Le29.Intro to Antibiotics

Question 1

MOA of tetracyclins?

Answer 1

Inhibit protein synthesis at ribosome

Question 2

MOA of Erythromycin?

Answer 2

Inhibit protein synthesis at ribosome

Question 3

Side affects of Erythromycin? (2)

Answer 3

1. 3A4 Inhibitor

2. Lots of GI cramping-stimulates the motilin receptor

Question 4

Why do erythromycin and clarithromycin inhibit 3A4, while azithromycin does not?

Answer 4

Erythromycin and Clarythromycin are 14 carbon molecules while azithromycin is a 15 carbon molecule

Question 5

When is clindamycin indicated?

Answer 5

For patients allergic to penicillin with odontogenic infections

Question 6

What serious side affect is associated with clindamycin but can occur with most any antibiotic? What antibiotic is most often used to treat?

Answer 6

Pseudomembranous colitis from C-dificile overgrowth due to antibiotic disproportionally killing normal flora). P. colitis leads to life threatening diarrhea. Tx w/ Metronidazole.

Question 7

Why are sulfonamides so rarely used to tx oral infections?

Answer 7

B/c most odontogenic bacteria are resistant to sulfonamides.

Question 8

Bactrim is a combo of sulfamethoxaxole & trimethoprim. What is its MOA?

Answer 8

Inhibits folic acid, which bacteria require.

Question 9

What drug type should not be given concurrantly with sulfonamides? Why?

Answer 9

Local ester anesthetics can inhibit the action of sulfonamides

Question 10

What 3 bactericidal antibiotics share the MOA of cell wall inhibition?

Answer 10

Penicillins, cephalosporins, and vancomycin

Question 11

Vancomycin is normally given via injection, when is it given orally?

Answer 11

During tx of C-dificile

Question 12

MOA of Metronidazole (flagyl)?

Answer 12

Inhibits DNA synthesis

Question 13

MOA of Quinolones (ex. ciprofloxascin (cipro))?

Answer 13

DNA gyrase inhibitor (prevents unwinding of DNA)

Question 14

When are quinolones generally used?

Answer 14

For GI infection, to prevent Montezuma’s revenge

Question 15

What negative side affects are associated with quinolones?

Answer 15

-Blocks 1A2, therefore raising theophyline (super caffeine, used in asthma tx) levels

Question 16

MOA of rifampin?

Answer 16

Inhibits DNA synthesis

Question 17

When is rifampin indicated?

Answer 17

For TB infections

Question 18

What is the major drug interaction associated with Rifampin? Why?

Answer 18

Rifampin is a 3A4 inducer and therefore can decrease effectiveness of oral contraceptives

Question 19

MOA of Aminoglycosides, such as streptomycin?

Answer 19

Inhibits protein synthesis at ribosome.

Question 20

When are aminoglycosides indicated?

Answer 20

Aminoglycosides are given via injection for individuals with severe gram negative aerobic infections (must be pretty sick b/c aminoglycosides have such a low TI).

Question 21

What are 2 negative side affects of aminoglycosides?

Answer 21

At high blood levels => hearing loss & kidney problems (odo nephrotoxicity)

Question 22

MOA of Nystatin? In what form is Nystatin given?

Answer 22

Nystatin is given as a rinse or lozenge for oral candidas infection and Inhibits cell membrane synthesis; anti-fungal targets ergosterol.

Question 23

MOA of Amphotericin B?

Answer 23

Inhibits cell membrane synthesis; anti-fungal that inhibits ergosterol.

Question 24

When is Amphotericin B indicated?

Answer 24

As a rinse or lozenge for oral candidas infections or IV for life threatening fungal infection.

Question 25

Neg side affects (3) of amphotericin B?

Answer 25

1. Liver Toxicity
2. Seizures
3. Severe Allergic Rxn