Linzolid 600 IV Infusion

Indication
Vancomycin-Resistant Enterococcus faecium infections including cases with concurrent bacteremia.Nosocomial pneumonia caused by Staphylococcus aureus (methicillin-susceptible and -resistant strains) or Streptococcus pneumoniae (including multi-drug resistant strains). Combination therapy may be clinically indicated if the documented or presumptive pathogens include Gram-negative organism.Complicated skin and skin structure infections, including diabetic foot infections (without concomitant osteomyelitis) caused by Staphylococcus aureus (methicillin-susceptible and resistant strains), Streptococcus pyogenes, or Streptococcus agalactiae.Uncomplicated skin and skin structure infections caused by Staphylococcus aureus (methicillin-susceptible only) or Streptococcus pyogenes.Community-acquired pneumonia caused by Streptococcus pneumoniae (including multi-drug resistant strains) including cases with concurrent bacteremia, or Staphylococcus aureus (methicillin-susceptible strains only)

Pharmacology
Linezolid?ÿis a synthetic, antibacterial agent belonging to a new class of antibiotics, the oxazolidinones, with in vitro activity against Gram positive aerobic bacteria, some Gram positive anaerobic bacteria and certain Gram negative bacteria. It selectively inhibits bacterial protein synthesis via a mechanism of action different from that of other antibacterial agents. Linezolid binds to the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome and prevents the formation of a functional 70S initiation complex which is an essential component of the bacterial translation process. The results of time-kill studies have shown Linezolid to be bacteriostatic against enterococci and staphylococci. For streptococci, Linezolid was found to be bactericidal for the majority of strains.

Dosage
Patients who commence treatment on the parenteral formulation may be switched to either oral presentation when clinically indicated. In such circumstances, no dose adjustment is required as Linezolid has an oral bioavailability of approximately 100%. The injection should be administered over a period of 30 to 120 minutes. The film coated tablets or oral suspension may be taken with or without food.Adults and Adolescents (12 Years and Older): Complicated skin and skin structure infections & Community-acquired pneumonia, including concurrent bacteremia: 600 mg IV or oral b.i.d. for 10 to 14 days. Vancomycin-resistant Enterococcus faecium infections, including concurrent bacteremia: 600 mg IV or oral b.i.d. for 14-28?ÿ For Pediatric Patients (Birth through 11 Years of Age): Complicated skin and skin structure infections & Community-acquired pneumonia, including concurrent bacteremia: 600 mg IV or oral b.i.d. for 10 to 14 days. Vancomycin-resistant Enterococcus faecium infections, including concurrent bacteremia: 600 mg IV or oral b.i.d.for 14-28. Neonates <7 days: Most pre-term neonates <7 days of age (gestational age <34 weeks) have lower systemic linezolid clearance values and larger AUC values than many full-term neonates and older infants. These neonates should be initiated with a dosing regimen of 10 mg/kg every 12 hours. Consideration may be given to the use of 10 mg/kg in every eight hours regimen in neonates with a sub-optimal clinical response. All neonatal patients should receive 10 mg/kg t.i.d. by 7 days of life.

Interaction
Monoamine Oxidase Inhibition: Linezolid is a reversible, nonselective inhibitor of monoamine oxidase. Therefore, Linezolid has the potential for interaction with adrenergic and serotonergic agents.Adrenergic Agents: Some individuals receiving Linezolid may experience a reversible enhancement of the pressor response to indirect-acting sympathomimetic agents, vasopressor or dopaminergic agents. Initial doses of adrenergic agents, such as dopamine or epinephrine, should be reduced and titrated to achieve the desired response.?ÿSerotonergic Agents: Physicians should be alert to the possible signs and symptoms of serotonergic syndrome in patients receiving concomitant Linezolid and serotonergic agents.

Contradiction
Linezolid formulations are contraindicated for use in patients who have known hypersensitivity to Linezolid or any of the other product components. Linezolid should not be used in patients taking any medicinal product which inhibits monoamine oxidases A or B (e.g. phenelzine, isocarboxazid) or within two weeks of taking any such medicinal product. Linezolid should not be administered to patients with uncontrolled hypertension, pheochromocytoma, thyrotoxicosis, carcinoid syndrome and/or patients taking directly and indirectly acting sympathomimetic agents (e.g. pseudoephedrine), vasopressive agents (e.g. epinephrine, norepinephrine), dopaminergic agents (e.g. dopamine, dobutamine), serotonin re-uptake inhibitors, tricyclic antidepressants, serotonin 5-HT1 receptor agonists (triptans), meperidine or buspirone.

Side Effect
Most of the adverse events reported with Linezolid were mild to moderate in intensity. The most common adverse events in patients treated with Linezolid were diarrhea, headache and nausea. Other adverse included oral moniliasis, vaginal moniliasis, hypertension, dyspepsia, localized abdominal pain, pruritus, and tongue discoloration.

Pregnancy
Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. Linezolid should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether Linezolid is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Linezolid is administered to a nursing woman.

Precaution
Patients who develop recurrent nausea or vomiting, unexplained acidosis, or low bicarbonate level while receiving Linezolid should receive immediate medical evaluation. Where administration of Linezolid and concomitant serotonergic agents is clinically appropriate, patients should be closely observed for signs and symptoms of serotonin syndrome such as cognitive dysfunction, hyperpyrexia, hyper reflexia and incoordination. If signs or symptoms occur physicians should consider discontinuation of either one or both agents. If the concomitant serotonergic agent is withdrawn, discontinuation symptoms can be observed. If patients experience symptoms of visual impairment, such as changes in visual acuity, changes in color vision, blurred vision, or visual field defect, prompt ophthalmic evaluation is recommended. Convulsions have been reported in patients when treated with Linezolid. In some of these cases, a history of seizures or risk factors for seizures was reported.

Overdose
No cases of overdose have been reported. Symptomatic and supportive care is advised together with maintenance of glomerular filtration. Approximately 30% of a Linezolid dose is removed during 3 hours of haemodialysis. No data are available for the removal of Linezolid by peritoneal dialysis or haemoperfusion.

Storage
Should be stored at room temperature 25?ø C, away from light and moisture.