linezolid

Linezolid belongs to a new class of antibiotics known as oxazolidinones. Linezolid is used to treat serious bacterial infections of skin and soft tissue and pneumonia that are resistant to other antibiotics including methicillin and vancomycin. Linezolid is effective against a large spectrum of gram-positive bacteria. Gram-positive bacteria and gram-negative bacteria are structurally different, identified by whether they get dyed or not in the Gram stain lab test.

Linezolid inhibits bacterial growth by binding to the bacterial ribosomes (cellular particles that synthesize proteins) and blocks protein synthesis that enables bacterial growth. Linezolid is ineffective against viral infections.

Linezolid also belongs to a class of drugs known as monoamine oxidase (MAO) inhibitors which block the activity of monoamine oxidases, a family of enzymes in the body. MAO inhibition results in increased concentrations of chemicals that nerves use to communicate (neurotransmitters), including dopamine, norepinephrine, and serotonin, which can increase the chance of certain side effects and food and drug interactions.

Linezolid is used to treat the following bacterial infections:

Adult

• Vancomycin-resistant enterococcal infections
• Skin and skin structure infections (complicated and uncomplicated)
• Community-acquired pneumonia (including concurrent bacteremia)
• Nosocomial pneumonia (hospital-acquired pneumonia)
• Methicillin-resistant staphylococcal infections (MRSA)
• Methicillin-susceptible Staphylococcus aureus infection (MSSA)

Pediatric

• Pneumonia
• Vancomycin-resistant enterococcal infections
• Skin and skin structure infections (complicated and uncomplicated)

Linezolid is effective against most strains of the following organisms: Enterococcus faecalis, Enterococcus faecium, Pasteurella multocida, methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA), Staphylococcus epidermidis, Staphylococcus haemolyticus, Streptococcus agalactiae (group B streptococci), Streptococcus pneumonia, Streptococcus pyogenes (group A beta-hemolytic streptococci), and viridians group streptococci (S. mutans, S. salivarius, S. anginosus, S. mitis, S. sanguinis, and S. bovis)

• Do not take linezolid if you are allergic to the linezolid or any ingredients in it
• Do not take within 14 days of taking a MAO inhibitor
• Avoid tyramine-containing foods (aged cheese, cured or smoked meats, draft beer, fava beans, and soy products) and serotonergic drugs, as these may precipitate a hypertensive crisis
• Use with caution in patients with pheochromocytoma, uncontrolled hypertension, thyrotoxicosis, carcinoid syndrome, diabetes mellitus, or seizure disorders
• Use with caution in case of concurrent use with serotonergic or adrenergic drugs
• Use oral suspension with caution in phenylketonuria (contains phenylalanine)
• Do not use for gram-negative bacteria or for catheter-related infections; clinical studies showed a higher mortality rate with linezolid than with other antibiotics for these conditions
• Monitor for myelosuppression, consider discontinuation in patients who develop or have worsening myelosuppression
• Evaluate for Clostridium difficile if diarrhea occurs
• Peripheral and optic neuropathy were reported, especially in patients given extended courses of therapy exceeding 28 days
• May cause low blood sugar (hypoglycemia); monitor blood glucose levels
• Lactic acidosis reported with use; immediately evaluate patients who develop recurrent unexplained acidosis with nausea and vomiting
• Superinfection may develop

Common side effects of linezolid include:

Pediatric

• Diarrhea and loose stools
• Nausea
• Vomiting
• Headache
• Abdominal pain
• Vertigo
• Low red blood cell count (anemia)
• Low blood platelet count (thrombocytopenia)
• Increase in eosinophils, white blood cells (eosinophilia)
• Itching, other than application site

Adult

• Headache
• Diarrhea
• Nausea
• Vomiting
• Dizziness
• Rash
• Vaginal yeast infection (moniliasis)
• Fungal infection
• Taste alteration
• Oral thrush
• Abnormal liver function tests
• Abnormal blood tests
• Generalized abdominal pain
• Tongue discoloration
• Lactic acid buildup in blood (lactic acidosis)
• Bone marrow suppression (myelosuppression)
• Peripheral nerve damage (neuropathy)
• Numbness and tingling in arms and legs
• Damage to the optic nerve (optic neuropathy)
• Serotonin syndrome (high body temperature, agitation, increased reflexes, shakiness, sweating, dilated pupils, and diarrhea)
• Superficial tooth discoloration
• Superficial tongue discoloration
• Blood disorders due to myelosuppression including:
  • Low blood platelet count (thrombocytopenia)
  • Low white blood cell count (leukopenia)
  • Reduced white, red, and platelet blood cell count (pancytopenia)
  • Deficiency in normal blood red cells (sideroblastic anemia)
• Convulsions (seizures)
• Severe allergic reaction (anaphylaxis)
• Swelling in the tissue under the skin or mucous membranes (angioedema)
• Blood vessel inflammation (vasculitis) due to hypersensitivity
• Blistering (bullous) skin disorders including toxic epidermal necrolysis and Stevens-Johnson syndrome
• Low blood glucose (hypoglycemia)
• Low sodium (hyponatremia) and/or syndrome of inappropriate antidiuretic hormone secretion (SIADH)

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Injectable solution

• 2 mg/ml (100 ml, 300 ml infusion bags)

Oral suspension

• 100 mg/ml

Tablet

• 600 mg

Adult

Vancomycin-Resistant Enterococcal Infections

• 600 mg orally/intravenously every 12 hours for 14-28 days

Complicated Skin and Skin Structure Infections

• 600 mg orally/intravenously every 12 hours for 10-14 days

Uncomplicated Skin and Skin Structure Infections

• 400-600 mg orally every 12 hours for 10-14 days

Community-Acquired Pneumonia (Including Concurrent Bacteremia)

• 600 mg orally/intravenously every 12 hours for 10-14 days

Nosocomial Pneumonia

• 600 mg orally/intravenously every 12 hours for 10-14 days

Methicillin-Resistant Staphylococcal Infections

• 600 mg orally/intravenously every 12 hours

Methicillin-Susceptible Staphylococcus aureus

• 600 mg orally/intravenously every 12 hours for 10-14 days

Dosing Considerations

• Monitor CBC count each week

Pediatric

Vancomycin-Resistant Enterococcal Infections

• Children under 12 years old: 10 mg/kg orally/intravenously every 8 hours for 14-28 days
• Children 12 years and older: 600 mg orally/intravenously every 12 hours for 14-28 days

Complicated Skin and Skin Structure Infections

• Children under 12 years old: 10 mg/kg orally/intravenously every 8 hours for 10-14 days
• Children 12 years and older: 600 mg orally/intravenously every 12 hours for 10-14 days

Uncomplicated Skin and Skin Structure Infections

• Children under 5 years old: 10 mg/kg orally every 8 hours for 10-14 days
• Children 5-12 years old: 10 mg/kg orally every 12 hours for 10-14 days
• Children 12 years and older: 600 mg orally every 12 hours for 10-14 days

Pneumonia

• Children under 12 years old: 10 mg/kg orally/intravenously every 8 hours for 10-14 days
• Children 12 years and older: 600 mg orally/intravenously every 12 hours for 10-14 days

Dosing Considerations

Monitor CBC count each week

There is no known antidote for linezolid, but toxicity is rare. In case of overdose, symptomatic and supportive treatment is recommended with maintenance of kidney function (glomerular filtration). Hemodialysis may help rapidly eliminate linezolid.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Linezolid has severe interactions with at least 48 different drugs.
• Linezolid has serious interactions with at least 112 different drugs.
• Linezolid has moderate interactions with at least 43 different drugs.
• Linezolid has mild interactions with at least 23 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• Use linezolid during pregnancy with caution if benefits outweigh risks.
• There is no information on the effects of linezolid in breast milk production.
• Linezolid is present in breast milk. Safety of linezolid when breastfeeding is unknown; consult your physician.
• There is no information on effects of linezolid on breastfed infant, however, clinical trials report diarrhea and vomiting as the most common symptoms in infants treated with linezolid. Lactating mothers must monitor breastfed infant for these symptoms, if taking linezolid.

Serotonin syndrome

• Avoid administering linezolid to patients taking psychiatric drugs (SSRIs, SNRIs, TCAs, and MAOIs) except to treat life-threatening infections due to increased risk of serotonin syndrome.

Hyponatremia

• Linezolid can cause hyponatremia and/or syndrome of inappropriate antidiuretic hormone secretion (SIADH), the symptoms of which include confusion, somnolence, generalized weakness, and in severe cases, respiratory failure and even death.
• If signs and symptoms of hyponatremia and/or SIADH occur, discontinue therapy and institute appropriate supportive measures.