Staph Hunters

Question 1

What are the Staph Hunters?

Answer 1

• Quinopristin/dalfopristin (IV only)
• Linezolid (IV and oral)
• Daptomycin

Question 2

How do they work?

Answer 2

• Quinopristin/dalfopristin & Linezolid work in the ribosome to stop protein synthesis
• Daptomycin has the long tail that gets into the cell membrane to make a pore that leaks K+ out.

Question 3

How are they excreted?

Answer 3

• Quinopritisn/dalfopristin: Nonrenal

- Linezolid & Daptomycin = Renal

Question 4

What does Quinopristin/dalfopristin kill?

Answer 4

Gram-positive cocci, including S. pneumoniae, beta- and alpha-hemolytic strains of streptococci, E. faecium (not E. faecalis), and coagulase-positive and coagulase-negative strains of staphylococci

Question 5

What does Linezolid kill?

Answer 5

Gram-positive organisms including staphylococci, streptococci, enterococci, gram-positive anaerobic cocci, and gram-positive rods such as Corynebacterium spp. and Listeria monocytogenes

Question 6

What does Daptomycin kill?

Answer 6

Aerobic, facultative, and anaerobic gram-positive bacteria

Question 7

What is Linezolid used for?

Answer 7

Vancomycin-resistant Enterococcus faecium infections, nosocomial pneumonia caused by Staphylococcus aureus (including MRSA) or Streptococcus pneumoniae (including multidrug-resistant strains), complicated and uncomplicated skin and skin structure infections (including diabetic foot infections without concomitant osteomyelitis), and community-acquired pneumonia caused by susceptible gram-positive organisms

Question 8

What is Daptomycin used for?

Answer 8

Treatment of complicated skin and skin structure infections caused by susceptible aerobic gram-positive organisms; Staphylococcus aureus bacteremia, including right-sided native valve infective endocarditis caused by MSSA or MRSA

Question 9

What is Quinopristin/dalfopristin used for?

Answer 9

Susceptible aerobic gram-positive organisms; Staphylococcus aureus bacteremia, including right-sided native valve infective endocarditis caused by MSSA or MRSA

Question 10

What are the types of Resistance?

Answer 10

• Quinupristin/dalfopristin
  - Differs per molecule and can change effect to bacteriostatic
  - Enzymes, efflux pumps etc.
• Linezolid
  - Mutation of 23S rRNA
• Daptomycin
  - Seen with deep-seated infections
  - May relate to cell membrane charge alterations

Question 11

What are the side effects for Quinopristin/dalfopristin?

Answer 11

• Adverse drug reactions
  - Arthalgias
  - Local injection site reactions
  - Hyperbilrubinemia
• Drug interactions
  - Possible (low) inhibition of CYP3A4

Question 12

What are the side effects for Daptomycin?

Answer 12

Adverse drug reactions

  - Allergic pneumonitis
   - Myopathy

Question 13

What are the side effects for Linezolid ?

Answer 13

• Adverse drug reactions
  - Hematologic
  - Other (Lactic acidosis, peripheral neuropathy)
• Drug interactions
  - SSRIs and serotonin syndrome

Question 14

Prescription for Synercid™ (Quinopristin/dalfopristin)?

Answer 14

7.5 mg/kg
every 12 hours for at least 7 days

Not used much

Question 15

Prescription for ***Zyvox™ (Linezolid )?

Answer 15

600 mg
every 12 hours for 10 to 14 days

IV or oral

Question 16

Prescription for Cubicin™ (Daptomycin)?

Answer 16

4 mg/kg IVPB
once daily for 7 to 14 days

For complicated infection, MRSA
Endocarditis: 8-10 mg/kg

Watch for renal effects! ( < 30 mL/min)