Abs Against Gram + Organisms 9/10/15

Question 1

List the glycopeptide antibiotics.

Answer 1

Vancomycin

Dalbavancin

Telavancin

Teicoplanin and Oritavancin (little to no info given)

Question 2

What is the MOA of Vancomycin?

Answer 2

Cell wall synthesis inhibitor

Time-dependent bactericidal activity

**Static against Enterococcus

Question 3

What type of bacteria does Vancomycin target?

Answer 3

GRAM POSITIVE ONLY

Examples:

• MSSA/MRSA
• PRSP/other streptococcus
• Clostridium spp (inc. C. difficile)

Question 4

How should Vancomycin be administered?

Answer 4

IV = systemic infections

Oral = C. difficile colitis

Widely distributed into body tissues/fluids/adipose tissue

Question 5

Describe elimination of Vancomycin from the body.

Answer 5

Elimination half-life depends on renal function

+

NOT removed by hemodialysis

=

Takes a longer time to eliminate with patients on hemodialysis/renal failure

Question 6

What are some clinical uses for Vancomycin?

Answer 6

MRSA infections:

-bacteremia, endocarditis, pneumonia, skin, meningitis

Beta-lactam allergic pts

Infections caused by multi-drug resistant bacteria (PRSP)

Moderate to severe C. diff (orally)

Question 7

What are some major adverse effects of Vancomycin?

Answer 7

Red Man Syndrome:

• Related to rate of IV infusion
• Histamine release = erythematous rash, flushing, pruritus

Nephro/Ototoxicity:

• Common when administered with aminoglycosides
• Higher risk with renal failure, high doses, prolonged therapy

Question 8

What type of bacteria are targeted by Dalbavancin (IV)?

Answer 8

Resistant gram positive organisms

Examples:

• MRSA/VISA
• VRE = Van B and Van C (NOT Van A)
• MRSE/Streptococcus

Question 9

Compare and contrast the MOA of Dalbavancin and Vancomycin.

Answer 9

• Dalba is more potent/cidal than Vanco
• Work similarly to inhibit cell wall synthesis

Question 10

What are some major adverse effects associated with Dalbavancin?

Answer 10

Anaphylaxis

Red Man infusion

Skin reactions

Question 11

What dosing adjustments to Dalbavancin should be made in the following situations:

1. Patient with renal insufficiency
2. Patient on hemodialysis

Answer 11

1. Decrease dose
2. No adjustment needed (not cleared by HD)

Question 12

Compare Telavancin to Vancomycin.

Answer 12

-Usage: complicated SSSI, HAP, VAP (S. aureus)

(hospital and ventilator associated pneumonia)

-AEs: GI symptoms, teratogenic, and more nephrotoxic

Question 13

List the Oxazolidinones and why they were developed.

Answer 13

Linezolid (PO and IV)

Tedizolid (PO and IV)

-Activity against resistant gram positive orgs (VRE, MRSA, VISA)

Question 14

What is the MOA of Linezolid and Tedizolid?

Answer 14

Inhibit Protein Synthesis

Question 15

Is Linezolid bacteriostatic or cidal?

Answer 15

Bacteriostatic

(time-dependent bactericidal against Strep pneumo)

Question 16

What is the spectrum of activity of Linezolid?

Answer 16

Gram Positive Bacteria ONLY

• MSSA/MRSA/VRSA
• Coagulase-negative Staphylococci
• PRSP/other Streptococci
• VRE/other Enterococci
• NO C. diff

Question 17

Describe A, D and E of Linezolid.

Answer 17

Absorption: 100% bioavailable

Distribution: readily penetrates well-perfused tissue (30% CSF)

Elimination: Renally and non-renally = NO adjustment for RI and removed by HD

Question 18

What is Linezolid used for clinically?

Answer 18

Very expensive = Serious/complicated infections caused by resistant gram positive bacteria

• VRE = bacteremia
• MSSA/MRSA/Strep pyogenes = Complicated skin/soft tissue infections
• MRSA = Nosocomial pneumonia

NOT for UTIs

Question 19

What drugs interactions occur with Linezolid and what are the effects?

Answer 19

SSRIs/MAOIs

Serotonin Syndrome:

• hyperpyrexia
• cognitive dysfunction
• seizures
• coma

Question 20

Compare and contrast major adverse effects of Linezolid and Tedizolid.

Answer 20

Similarities:

Nausea, vomiting, diarrhea

Peripheral neuropathy

Differences:

Linezolid = lactic acidosis/thrombocytopenia/anemia

Tedizolid = NO SSRI interaction, dizziness, hematologic, optic neuropathy

Question 21

What are the lipopeptide antibiotics and why were they created?

Answer 21

Daptomycin

Quinupristin-Dalfopristin

-Resistant gram positive orgs

Question 22

What is the MOA of Daptomycin?

Answer 22

Inhibits Protein, RNA and DNA synthesis

Concentration-dependent bactericidal activity

Question 23

List the spectrum of activity and clinical uses for Daptomycin.

Answer 23

Very expensive = Serious/complicated infections caused by Resistant Gram Positive Bacteria:

• MSSA/MRSA/VRSA = skin/soft tissue infections and bacteremia
• CNSt
• PRSP/other streptococci
• VRE/other enterococci = endocarditis, meningitis, osteo

NOT for pneumonia

Question 24

Describe D and E for Daptomycin (IV).

Answer 24

Distribution: readily distributes to well-perfused tissue, 90% protein binding

Elimination: primarily by kidneys,

adjust dose for RI,

NOT removed by HD

Question 25

What are adverse effects and drug interactions for Daptomycin?

Answer 25

AEs: GI, H/a, Injection site reaction, Rash, myopathy

DIs: HMG CoA-reductase inhibitors (increased myopathy)

Question 26

Describe the MOA, Elimination and AEs of Quinupristin-Dalfopristin.

Answer 26

Protein synthesis inhibitors

synergistic effect = Cidal

Cleared by liver

AEs: severe GI intolerance = not often used

Jaundice