Zyvox

Warnings and Precautions, Serotonin Syndrome ( 5.3 ) 6/2026

1 INDICATIONS AND USAGE ZYVOX 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 ): • ZYVOX is not indicated for the treatment of Gram-negative infections. • The safety and efficacy of ZYVOX 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 ZYVOX formulations and other antibacterial drugs, ZYVOX 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 ZYVOX 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 ZYVOX 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 ZYVOX 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 . ZYVOX has not been studied in the treatment of decubitus ulcers [ see Clinical Studies (14) ]. 1.4 Uncomplicated Skin and Skin Structure Infections ZYVOX 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 ZYVOX 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 • ZYVOX 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 ZYVOX 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 ZYVOX and other antibacterial drugs, ZYVOX 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.

2 DOSAGE AND ADMINISTRATION Dosage, Route, and Frequency of Administration Infection Pediatric Patients (Birth through11years of Age) Adults and Adolescents (12 years and Older) 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 5–11 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 ZYVOX formulations for the treatment of infections is described in Table 1. Table 1. Dosage Guidelines for ZYVOX Dosage, Route and Frequency of Administration Recommended Duration of Treatment (consecutive days) Infection Due to the designated pathogens [ see Indications and Usage (1)] 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 Community-acquired pneumonia, including concurrent bacteremia 10 mg/kg intravenously or oral Oral dosing using either ZYVOX Tablets or ZYVOX for Oral Suspension [ see How Supplied/Storage and Handling (16)]. every 8 hours 600 mg intravenously 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 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 5–11 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. 2.2 Intravenous Administration ZYVOX I.V. Injection is supplied in single-use, ready-to-use infusion bags. Parenteral drug products should be inspected visually for particulate matter prior to administration. Check for minute leaks by firmly squeezing the bag. If leaks are detected, discard the solution, as sterility may be impaired . Keep the infusion bags in the overwrap until ready to use. Each overwrap contains a peel-off label. Apply the peel-off label to the infusion bag for barcode scanning before use. Store at room temperature. Protect from freezing. ZYVOX I.V. Injection may exhibit a yellow color that can intensify over time without adversely affecting potency. ZYVOX I.V. Injection should be administered by intravenous infusion over a period of 30 to 120 minutes. Do not use this intravenous infusion bag in series connections . Additives should not be introduced into this solution. If ZYVOX I.V. 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 ZYVOX I.V. Injection with an infusion solution compatible with ZYVOX I.V. Injecti …

3 DOSAGE FORMS AND STRENGTHS ZYVOX I.V. Injection: 100-mL (200 mg linezolid) and 300-mL (600 mg linezolid) single-use, ready-to-use flexible plastic infusion bags in a foil laminate overwrap. The infusion bags and ports are latex-free. ZYVOX 600 mg Tablet: white, capsule-shaped, film-coated tablet printed with "ZYVOX 600 mg" white, capsule-shaped, film-coated tablet debossed with "ZYV" on one side and "600" on the other ZYVOX for Oral Suspension: dry, white to off-white, orange-flavored granule/powder. When constituted as directed, each bottle will contain 150 mL of a suspension providing the equivalent of 100 mg of linezolid per each 5 mL. Injection: 200 and 600 mg linezolid; Tablet: 600 mg linezolid; Oral Suspension: 100 mg of linezolid per each 5 mL. ( 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 ZYVOX formulations are 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 ZYVOX) include: diarrhea, vomiting, headache, nausea, and anemia. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc at 1-800-438-1985 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 ZYVOX formulations was evaluated in 2046 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 ZYVOX-treated and 19.6% of comparator-treated patients experienced at least one drug-related adverse event. For all other indications, 20.4% of ZYVOX -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 ZYVOX. Table 2. Incidence (%) of Treatment–Emergent Adverse Reactions Occurring in >1% of Adult Patients Treated with ZYVOX in Comparator-Controlled Clinical Trials ADVERSE REACTIONS Uncomplicated Skin and Skin Structure Infections All Other Indications ZYVOX 400 mg by mouth every 12 hours (n=548) Clarithromycin 250 mg by mouth every 12 hours (n=537) ZYVOX 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 ZYVOX-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 ZYVOX-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 ZYVOX 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 6.0% (13/215) in the linezolid arm and 3.0% (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 ZYVOX-treated and 14.1% of comparator-treated patients experienced at least one drug-related adverse event. For all other indications, 18.8% of ZYVOX-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 tha …

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) ].

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 breastmilk 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 Po …

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

11 DESCRIPTION ZYVOX I.V. Injection, ZYVOX Tablets, and ZYVOX for Oral Suspension contain linezolid, which is a synthetic antibacterial agent of the oxazolidinone class. The chemical name for linezolid is (S)-N-[[3-[3-Fluoro-4-(4-morpholinyl)phenyl]-2-oxo-5-oxazolidinyl] methyl]-acetamide. The empirical formula is C 16 H 20 FN 3 O 4 . Its molecular weight is 337.35, and its chemical structure is represented below: ZYVOX I.V. Injection is supplied as a ready-to-use sterile isotonic solution for intravenous infusion. Each mL contains 2 mg of linezolid. Inactive ingredients are sodium citrate, citric acid, and dextrose in an aqueous vehicle for intravenous administration. The sodium (Na + ) content is 0.38 mg/mL (5 mEq/300-mL bag and 1.7 mEq/100-mL bag). ZYVOX Tablet for oral administration contains 600 mg linezolid as a film-coated compressed tablet. Inactive ingredients are corn starch, microcrystalline cellulose, hydroxypropylcellulose, sodium starch glycolate, magnesium stearate, hypromellose, polyethylene glycol, titanium dioxide, and carnauba wax. The sodium (Na + ) content is 2.92 mg per 600-mg tablet (0.1 mEq/tablet). ZYVOX for Oral Suspension is supplied as an orange-flavored granule/powder for constitution into a suspension for oral administration. Following constitution, each 5 mL contains 100 mg of linezolid. Inactive ingredients are sucrose, citric acid, sodium citrate, microcrystalline cellulose and carboxymethylcellulose sodium, aspartame, xanthan gum, mannitol, sodium benzoate, colloidal silicon dioxide, sodium chloride, and flavors [ see Patient Counseling Information (17) ]. The sodium (Na + ) content is 8.52 mg/5 mL (0.4 mEq/5 mL). 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 ZYVOX I.V. Injection is available in single-use, ready-to-use flexible plastic infusion bags in a foil laminate overwrap. The infusion bags and ports are latex-free. The infusion bags are available in the following package sizes: 100 mL bag (200 mg linezolid) NDC 0009-5137-01 100 mL bag (200 mg linezolid) × 10 NDC 0009-5137-04 300 mL bag (600 mg linezolid) NDC 0009-5140-01 300 mL bag (600 mg linezolid) × 10 NDC 0009-5140-04 16.2 Tablets ZYVOX Tablets are available as follows: 600 mg (white, capsule-shaped, film-coated tablets printed with "ZYVOX 600 mg") 100 tablets in HDPE bottle NDC 0009-5135-01 20 tablets in HDPE bottle NDC 0009-5135-02 Unit dose packages of 30 tablets NDC 0009-5135-03 600 mg (white, capsule-shaped, film-coated tablets debossed with "ZYV" on one side and "600" on the other) 20 tablets in HDPE bottle NDC 0009-5138-02 Unit dose packages of 30 tablets NDC 0009-5138-03 16.3 Oral Suspension ZYVOX for Oral Suspension is available as a dry, white to off-white, orange-flavored granule/powder. When constituted as directed, each bottle will contain 150 mL of a suspension providing the equivalent of 100 mg of linezolid per each 5 mL. ZYVOX for Oral Suspension is supplied as follows: 100 mg/5 mL in 240-mL glass bottles NDC 0009-5136-01 16.4 Storage and Handling Store at 25°C (77°F). Protect from light. Keep bottles tightly closed to protect from moisture. It is recommended that the infusion bags be kept in the overwrap until ready to use. Each overwrap contains a peel-off label. Apply the peel- off label to the infusion bag for barcode scanning before use. Protect infusion bags from freezing.