Antibiotics

Question 1

Fluoroquinolones- MOA

Answer 1

Inhibition of DNA gyrase and topoisomerase IV (replication)

Question 2

Fluoroquinolones- effect

Answer 2

Bactericidal; concentration-dependent

Question 3

What impairs absorption of fluoroquinolones?

Answer 3

Bivalent and trivalent cations. Al, Zn, Ca (e.g. antacids)

Question 4

Fluoroquinolones- ADRs

Answer 4

Tendinopathy, CNS (aneurysms?), GI, skin (photosensitivity), peripheral neuropathy, prolonged QTc, dysglycemia, mental health

Question 5

Rifampin- MOA

Answer 5

Inhibition of bacterial RNA polymerase (transcription)

Question 6

Rifaximin- uses

Answer 6

Secretory Traveler’s diarrhea (ETEC, IBS-D, hepatic encephalopathy)

Question 7

Macrolides- MOA

Answer 7

Inhibition of 50S ribosome (protein synthesis)

Question 8

Macrolides- effect

Answer 8

Bacteriostatic, concentration-independent, anti-inflammatory

Question 9

Macrolides- interactions

Answer 9

Cytochrome P450 3A4 inhibition (especially erythromycin)

Question 10

Coverage for atypicals like mycoplasma, legionella, chlamydia, treponema, Neisseria

Answer 10

Macrolides

Question 11

Antibiotic options for secretory travelers diarrhea

Answer 11

Fluoroquinolones, macrolides, rifaxamin

Question 12

Sulfonamides/trimethoprim- interactions

Answer 12

CYP 2C8 and 2C9 inhibitor

Question 13

Metronidazole- MOA

Answer 13

Nitro-imidazole, a bactericidal agent after being reduced by anaerobes and protozoans, disrupts DNA of microbes and inhibits nucleic acid synthesis

Question 14

Metronidazole- ADRs

Answer 14

Metallic taste, peripheral neuropathy, headache, GI, dizziness

Question 15

Vancomycin- MOA

Answer 15

Complexes with D-alanyl-D-alanine precursor of pentapeptide cell wall. Interferes with elongation of peptidoglycan backbone.

Question 16

Vancomycin- ADRs

Answer 16

Nephrotoxicity, ototoxicity, Redman syndrome. Generally only with IV administration.

Question 17

Vancomycin- effect

Answer 17

Bactericidal; time-dependent