Antimicrobials - Inhibitors of Protein Synthesis

Question 1

True or False: Antimicrobial Inhibitors of Protein Synthesis are mainly Bacteriostatic.

Answer 1

True

Question 2

MOA of Tetracylcines

Answer 2

Reversibly bind 30S subunit of ribosome, preventing attachment of aminoacyl tRNA; enter cell via passive diffusion and active transport and concentrate intracellularly

Question 3

Tetracycline mechanisms of resistance

Answer 3

Enzymatic inactivation, production of proteins that interfere with binding to ribosome, impaired influx or increased efflux

Question 4

Used to treat Syphilis in Penicillin allergic patients

Answer 4

Tetracyclines

Question 5

Part of combination therapy for H.pylori, malaria prophylaxis and treatment, and treatment of plague, brucellosis, and tularemia

Answer 5

Tetracyclines

Question 6

Absorption decreased by divalent cations and milk

Answer 6

Tetracyclines

Question 7

Tetracycline that reaches high concentrations in all secretions

Answer 7

Minocycline

Question 8

Lipid soluble Tetracycline for STDs and Prostatitis

Answer 8

Minocycline; give parenterally

Question 9

AE of Tetracyclines

Answer 9

Hypoplasia and discoloration of teeth, stunting of growth, Photosensitivity

Question 10

Contraindications of Tetracyclines

Answer 10

Category D, children under 8 yoa

Question 11

Glycylcycline with Black Box warning –> last resort treatment

Answer 11

Tigecycline

Question 12

Susceptible to Proteus and Pseudomonas efflux pumps

Answer 12

Tigecycline

Question 13

MOA Tigecycline

Answer 13

Binds 30S ribosomal subunit

Question 14

Contraindications of Tigecycline

Answer 14

Pregnancy, children under 8 yoa

Question 15

Contraindications of Aminoglycosides

Answer 15

Teratogenic (Category D), Myasthenia Gravis

Question 16

AE of Aminoglycosides

Answer 16

Nephrotoxic, Neuromuscular blockade, Ototoxic, and Teratogenic

Question 17

Mechanisms of Resistance to Aminoglycosides

Answer 17

Modification/Inactivation of drug, decreased accumulation, modification of 30S binding site

Question 18

How often are Aminoglycosides given, and why?

Answer 18

Once daily; Post-antibiotic effect + concentration- dependent killing

Question 19

Which drugs do time-dependent killing?

Answer 19

Penicillins and Cephalosporins

Question 20

Lactulose MOA

Answer 20

Nonabsorbable disaccharide degraded by intestinal bacteria to form Lactic Acid; favors NH4+ formation –> acidifying gut lumen and reducing plasma ammonium concentrations

Question 21

AE of Lactulose

Answer 21

Osmotic diarrhea, flatulence, abdominal cramping

Question 22

MOA of Macrolides

Answer 22

Reversibly bind 23S rRNA of 50S ribosomal subunit, inhibiting translocation

Question 23

Macrolide resistance mechanisms

Answer 23

Production of esterase to hydrolyze drugs (enterobacteriacea), modification of ribosomal binding site, decreased membrane permeability, increased efflux

Question 24

Similar binding site to Chloramphenicol and Clindamycin

Answer 24

Macrolides

Question 25

Macrolides with CYP450 inhibition

Answer 25

Erythromycin, Clarithromycin, Telithromycyin

Question 26

Causes Gray baby syndrome (cyanosis)

Answer 26

Chloramphenicol

Question 27

Inhibits CYP3A4 and CYP2C9

Answer 27

Chloramphenicol

Question 28

AE: inhibits mitochondrial ribosomes to cause reversible bone marrow suppression or Aplastic Anemia

Answer 28

Chloramphenicol

Question 29

Active against VRE and used topically for eye infections

Answer 29

Chloramphenicol

Question 30

Resistance mechanisms of Chloramphenicol

Answer 30

Chloramphenicol acetyltransferase inactivates the drug, altered permeability

Question 31

Treatment for Toxoplasmosis of the brain

Answer 31

Clindamycin + Pyrimethamine

Question 32

Alternative treatment for PCP

Answer 32

Clindamycin + Primaquine

Question 33

Endocarditis prophylaxis when allergic to Penicillin

Answer 33

Clindamycin

Question 34

AE: potentially fatal C. difficile infection (pseudomembranous colitis)

Answer 34

Clindamycin

Question 35

Good penetration into abscesses and bone

Answer 35

Clindamycin

Question 36

Has cross resistance with Macrolides

Answer 36

Clindamycin

Question 37

Resistance mechanisms of Clindamycin

Answer 37

Receptor modification or mutation, enzymatic inactivation of drug

Question 38

Acts a weak reversible MAOI

Answer 38

Linezolid

Question 39

Bacteriostatic, but bactericidal against Streptococcus and C. perfringens

Answer 39

Linezolid

Question 40

Long post-antibiotic effect

Answer 40

Streptogramins

Question 41

Inhibits CYP3A4 and penetrates macs and PMNs

Answer 41

Streptogramins

Question 42

Inhibits formation of 70S complex

Answer 42

Linezolid

Question 43

AE: mild bone marrow suppression, optic and peripheral neuropathy, lactic acidosis

Answer 43

Linezolid

Question 44

MOA: Binds and inhibits RNA polymerase

Answer 44

Fidaxomicin

Question 45

Indications of Fidaxomicin

Answer 45

C.difficile colitis in adults

Question 46

Contraindications of Fidaxomicin

Answer 46

Under 18 yoa

Question 47

What are the Streptogramins?

Answer 47

Dalfopristin and Quinupristin

Question 48

Alternative treatments for Hepatic Encephalopathy

Answer 48

Oral Vancomycin, Metronidazole, or Rifaximin