Bacteriostatic inhibitors of bacterial protein synthesis: tetracyclines, macrolides, clindamycin, linezolid

Question 1

Which drug classes are bacteriostatic inhibitors of bacterial protein synthesis (4)

Answer 1

1) tetracyclines
2) macrolides
3) clindamycin
4) linezolid

Question 2

Common Uses of tetracyclines

Answer 2

1) doxycycline- MRSA, PNEUMONIA, CELLULITIS
2) tetracycline, minocycline- acne

• gram +, gram -, MSSA, atypicals
• doxycycline does MRSA

Question 3

MOA of tetracycline

Answer 3

inhibits bacterial protein synthesis

Question 4

ADR of tetracycline

Answer 4

1) tooth mottling- avoid kids
2) GI irritation
3) photosensitivity

Question 5

available tetracyclines (3)

Answer 5

1) tetracycline
2) doxycycline (vibramycin, monodox)
3) minocycline (minocin, solodyn)

Question 6

metabolism/ excretion of tetracyclines

Answer 6

significant absorption chelation can occur and prevents absorption with positive cations ( absorption issues with cations)

• SIMILAR TO WITH FLUOROQUINOLONES

Question 7

3 main macrolides and route of administration

Answer 7

1) azithromycin - oral and IV
2) erythromycin - oral, iv and topical
3) clarithromycin - oral

Question 8

Common uses of macrolides

Answer 8

• gram + and gram - but NO MRSA OR PSEUDOMONAS COVERAGE
  1) azithromycin- upper respiratory infections, pneumonia, COPD exacerbation
  2) ezithromycin - acne,
  3) clarithromycin- not used often
• gram+, gram -, atypicals, MSSA
  similar to cefuroxime + atypicals

Question 9

MOA of macrolides

Answer 9

inhibits bacterial protein synthesis

Question 10

ADR of macrolides

Answer 10

azthromycin- QT prolongation (increased risk of fatal heart rhythms

Question 11

metabolism/ excretion of macrolides

Answer 11

• significant drugs interactions.

CLARITHROMYCIN IS A STRONG CYP 3A4 INHIBITOR (many drug interactions)

Question 12

Clindamycin Uses

Answer 12

1) Gram + and some anaerobes ( like for a aspiration pneumonia or dental abscess)
2) MRSA through the “D test”
3) NO GRAM - coverage ( may warrant double coverage if suspect multi resistant organisms)

• MRSA, MSSA, Gram +, anaerobes

Question 13

Black box warning clindamycin

Answer 13

C. diff colitis

- worry the most about this the most with clindamycin and c.diff, so we don’t use it much in outpatient settings

Question 14

What is a d-test

Answer 14

Checks for susceptible resistance

positive test: blunted effect and has some resistance

Question 15

MOA of clindamycin

Answer 15

inhibits bacterial protein synthesis

Question 16

Routes clindamycin

Answer 16

600 -900 mg for IV dosing (high)
350-400 mg BID (oral)
- iv doses tolerated better ( and bigger dose IV than oral)

Question 17

ADR of Clindamycin

Answer 17

• AAD (antibiotic associated diarrhea)

- Cdiff

Question 18

Metabolism/excretion clindamycin

Answer 18

no heptaic or renal adjustment

Question 19

linezolid (zyvox) uses

Answer 19

1) GRAM + ONLY (like clindamycin)
2) NO anaerobes or Gram 3) MRSA infections, VRE- pneumonia and cellulitis
- RESTRICTED USE IN MOST INSTITUTIONS

• VRE, MRSA, MSSA, GRAM +

Question 20

Linezolid (zyvox) moa

Answer 20

inhibit bacterial protein synthesis

Question 21

contradicitions to linezolid

Answer 21

concurrent use or within 2 weeks of monoamine oxidase inhibitors (mAOIs)

Question 22

linezolid (zyvox)

Answer 22

IV or Oral tabs

Question 23

ADR Linzeolid

Answer 23

diarrhea

Question 24

Metabolism/excretion of Linezolid

Answer 24

1) acts as an MAOI- increased risk of serotonin syndrome in combination with SSRI or SNRI