Antibacterial Agents 4: DNA Function Inhibitors

Question 1

Fluoroquinolones

Drugs

Answer 1

Cipro, gemi, moxi, levo

Stem- floxacin

Question 2

Fluoroquinolones

MoA

Answer 2

Targets DNA gyrase and topoisomerase
Bactericidal
Plasmid mediated resistance

Question 3

Fluoroquinolones

Tissue distribution

Answer 3

Most tissues including lung, bone, myuscle. fat, and can get into CNS is meninges are inflammed

Question 4

Nitrofurantoin

MoA

Answer 4

Reduced by bacterial enzyes that damage Bact. DNA

Used mainly for UTIs because of renal concentration

Question 5

Nitrofurantoin

Pharmacokinetics

Answer 5

Rapid absorption in GI

Renal excretion

Question 6

Nitrofurantoin

Adverse reactions/toxicity

Answer 6

Possibly associated with birth defects, some GI issues, some hypersensitivity

Question 7

Metronidazole

MoA

Answer 7

Transforms into a radical anion that target DNA and breaks/inhibits replication
Bactericidal

Question 8

Metronidazole

Pharmacokinetics

Answer 8

Can be taken PO, 80% bioavailible
Can distribute into CSF and bone
Hepatic metabolism
Can be secreted into breastmilk

Question 9

Sulfonamides

Drugs

Answer 9

Sulfamethoxazole

Question 10

Sulfonamides

MoA

Answer 10

Analogs of PABA that are in the bio pathway for folate synthesis
Bacteriostatic

Question 11

Synergism with Trimethoprim

Answer 11

TMP. Trimetrophrim inhibits DHFH (dihrofolate reductase) which improves sulfa efficacy

Question 12

Sulfonamide

Absorption

Answer 12

Best taken empty stomach

Question 13

Sulfonamides

Distribution

Answer 13

Distributed in body water including CSF, can cross placenta

Binds to plasma proteins, displacing bilirubin

Question 14

Sulfonamides

metab/excretion

Answer 14

N-acetylation, renal excretion

Question 15

Sulfonamides

Adverse reactions/toxicity

Answer 15

Rarely can cause stevens-johnson syndrome (fatal)

Some renal damage