Front 4

What are some bacteriostatic agents?

Back 4

Chloramphenicol, MLS (erythromycin), sulfonamides, trimethoprim, tetracycline

Front 5

Why should a patient finish their prescription?

Back 5

If they stop they just select for resistant strains & killing off competition helps them survive

Front 6

What are the five targets of antimicrobial agents?

Back 6

Cell; wall, ribosome, nucleic acid, enzymes, & membrane intergrity

Front 7

What is the importance of cell walls as targets?

Back 7

Euk cells don't have cell walls or synthesize peptidoglycans.

Front 8

What is the most prominent target in bacterial cell walls?

Back 8

Penicillin binding proteins

Front 9

What is the most prominent antimicrobial?

Back 9

Beta-lactams (target cell walls)

Front 10

What is the signif of ribosomes as targets?

Back 10

Diff than euk ribosomes, typically low toxicity.

Front 11

What are the most prominent antimicrobial in the ribosome class?

Back 11

Aminoglycosides, tetracyclines, chloramphenical, linezolid, erythromycin

Front 12

What is the sig of nucleic acid synthesis as antimicrob target?

Back 12

Diff in euk, few agents in this class (quinilones/fluorquinilones- target DNA gyrase), antiviral/fungal/parasitic in this class

Front 13

What is the signif of enzymes as antimibrob targets?

Back 13

Diff in euk. Metabolic antagonists (specifically target tetrahydrofolic acid THFA)

Front 14

What are the primary antimicrob in the ezyme targeting class?

Back 14

Sulfonamides & trimethoprim (inhib steps in THF synthesis)

Front 15

What is the signif of membranes as antimicrob targets?

Back 15

Can be toxic (limited to topical use) & important antifungals

Front 16

What is the ideal antimicrob agent?

Back 16

Broad-spectrum (active against diverse species). Selective killing is better. No antibiotic is active against everything

Front 17

What is combination therapy?

Back 17

Simultaneous use of multiple antibiotics->inc spectrum of activity, treats mixed infections, treat life-threatening infections, avoids resistance (never use rifampin alone), enhances actividy w/o toxicity

Front 18

What are the 2 important considerations of combination therapy?

Back 18

Synergism (activity is additive) & Antagonism (activity is reductive)

Front 19

What is an example of synergism?

Back 19

Amiglycoside & cell wall inhib. CWI makes cell more permeable for AG to enter

Front 20

What is an example of antagonism?

Back 20

Bacteriostatic & cell wall inhibitor (beta lactams). Erythromycin inhibits growth but penicillin needs growth to inhibit cell wall synthesis

Front 21

What are the 2 kinds of resistance?

Back 21

Intrinsic (defines groups of bacteria; spectrum of activity) & Acquired (defines strains)

Front 22

What are some important distinctions that contribute to intrinsic resistance?

Back 22

Gram + vs -: Presence of outer membrane (size) & porins (solubility) & Aerobic vs anaerobic: No oxidation =no aminoglycoside uptake

Front 23

What are examples of when infection don't respond to meds & require further efforts?

Back 23

Draining an abcess & indwelling medical devices

Front 24

What causes acquired resistance?

Back 24

Specific resistance gene that is not present in all strains of a species->alters cellular pyhysiology or structure

Front 25

Why is aquired resistance more dangerous than intrinsic resistance?

Back 25

Unpredictable, often on mobile element (plasmid or transposon), level of resistance is highly variable

Front 26

What are the mechanisms of acquired resistance?

Back 26

Alter ability of antiboiotics to get in or pump it out. Alter anibiotic or target so they don't bind or acquire gene that makes alt form of target

Front 27

What is Minimum Inhibitory Concentration (MIC)?

Back 27

Amt required to inhibit growth

Front 28

What is Minimum Bactericidal Concentration (MBC)?

Back 28

Amt required to kill 99.9% of viable bacteria (doesn't apply to bacteriostatic drugs)

Front 29

What are breakpoints?

Back 29

Describes levels that define liklihood of therapuetic success (diff for ea drug, involves PCKN & PCDN properties)

Front 30

What is susceptible breakpoint?

Back 30

High propability; (>80%) for response

Front 31

What is resistant breakpoint?

Back 31

Failure is high

Front 32

What is intermediate breakpoint?

Back 32

Success depends on situation

Front 33

How can MIC & MBC be determined?

Back 33

Broth dilution, Kirby-Bauer, or E strips

Front 34

What is empirical therapy?

Back 34

Therapy based on practical experience rather than scientific fact. A fcn of intrinsic resistance. Usually broad spectrum if not combination therapy.

Front 35

What is determinative therapy?

Back 35

Necessitated by acquired resistance. Based on susceptibility testing, wait if you can, adjust toward narrow spectrum & use least expensive