Gram + Antibiotics

Question 1

Vancomycin MOA

Answer 1

Inhibits synthesis and assembly of the second stage of cell wall synthesis

Binds to D-Alanyl- D- Alanine preventing further elongation of peptidoglycan

Very slow killer (Bactericidal) takes time to see improvement

Question 2

Vancomycin MOR

Answer 2

VRE & VRSA due to modification of D-alanyl-D-alanine binding site of peptidoglycan. D-alanine is replaced by D-lactate

3 phenotypes (vanA, vanB, vanC)

VISA- thickens cell wall

Question 3

Vancomycin Absorption

Answer 3

IV in systemic infection

Absorption from GI is negligible after oral administration

Question 4

Vancomycin Distribution

Answer 4

Distributed into body including FAT

Used for infections everywhere (including CSF)

Takes 1 hour to distribute from plasma into tissue compartments (Check peak 60 min after the end of infusion)

Question 5

Vancomycin

Answer 5

Not removed by hemodyalisis

Renal elimination that depends on kidney function

Question 6

Vancomycin Targets

Answer 6

MSSA

MRSA

PRSP

C. Diff

Gram +’s. Use if allergic to penicillins

Question 7

Vancomycin Side Effects

Answer 7

Red- Man Syndrome

Flushing, pruritus, erythematous rash on face, neck, and upper torso within 5 min. of starting infusion (Histamine release)

Related to the RATE of intravenous infusion so decrease the rate or discontinue and the rash should go away.

If with AMINOGLYCOSIDES + VANCO be careful with nephro and ototoxicity

Question 8

Dalbavancin MOA

Answer 8

D-ala-D-ala binding, inhibits cross linking and prevents bacterial wall synthesis

More potent than Vancomycin

Question 9

Dalbavacin Dosing

Answer 9

IV only

Long half life so only once weekly

Decreased dose with CrCl (Kidney issues)

Question 10

Dalbavacin Side Effects

Answer 10

• anaphylaxis
• Red man syndrome
• Increased ALT
• Hematologic

Question 11

Telavancin

Answer 11

Vancomycin derivative

Used for Staph Aureus

Question 12

Televancin Side Effects

Answer 12

Higher renal toxicity than vanco

Teratogenic

Question 13

Televancin Dosing

Answer 13

IV 7-21 days

Adjust for renal failure

Question 14

Linezolid MOA

Answer 14

Inhibits protein synthesis (Bacteriastatic & cidal vs. strep pneumo- time dependent bactericidal activity)

Binds to 50S ribosomal subunit near the surface interface of 30 S subunit causing inhibition of the 70 S initiation complex

Question 15

Linezolid MOR

Answer 15

Alterations in ribosomal binding site

Question 16

Linezolid Absorption

Answer 16

Post Effect for S. Aureus and S. Pneumo

100 % bioavailable

CSF Penetration good

Question 17

Linezolid Elimination

Answer 17

Renally and non renally (primarily metabolized) No adjustment for GI

Question 18

Linezolid Drug interactions

Answer 18

Adrenergic or Seratonergic agents

-SSRIs/MAOIs: Hyperpyrexia, cognitive dysfunction, seizures

Question 19

Linezolid Adverse Effects

Answer 19

Lactic acidosis

Peripheral neuropathy

Thrombocytopenia or anemia: if you drop the medication, the platelet count will increase

Question 20

Daptomycin MOA

Answer 20

Binds to bacterial membranes, rapidly depolarizes membrane potential and inhibits protein syntehsis and DNA and RNA syntehsis

CONCENTRATION DEPENDENT BACTERICIDAL ACTIVITY

Question 21

Daptomycin MOR

Answer 21

altered cell membrane binding

Question 22

Daptomycin Elimination

Answer 22

Kidney and need to adjust for renal insufficiency

Question 23

Daptomycin Adverse Effects

Answer 23

Do not use when patient has pneumonia, resort to vanco and if the patient is allergic, use linezolid

Myopathy and CPK elevation

Question 24

Drug interactions Daptomycin

Answer 24

HMG-CoA reductase inhibitors (Statins)

Question 25

Quinupristin-Dalfopristin

Answer 25

End of line resort for gram + when the patient can’t tolerate vanco, linezolid, daptomycin, televancin, dalabavancin, Tedizolid