Linezolid

RECENT MAJOR CHANGES Warnings and Precautions, Myelosuppression (5.1) 7/2023 Warnings and Precautions, Rhabdomyolysis (5.9) 6/2024

1 INDICATIONS AND USAGE Linezolid 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 Studies ( 14 ) ]. 1.4 Uncomplicated Skin and Skin Structure Infections Linezolid is indicated for the treatment of uncomplicated skin and skin structure infections caused by Staphylococcus aureus (methicillin-susceptible isolates only) or Streptococcus pyogenes [ see Clinical Studies ( 14 ) ]. 1.5 Vancomycin-resistant Enterococcus faecium Infections Linezolid is indicated for the treatment of vancomycin-resistant Enterococcus faecium infections, including cases with concurrent bacteremia [ see Clinical Studies ( 14 ) ]. 1.6 Limitations of Use Linezolid is not indicated for the treatment of Gram-negative infections. It is critical that specific Gram-negative therapy be initiated immediately if a concomitant Gram-negative pathogen is documented or suspected [ see Warnings and Precautions ( 5.4 ) ]. The safety and efficacy of Linezolid formulations given for longer than 28 days have not been evaluated in controlled clinical trials [ see Clinical Studies ( 14 ) ]. 1.7 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of linezolid injection and other antibacterial drugs, linezolid injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. 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 Clinica …

2 DOSAGE AND ADMINISTRATION Dosage, Route, and Frequency of Administration Infection Pediatric Patients Adults and Adolescents Duration (days ) Nosocomial pneumonia 10 mg/kg intravenous or oral every 8 hours 600 mg intravenous 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 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* Dosage and Route of Administration Recommended Duration of Treatment (consecutive days) Pediatric Patients † (Birth through 11 Years of Age) Adults and Adolescents (12 Years and Older) Nosocomial pneumonia 10 mg/kg intravenously or oral ‡ 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 * Due to the designated pathogens [ see Indications and Usage ( 1 ) ]. † 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 ) ]. ‡ Oral dosing using either linezolid tablets or linezolid for oral suspension. No dose adjustment is necessary when switching from intravenous to oral administration. 2.2 Intravenous Administration Linezolid injection is supplied in single-use, ready-to-use flexible plastic containers. Parenteral drug products should be inspected visually for particulate matter prior to administration. Check for leakage by squeezing container firmly. If any leakage, discard solution as sterility may be impaired . Keep the infusion bag in the overwrap until ready to use. Store at room temperature. Protect from freezing. Linezolid injection may exhibit a yellow color that can intensify over time without adversely affecting potency. Linezolid injection should be administered by intravenous infusion over a period of 30 to 120 minutes. Do not use this intravenous flexible plastic container in series connections . Additives should not be introduced into this solution. If linezolid injection is to be given concomitantly with another drug, each drug should be given separately in accordance with the recommended dosage and route of administration for each product. If the same intravenous line is used for sequential infusion of several drugs, the line should be flushed before and after infusion of linezolid injection with an infusion solution compatible with linezolid injection and with any other drug(s) administered via this common line. 2.3 Compatibilities Compatible intravenous solutions include 0.9% Sodium Chloride Injection, 5% Dex …

3 DOSAGE FORMS AND STRENGTHS Linezolid intravenous injection: 200 mg/100 mL (2 mg/mL) and 600 mg/300 mL (2 mg/mL) linezolid single-dose, ready-to-use flexible plastic infusion bags in a foil laminate overwrap. • Injection: 200 mg/100 mL (2 mg/mL) and 600 mg/300 mL (2 mg/mL) linezolid. ( 3 )

4 CONTRAINDICATIONS Known hypersensitivity to linezolid or any of the other product components. (4.1); Patients taking any monoamine oxidase inhibitors (MAOI) or within two weeks of taking an MAOI. (4.2) 4.1 Hypersensitivity Linezolid is contraindicated for use in patients who have known hypersensitivity to linezolid or any of the other product components. 4.2 Monoamine Oxidase Inhibitors 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.

4.1 Hypersensitivity Linezolid is contraindicated for use in patients who have known hypersensitivity to linezolid or any of the other product components.

4.2 Monoamine Oxidase Inhibitors 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.

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 Fresenius Kabi USA, LLC, Vigilance & Medical Affairs at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 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 ADVERSE REACTIONS Uncomplicated Skin and Skin Structure Infections All Other Indications 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=1,498) All Other Comparators* (n=1,464) 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 1.5 4.3 2.3 Dizziness 2.6 3 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 1 0.3 Vaginal moniliasis 1.8 1.3 1.1 0.5 Oral moniliasis 0.5 0 1.7 1 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 * 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. 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 …

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 ) ].

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 ) ].

8 USE IN SPECIFIC POPULATIONS 8.1 Pregnancy Risk Summary Available data from published and postmarketing case reports with linezolid use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. When administered during organogenesis, linezolid did not cause malformations in mice, rats, or rabbits at maternal exposure levels approximately 6.5 times (mice), equivalent to (rats), or 0.06 times (rabbits) the clinical therapeutic exposure, based on AUCs. However, embryo-fetal lethality was observed in mice at 6.5 times the estimated human exposure. When female rats were dosed during organogenesis through lactation, postnatal survival of pups was decreased at doses approximately equivalent to the estimated human exposure based on AUCs ( see Data ). The background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data In mice, embryo-fetal toxicities were observed only at doses that caused maternal toxicity (clinical signs and reduced body weight gain). An oral dose of 450 mg/kg/day given from Gestation Day (GD) 6-16 (6.5 times the estimated human exposure based on AUCs) correlated with increased postimplantational embryo death, including total litter loss, decreased fetal body weights, and an increased incidence of costal cartilage fusion. Neither maternal nor embryo-fetal toxicities were observed at doses up to 150 mg/kg/day. Fetal malformations were not observed. In rats, fetal toxicity was observed at 15 and 50 mg/kg/day administered orally from GD 6-17 (exposures 0.22 times to approximately equivalent to the estimated human exposure, respectively, based on AUCs). The effects consisted of decreased fetal body weights and reduced ossification of sternebrae, a finding often seen in association with decreased fetal body weights. Fetal malformations were not observed. Maternal toxicity, in the form of reduced body weight gain, was seen at 50 mg/kg/day. In rabbits, reduced fetal body weight occurred only in the presence of maternal toxicity (clinical signs, reduced body weight gain and food consumption) when administered at an oral dose of 15 mg/kg/day given from GD 6-20 (0.06 times the estimated human exposure based on AUCs). Fetal malformations were not observed. When female rats were treated with 50 mg/kg/day (approximately equivalent to the estimated human exposure based on AUCs) of linezolid during pregnancy and lactation (GD 6 through Lactation Day 20), survival of pups was decreased on postnatal days 1 to 4. Male and female pups permitted to mature to reproductive age, when mated, showed an increase in preimplantation loss. 8.2 Lactation Risk Summary Linezolid is present in breast milk. Based on data from available published case reports, the daily dose of linezolid that the infant would receive from breast milk would be approximately 6% to 9% of the recommended therapeutic infant dose (10 mg/kg every 8 hours). There is no information on the effects of linezolid on the breastfed infant; however, diarrhea and vomiting were the most common adverse reactions reported in clinical trials in infants receiving linezolid therapeutically [ see Adverse Reactions ( 6.1 ) ] and (see Clinical Considerations). There is no information on the effects of linezolid on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for linezolid and any potential adverse effects on the breastfed child from linezolid or from the underlying maternal condition. Clinical Considerations Advise lactating women to monitor a breastfed infant for diarrhea and vomiting. 8.3 Females and Males of Reproductive P …

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

11 DESCRIPTION Linezolid injection contains linezolid, which is a synthetic antibacterial agent of the oxazolidinone class. Linezolid is a white to creamish crystalline powder. The chemical name for linezolid is (S)-N-[[3-[3-Fluoro-4-(4­-morpholinyl)phenyl]-2-oxo-5-oxazolidinyl] methyl]-acetamide. The molecular formula is C 16 H 20 FN 3 O 4 . Its molecular weight is 337.35, and its chemical structure is represented below: Linezolid injection is supplied as a ready-to-use sterile, clear colorless to slightly yellow color isotonic solution for intravenous infusion. Each mL contains 2 mg of linezolid. Inactive ingredients are dextrose monohydrate 50.24 mg/mL in an aqueous vehicle for intravenous administration, sodium citrate dihydrate 1.64 mg/mL, and citric acid monohydrate 0.85 mg/mL. Sodium hydroxide NF and/or hydrochloric acid NF are used to adjust the pH. The sodium (Na + ) content is 0.38 mg/mL (5 mEq/300 mL bag). Linezolid Chemical Structure

10 OVERDOSAGE In the event of overdosage, supportive care is advised, with maintenance of glomerular filtration. Hemodialysis may facilitate more rapid elimination of linezolid. In a Phase 1 clinical trial, approximately 30% of a dose of linezolid was removed during a 3-hour hemodialysis session beginning 3 hours after the dose of linezolid was administered. Data are not available for removal of linezolid with peritoneal dialysis or hemoperfusion. Clinical signs of acute toxicity in animals were decreased activity and ataxia in rats and vomiting and tremors in dogs treated with 3,000 mg/kg/day and 2,000 mg/kg/day, respectively.

16 HOW SUPPLIED/STORAGE AND HANDLING 16.1 Injection Linezolid injection is available in a single-use, ready-to-use flexible plastic container in a foil laminate overwrap. The flexible plastic container and port are latex-free. The flexible plastic container is available as follows: Product No . NDC No . Strength Size 713013 66298-7131-3 600 mg per 300 mL (2 mg per mL) 300 mL flexible plastic container. 16.2 Storage Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light. It is recommended that the infusion bags be kept in the overwrap until ready to use. Protect infusion bags from freezing. The container closure is not made with natural rubber latex. Non-PVC, Non-DEHP, Sterile.

16.1 Injection Linezolid injection is available in a single-use, ready-to-use flexible plastic container in a foil laminate overwrap. The flexible plastic container and port are latex-free. The flexible plastic container is available as follows: Product No . NDC No . Strength Size 713013 66298-7131-3 600 mg per 300 mL (2 mg per mL) 300 mL flexible plastic container.

16.2 Storage Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light. It is recommended that the infusion bags be kept in the overwrap until ready to use. Protect infusion bags from freezing. The container closure is not made with natural rubber latex. Non-PVC, Non-DEHP, Sterile.