Oxazolidinones

Question 1

Oxazolidinones

Answer 1

Linezolid
Tedizolid

Broad Gram+ activity and excellent oral bioavailability

Lin- twice daily
Ted- once daily
Differences between the two are minor

Lin has been out longer; has more clinical trial data supporting use for MRSA pneumonia

Question 2

Oxazolidinones MOA

Answer 2

Protein synthesis inhibitors (bind to 50S ribosomal subunit) blocking the formation of a stable 70S initiation complex and preventing translation
This binding site is distinct from other protein synthesis inhibitors

Question 3

Oxazolidinones Spectrum

Answer 3

Good
MSSA / MRSA
Strep (including multidrug resistant S. pneumo)
Enterococci (including VRE)
Nocardia

Moderate
Some atypicals
M. tuberculosis

Poor
All Gram-
Anaerobes

Question 4

Oxazolidinones Adverse Effects

Answer 4

Generally well tolerated
Can cause bone marrow suppression (most commonly thrombocytopenia); tends to occur after 2 or more weeks with Lin and needs monitoring; Ted seems to have same effect but longer duration studies are needed
Very prolonged therapy (months) with Lin can cause mitochondrial toxicity (peripheral neuropathy or lactic acidosis)

Question 5

Oxazolidinones Important Facts

Answer 5

Have bioavailability over 90%

Linez is MAO inhibitor
Can cause serotonin syndrome when given with serotonergic agents
This reaction is uncommon but does occur
Animal studies show Tediz has minimal MAO inhibition

Linez has dual elimination; do not need to adjust in renal or hepatic dysfunction
Tediz eliminated primarily by liver; may not sufficiently concentrate in urine to treat UTIs

Tediz was studied as 6 day therapy for skin infections; comparable to 10 days of linez

Oral formulations are less expensive and more convenient than home infusion Vanco and a nurse

Question 6

Oxazolidinones Good For

Answer 6

Infections caused by resistant Gram+ organisms like MRSA and VRE

Linez useful for pneumonia, skin/ss infections, UTIs, and other uses

Tediz currently indicated for skin/ss infections; may be useful for other types