Linezolid

12.1 Mechanism of Action Linezolid is an antibacterial drug [see Microbiology ( 12.4 )] .

1 INDICATIONS AND USAGE Linezolid for Oral Suspension is an oxazolidinone-class antibacterial indicated in adults and children for the treatment of the following infections caused by susceptible Gram-positive bacteria: Nosocomial pneumonia ( 1.1 ); Community-acquired pneumonia ( 1. 2); Complicated skin and skin structure infections, including diabetic foot infections, without concomitant osteomyelitis ( 1. 3); Uncomplicated skin and skin structure infections ( 1. 4); Vancomycin-resistant Enterococcus faecium infections. ( 1. 5) Limitations of Use ( 1.6 ): • Linezolid is not indicated for the treatment of Gram-negative infections. • The safety and efficacy of linezolid formulations given for longer than 28 days have not been evaluated in controlled clinical trials. To reduce the development of drug-resistant bacteria and maintain the effectiveness of linezolid formulations and other antibacterial drugs, linezolid should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. ( 1.7 ) 1.1 Nosocomial Pneumonia Linezolid is indicated for the treatment of nosocomial pneumonia caused by Staphylococcus aureus (methicillin-susceptible and -resistant isolates) or Streptococcus pneumoniae [see Clinical Studies ( 14 )]. 1.2 Community-acquired Pneumonia Linezolid is indicated for the treatment of community-acquired pneumonia caused by Streptococcus pneumoniae , including cases with concurrent bacteremia, or Staphylococcus aureus (methicillin-susceptible isolates only) [see Clinical Studies ( 14 )]. 1.3 Complicated Skin and Skin Structure Infections Linezolid is indicated for the treatment of complicated skin and skin structure infections, including diabetic foot infections, without concomitant osteomyelitis, caused by Staphylococcus aureus (methicillin-susceptible and -resistant isolates), Streptococcus pyogenes , or Streptococcus agalactiae . Linezolid has not been studied in the treatment of decubitus ulcers [see Clinical Stu

2 DOSAGE AND ADMINISTRATION Dosage, Route, and Frequency of Administration Infection Pediatric Patients (Birth through 11 years of age) Adults and Adolescents (12 years and older) Duration (Days) Nosocomial pneumonia Community-acquired pneumonia, including concurrent bacteremia 10 mg/kg intravenous or oral every 8 hours 600 mg intravenous or oral every 12 hours 10 to 14 Complicated skin and skin structure infections Vancomycin-resistant Enterococcus faecium infections, including concurrent bacteremia 10 mg/kg intravenous or oral every 8 hours 600 mg intravenous or oral every 12 hours 14 to 28 Uncomplicated skin and skin structure infections less than 5 yrs: 10 mg/kg oral every 8 hours 5 to 11 yrs: 10 mg/kg oral every 12 hours Adults: 400 mg oral every 12 hours Adolescents: 600 mg oral every 12 hours 10 to 14 2.1 General Dosage and Administration The recommended dosage for linezolid formulations for the treatment of infections is described in Table 1. Table 1. Dosage Guidelines for Linezolid Infection Due to the designated pathogens [see Indications and Usage ( 1 )]. Dosage, Route, and Frequency of Administration Recommended Duration of Treatment (Consecutive Days) Pediatric Patients Neonates less than 7 days: Most pre-term neonates less than 7 days of age (gestational age less than 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 every 8 hours regimen in neonates with a sub-optimal clinical response. All neonatal patients should receive 10 mg/kg every 8 hours by 7 days of life [see Use in Specific Populations ( 8.4 ) and Clinical Pharmacology ( 12.3 )]. (Birth through 11 Years of Age) Adults and Adolescents (12 Years and Older) Nosocomial pneumonia 10 mg/kg intravenously or oral Oral dosing using either linezolid tablets or Linezolid for Oral Suspension [see How Supplied/Storage and Handling ( 16 )]. every 8 hours 600 mg intravenously or oral every 12 hours 10 to 14 Community-acquired pneumonia, including concurrent bacteremia Complicated skin and skin structure infections Vancomycin-resistant Enterococcus faecium infections, including concurrent bacteremia 10 mg/kg intravenously or oral every 8 hours 600 mg intravenously or oral every 12 hours 14 to 28 Uncomplicated skin and skin structure infections Less than 5 yrs: 10 mg/kg oral every 8 hours 5 to 11 yrs: 10 mg/kg oral every 12 hours Adults: 400 mg oral every 12 hours Adolescents: 600 mg oral every 12 hours 10 to 14 No dose adjustment is necessary when switching from intravenous to oral administration. 2.5 Constitution of Oral Suspension Linezolid for Oral Suspension is supplied as a powder for constitution. Gently tap bottle to loosen powder. Add a total of 123 mL distilled water in two portions. After adding the first half, shake vigorously to wet all of the powder. Then add the second half of the water and shake vigorously to obtain a uniform suspension. After constitution, each 5 mL of the suspension contains 100 mg of linezolid. Before using, gently mix by inverting the bottle 3 to 5 times. Do not shake . Store constituted suspension at room temperature. Use within 21 days after constitution.

6 ADVERSE REACTIONS Most common adverse reactions (>5% of adult and/or pediatric patients treated with linezolid) include: diarrhea, vomiting, headache, nausea, and anemia. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-800-962-8364 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The following clinically significant adverse reactions are described elsewhere in the labeling: Myelosuppression [see Warnings and Precautions ()] Peripheral and Optic Neuropathy [see Warnings and Precautions ()] Serotonin Syndrome [see Warnings and Precautions ()] Clostridioides difficile -Associated Diarrhea [see Warnings and Precautions ()] Lactic Acidosis [see Warnings and Precautions ()] Convulsions [see Warnings and Precautions ()] Rhabdomyolysis [see Warnings and Precautions ()] Hypoglycemia [see Warnings and Precautions ()] Hyponatremia and/or Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) [see Warnings and Precautions ()] 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adults : The safety of linezolid formulations was evaluated in 2,046 adult patients enrolled in seven Phase 3 comparator-controlled clinical trials, who were treated for up to 28 days. Of the patients treated for uncomplicated skin and skin structure infections (uSSSIs), 25.4% of linezolid-treated and 19.6% of comparator-treated patients experienced at least one drug-related adverse event. For all other indications, 20.4% of linezolid-treated and 14.3% of comparator-treated patients experienced at least one drug-related adverse event. Table 2 shows the incidence of all-causality, treatment-emergent adverse reactions reported in at least 1% of adult patients in these trials by dose of linezolid. Table 2. Incidence (%) of Treatment-Emergent Adverse Reactions Occurring in >1% of Adult Patients Treated with Linezolid in Comparator-Controlled Clinical Trials Uncomplicated Skin and Skin Structure Infections All Other Indications ADVERSE REACTIONS Linezolid 400 mg by mouth every 12 hours (n=548) Clarithromycin 250 mg by mouth every 12 hours (n=537) Linezolid 600 mg every 12 hours (n=1498) All Other Comparators Comparators included cefpodoxime proxetil 200 mg by mouth every 12 hours; ceftriaxone 1 g intravenously every 12 hours; dicloxacillin 500 mg by mouth every 6 hours; oxacillin 2 g intravenously every 6 hours; vancomycin 1 g intravenously every 12 hours. (n=1464) Headache 8.8 8.4 5.7 4.4 Diarrhea 8.2 6.1 8.3 6.4 Nausea 5.1 4.5 6.6 4.6 Vomiting 2.0 1.5 4.3 2.3 Dizziness 2.6 3.0 1.8 1.5 Rash 1.1 1.1 2.3 2.6 Anemia 0.4 0 2.1 1.4 Taste alteration 1.8 2.0 1.0 0.3 Vaginal moniliasis 1.8 1.3 1.1 0.5 Oral moniliasis 0.5 0 1.7 1.0 Abnormal liver function tests 0.4 0.2 1.6 0.8 Fungal infection 1.5 0.2 0.3 0.2 Tongue discoloration 1.3 0 0.3 0 Localized abdominal pain 1.3 0.6 1.2 0.8 Generalized abdominal pain 0.9 0.4 1.2 1.0 Of the patients treated for uSSSIs, 3.5% of linezolid-treated and 2.4% of comparator-treated patients discontinued treatment due to drug-related adverse events. For all other indications, discontinuations due to drug-related adverse events occurred in 2.1% of linezolid-treated and 1.7% of comparator-treated patients. The most common reported drug-related adverse events leading to discontinuation of treatment were nausea, headache, diarrhea, and vomiting. Pediatric Patients : The safety of linezolid formulations was evaluated in 215 pediatric patients ranging in age from birth through 11 years, and in 248 pediatric patients aged 5 through 17 years (146 of these 248 were age 5 through 11 and 102 were age 12 to 17). These patients were enrolled in two Phase 3 comparator-controlled clinical trials and were treated for up to 28 days. In the study of hospitalized pediatric patients (birth through 11 years) with Gram-positive infections, who were randomized 2 to 1 (linezolid: vancomycin), mortality was 6% (13/215) in the linezolid arm and 3% (3/101) in the vancomycin arm. However, given the severe underlying illness in the patient population, no causality could be established. Of the pediatric patients treated for uSSSIs, 19.2% of linezolid-treated and 14.1% of comparator-treated patients experienced at least one drug-related adverse event. For all other indications, 18.8% of linezolid-treated and 34.3% of comparator-treated patients experienced at least one drug-related adverse event. Table 3 shows the incidence of all-causality, treatment-emergent adverse reactions reported in more than 1% of pediatric patients (and more than 1 patient) in either treatment group in the comparator-controlled Phase 3 trials. Table 3. Incidence (%) of Treatment-Emergent Adverse Reactions Occurring in >1% of Pediatric Patients (and >1 Patient) in Either Treatment Group in C

7 DRUG INTERACTIONS Monoamine oxidase inhibitors and potential for interaction with adrenergic and serotonergic agents. ( 4.2 , 5.3 , 5.6 , 7 , 12.3 ) 7.1 Monoamine Oxidase Inhibitors Linezolid is a reversible, nonselective inhibitor of monoamine oxidase [see Contraindications ( 4.2 ) and Clinical Pharmacology ( 12.3 )]. 7.2 Adrenergic and Serotonergic Agents Linezolid has the potential for interaction with adrenergic and serotonergic agents [see Warnings and Precautions ( 5.3 , 5.6 ) and Clinical Pharmacology ( 12.3 )] .