9.1 Sulfa II

Question 1

What is the mechanism of Metronidazole/flagyl?

Answer 1

Small molecule diffuses into cells, once activated releases free radicals that break DNA.

Question 2

What class of bacteria does Metronidazole target? Examples?

Answer 2

Anaerobes- they have the e- txp chain needed to activate free radicals

C. Diff, B. fragilis

Question 3

Do bacteria become resistant to Metronidazole?

Answer 3

Rare-

Question 4

What are the SA of metronidazole?

Answer 4

Nausea, Epigastric dyscomfort
Metallic taste
Furring of tongue
Headache, dizziness, neuropathy – high dose and long duration
Disulfiram – like reaction

Question 5

What is the MOA of bacitracin?

Answer 5

Inhibits cell wall synthesis

Question 6

What does bacitracin cover?

Answer 6

G+ cocci and bacilli
Neisseria; H. flu
Treponema pallidum; Actinomyces; Fusobacterium

Question 7

What doesn’t bacitracin cover?

Answer 7

Enterobacteriaceae; Pseudomonas; Candida; Norcardia

Question 8

How is bacitracin prepared?

Answer 8

PO Only

IV- D/C’d due to nephrotoxicity

Question 9

What is mupirocin?

Answer 9

Topical 2% med

Question 10

What does mupirocin cover?

Answer 10

G+ (i.e. Strep pyogenes & MSSA & MRSA)

G- (i.e. H. Flu; Neisseria; B. Catarrhalis; Pasteurella Multocida)

Question 11

What is the mechanism of mupirosin?

Answer 11

Reversibly inhibits Aminoacyl-tRNA synthetase Prevents AA attaching to tRNA (i.e. prevent “loading” or “charging”)  stop protein synthesis

Question 12

What is the indication for mupirosin?

Answer 12

Nasal MRSA

Question 13

What is the most important characteristics of mycobacterium?

Answer 13

4 layers of cell wall, outer made from mycelia acid
Many efflux pumps
Can hide INSIDE patient’s own cells

Question 14

What are the most common anti-mycobacterial agents?

Answer 14

Isoniazid- most common
Rifamycins- (RNA polymerase)
Some aminoglycosides (streptomycin)
Some macrolides (azithromycin)

Question 15

What is the mechanism of Isoniazid (INH)?

Answer 15

Inhibits mycolic acid synthesis- which makes up the cell wall
Prodrug- diffuses into mycoplasma where activated by KatG that then interferes with mycolic acid

Question 16

What is the indication for INH/Isoniazid?

Answer 16

TB

Question 17

How do cells become resistant to INH?

Answer 17

Mutation of activating enzyme

Question 18

What are the SE of INH?

Answer 18

Rash, fever, dry mouth
Methemoglobinemia
Hepatoxicity (esp. together with 2E1 inducers)
2E1 converts INH to hepatotoxic metabolite
Neuropathy – to prevent give with vit B6
Arthritic symptoms

Question 19

What are special considerations with INH?

Answer 19

Monitor LFTs

Many DDI- induces 2E1 (same as ETOH, many other meds)

Question 20

What is the indication for Pyrazinamide?

Answer 20

Given with INH for TB

Question 21

What is the mechanism of Pyrazinamide

Answer 21

Not fully known
Targets enzymes for synthesis of mycolic acid
Reduction of intracellular pH
Disrupt membrane transport
** Only works at acidic pH

Question 22

What are the SA of pyrazinamide?

Answer 22

Arthralgias, anorexia, N/V
Fever, malaise, dysuria
Hepatotoxicity
Increase uric acid higher risk for gout

Question 23

What is Ethambutol?

MOA

Answer 23

TB drug
Target the synthesis of mycobacterial cell wall
Disrupt the assembly of cell wall

Question 24

What are the SA of ethambutol?

Answer 24

Optic Neuritis –> decrease visual acuity and red-green color blindness
Rash, pruritus
Joint pain, GI upset, HA, dizziness

Question 25

What is the tx for multi-drug resistant TB?

Answer 25

Bedaquiline

Question 26

What is the mechanism of Bedaquiline?

Answer 26

Inhibits bacterial ATP synthase

Question 27

What are the notable SA of bed aquiline?

Answer 27

QT prolongation

Hepatitis