Linezolid Flashcards

Questions and Answers

What is the mechanism of action (MOA) of linezolid?

Inhibits bacterial cell wall synthesis

Inhibits bacterial RNA synthesis

Inhibits bacterial protein synthesis (correct)

Inhibits bacterial DNA replication

What percentage of linezolid is excreted unchanged in urine?

30%

Which of the following organisms are treated by linezolid? (Select all that apply)

Staphylococcus aureus (including MRSA) (correct)

Streptococcus pneumoniae

Enterococcus faecium (including VRE) (correct)

Escherichia coli

One major setback of linezolid is ___.

cost Signup and view all the answers

Linezolid is associated with thrombocytopenia.

True Signup and view all the answers

What is the recommended dosage of linezolid for treating an infection?

600 mg q 12 hours IV or PO Signup and view all the answers

Match the following side effects with linezolid:

Thrombocytopenia = Blood disorder Diarrhea = Gastrointestinal issue Hypertension = Blood pressure elevation Nausea = Gastrointestinal issue Signup and view all the answers

Study Notes

Mechanism of Action (MOA)

Linezolid is an oxazolidinone antibiotic.
It inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit.
This binding prevents the formation of the 70S initiation complex, differentiating its MOA from other antibiotics.

Elimination

Non-renal clearance accounts for approximately 65% of linezolid elimination.
30% of the drug is excreted unchanged in urine.
40% is eliminated as metabolite B, and 10% as metabolite A.
Low renal clearance suggests net tubular reabsorption of the drug.

Spectrum of Activity

Effective against Enterococcus faecium, including vancomycin-resistant strains (VRE).
Active against Staphylococcus aureus, including MRSA.
Also targets Enterococcus faecalis, coagulase-negative staphylococci, and various Streptococcus species.

Adverse Effects (AE)

Thrombocytopenia is a significant side effect.
Monoamine oxidase inhibition can lead to serotonin syndrome, presenting as hypertension, fever, confusion, and can be fatal.
Other adverse effects include diarrhea, headache, and nausea.

Dosage

Standard dosage is 600 mg administered every 12 hours, either intravenously (IV) or orally (PO).
For uncomplicated skin infections, a reduced dosage of 400 mg every 12 hours is recommended.

Treatment Indications

Linezolid treats skin infections, MRSA pneumonia, and VRE-related urinary tract infections (UTIs) and bacteremia.

Cost Implications

A major disadvantage of linezolid is its high cost, which can limit access and utilization in clinical settings.

Description

Test your knowledge of linezolid with these informative flashcards. This quiz covers key concepts such as its mechanism of action and elimination pathways. Perfect for students in pharmacology or medicine.