Antibiotics III: Inhibitors of Protein Synthesis

Question 1

aminoglycosides

Answer 1

gentamicin, amikacin, streptomycin, neomycin

Question 2

target of aminoglycosides

Answer 2

G- organisms and G+ staph; concentration-dependent

Question 3

active transport across plasma membrane into cytosol is O2-dependent

Answer 3

aminoglycosides

Question 4

drugs that bind to 30-S

Answer 4

aminoglycosides

tetracyclines

Question 5

drugs that bind to 50-S

Answer 5

erythromycin
chloramphenicol
clindamycin
dalfopristin/quinupristin
linezolid

Question 6

long post-antibiotic effect (hours)

Answer 6

aminoglycosides

Question 7

used for resistant bacteremia, sepsis and G+ endocarditis

Answer 7

aminoglycosides (in combo w/ beta-lactams or vancomycin)

Question 8

second-line drug for active TB

Answer 8

streptomycin

Question 9

used in hospitals where resistance to gentamicin and tobramycin is common

Answer 9

amikacin

Question 10

adverse reactions to aminoglycosides

Answer 10

ototoxicity, nephrotoxicity

Question 11

prototype tetracycline

Answer 11

doxycycline

Question 12

prototype glycylcycline

Answer 12

tigecycline

Question 13

tetracycline resistance

Answer 13

increased drug efflux and production of proteins that interfere w/ drug binding to 30S subunit (tigecycline resistant to efflux)

Question 14

distributed widely in bone and teeth

Answer 14

tetracyclines

Question 15

form insoluble chelates with multivalent cations resulting in decreased oral absorption

Answer 15

tetracyclines

Question 16

treatment and prophylaxis of malaria

Answer 16

tetracyclines

Question 17

broad spectrum against aerobic and anaerobic G+ and G- organisms (use declined due to resistance, toxicity)

Answer 17

tetracyclines

Question 18

effective against rickettsial infections, Chlamydia, Lyme disease, anthrax, Mycoplasma pneumonia

Answer 18

tetracyclines

Question 19

adverse effects include discoloration of teeth, renal toxicity, superinfection, hepatotoxicity, photosensitivity

Answer 19

tetracyclines

Question 20

macrolides

Answer 20

erythromycin

azithromycin

Question 21

bacteriostatic (can be bactericidal against highly susceptible strains, high concentrations)

Answer 21

macrolides

Question 22

binds reversibly to 50S; inhibits translocation step of protein elongation

Answer 22

macrolides

Question 23

Resistance: plasmid-encoded methylation of 50S subunit that decreases binding affinity

Answer 23

macrolides

Question 24

used for atypical pneumonias, Bordatella pertussis, diphtheria, chlamydia

Answer 24

macrolides

Question 25

Adverse reactions: cholestatic hepatitis, prolonged Q-T interval

Answer 25

macrolides

Question 26

MOA: similar to macrocodes; block peptide bond formation through interactions at A-site and P-site of 50S

Answer 26

clindamycin

Question 27

Uses: severe group A strep, gas gangrene; b. fragilis; topical for acne

Answer 27

clindamycin

Question 28

Adverse reaction: CDAD

Answer 28

clindamycin (and ciprofloxacin)

Question 29

MOA: binds to peptidyl transferase center of 50S subunit

Answer 29

chloramphenicol

Question 30

broad-spectrum bacteriostatic against G+ (MRSA), G- and anerobes

Answer 30

chloramphenicol

Question 31

resistance due to acetyltransferase that acetylates the drug

Answer 31

chloramphenicol

Question 32

Adverse reactions: gray baby, bone marrow suppression, aplastic anemia

Answer 32

chloramphenicol

Question 33

MOA: binds to unique site of 23S rRNA of 50S subunit and blocks formation of initiation complex (bacteriostatic)

Answer 33

linezolid

Question 34

Uses: VRE and MRSA

Answer 34

linezolid

Question 35

Adverse reactions: myelosupression (weekly blood tests); neuropathy

Answer 35

linezolid

Question 36

Drug interactions w/ MAOIs and SSRIs

Answer 36

linezolid

Question 37

MOA: inhibits peptidyl transferase center of 23S rRNA (50S) and binds same site as macrolides

Answer 37

quinupristin-dalfopristin

Question 38

streptogramins

Answer 38

quinupristin-dalfopristin

Question 39

approved for serious infections caused by VRE

Answer 39

quinupristin-dalfopristin

Question 40

Adverse reactions: hyperbilirubinemia, arthralgia/myalgia

Answer 40

quinupristin-dalfopristin