Antibiotic Linezolid (Zyvox)

• Generic name: Linezolid
• Brand/Trade names: Zyvox
• Dosages:
  Tablets 400 mg, 600 mg;
  Powder for oral suspension 100 mg per 5 mL;
  Injection 2 mg/mL
• Pharmacologic category: Oxazolidinone antibiotic
• FDA approved: April 18, 2000
• Habit forming? No
• Pregnancy risk factor: C

Linezolid (Zyvox) is a member of a new class of antibiotics called oxazolidinones with a unique mechanism of action. It is used to treat certain types of pneumonia, complicated and uncomplicated skin and skin structure infections, and vancomycin-resistant Enterococcus faecium infections.

This antibacterial medication is not indicated for the treatment of gram-negative infections.

The most frequently reported side effects with Linezolid (Zyvox) treatment are headache, nausea, diarrhea, and vomiting. The most important laboratory test change is a decrease in platelet counts.

• Absorption: rapid and complete absorption from gastrointestinal tract.
• Metabolism: Partial hepatic metabolism, metabolized in the liver, by oxidation of the morpholine ring, without involvement of the cytochrome P450 system.
• Elimination half-life: Children 1 week to 11 years: 1.5-3 hours; Adults: 4-5 hours.
• Excretion: Elimination occurs through nonrenal (65%), renal (30%), and fecal (5%) mechanisms.

• High cure rates for various types of infections.
• Effective and promising new antibacterial drug for the treatment of several serious antibiotic-resistant infections, including difficult-to-treat organisms MRSA and VRE.
• When used for short periods, linezolid is a relatively safe.
• Linezolid does not damage kidney or liver function.
• Linezolid is virtually 100% absorbed if taken by mouth, so oral dosing is essentially equivalent to parenteral dosing. Excellent bioavailability allows early change from intravenous to oral drug therapy.
• Minimal potential for resistance. Cross-resistance does not develop between linezolid and other antibacterial agents.

• Linezolid (Zyvox) is new and quite expensive antibiotic.
• Risk of hematological disturbances, including anemia, thrombocytopenia, and myelosuppression. Linezolid can cause bone marrow suppression and low platelet counts, particularly when used for more than two weeks. Thrombocytopenia (low platelet count), uncommon with short-term use for 14 days or fewer, but occurs much more frequently in patients who receive longer courses or who have renal impairment.
• Prolonged use of linezolid may cause damage to the peripheral nervous system (peripheral neuropathy) and optic nerve (optic neuropathy)2.
• Lactic acidosis, a potentially life-threatening buildup of lactic acid in the body, is rare but serious side effect that may occur with linezolid due to its mitochondrial toxicity.
• Potential for drug-drug interactions. Linezolid (Zyvox) is a weak MAO inhibitor (nonselective).

• Infective endocarditis
• Bone and joint infections
• Central nervous system infections (including meningitis)
• Extensively drug-resistant tuberculosis1

Linezolid stops the growth of bacteria by disrupting their production of proteins. Although many antibiotics work this way, the exact mechanism of action of linezolid appears to be unique to the oxazolidinone class. Linezolid works on the first step of protein synthesis, initiation, unlike most other protein synthesis inhibitors, which inhibit elongation.

Bacterial resistance to linezolid has remained very low since it was first detected in 1999, although it may be increasing.

• User Reviews for Zyvox (Linezolid) on Drugs.com

• 1. Park IN, Hong SB, Oh YM, Kim MN, Lim CM, Lee SD, Koh Y, Kim WS, Kim DS, Kim WD, Shim TS. Efficacy and tolerability of daily-half dose linezolid in patients with intractable multidrug-resistant tuberculosis. J Antimicrob Chemother. 2006 Sep;58(3):701-4.
• 2. Bressler AM, Zimmer SM, Gilmore JL, Somani J. Peripheral neuropathy associated with prolonged use of linezolid. Lancet Infect Dis. 2004 Aug;4
• 3. De Vriese AS, Coster RV, Smet J, Seneca S, Lovering A, Van Haute LL, Vanopdenbosch LJ, Martin JJ, Groote CC, Vandecasteele S, Boelaert JR. Linezolid-induced inhibition of mitochondrial protein synthesis. Clin Infect Dis. 2006 Apr 15;42(8):1111-7.

Last modified: April, 2010