ZYVOX® Adverse Reactions

(linezolid)

6 ADVERSE REACTIONS

The following clinically significant adverse reactions are described elsewhere in the labeling:

•
Myelosuppression [see Warnings and Precautions (5.1)]
•
Peripheral and Optic Neuropathy [see Warnings and Precautions (5.2)]
•
Serotonin Syndrome [see Warnings and Precautions (5.3)]
•
Clostridioides difficile-Associated Diarrhea [see Warnings and Precautions (5.5)]
•
Lactic Acidosis [see Warnings and Precautions (5.7)]
•
Convulsions [see Warnings and Precautions (5.8)]
•
Rhabdomyolysis [see Warnings and Precautions (5.9)]
•
Hypoglycemia [see Warnings and Precautions (5.10)]
•
Hyponatremia and/or Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) [see Warnings and Precautions (5.11)]

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 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 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 REACTIONSUncomplicated Skin and Skin Structure InfectionsAll 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*
(n=1464)
*
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.

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 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 Comparator-Controlled Clinical Trials
ADVERSE REACTIONSUncomplicated Skin and Skin Structure Infections*All Other Indications†
ZYVOX
(n=248)		Cefadroxil
(n=251)		ZYVOX
(n=215)		Vancomycin
(n=101)
*
Patients 5 through 11 years of age received ZYVOX 10 mg/kg by mouth every 12 hours or cefadroxil 15 mg/kg by mouth every 12 hours. Patients 12 years or older received ZYVOX 600 mg by mouth every 12 hours or cefadroxil 500 mg by mouth every 12 hours.
†
Patients from birth through 11 years of age received ZYVOX 10 mg/kg intravenously by mouth every 8 hours or vancomycin 10 to 15 mg/kg intravenously every 6–24 hours, depending on age and renal clearance.

Diarrhea

7.8

8.0

10.8

12.1

Vomiting

2.9

6.4

9.4

9.1

Headache

6.5

4.0

0.9

0

Anemia

0

0

5.6

7.1

Thrombocytopenia

0

0

4.7

2.0

Nausea

3.7

3.2

1.9

0

Generalized abdominal pain

2.4

2.8

0.9

2.0

Localized abdominal pain

2.4

2.8

0.5

1.0

Loose stools

1.6

0.8

2.3

3.0

Eosinophilia

0.4

0.8

1.9

1.0

Pruritus at non-application site

0.8

0.4

1.4

2.0

Vertigo

1.2

0.4

0

0

Of the pediatric patients treated for uSSSIs, 1.6% 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 0.9% of ZYVOX-treated and 6.1% of comparator-treated patients.

Laboratory Abnormalities

ZYVOX has been associated with thrombocytopenia when used in doses up to and including 600 mg every 12 hours for up to 28 days. In Phase 3 comparator-controlled trials, the percentage of adult patients who developed a substantially low platelet count (defined as less than 75% of lower limit of normal and/or baseline) was 2.4% (range among studies: 0.3 to 10.0%) with ZYVOX and 1.5% (range among studies: 0.4 to 7.0%) with a comparator. In a study of hospitalized pediatric patients ranging in age from birth through 11 years, the percentage of patients who developed a substantially low platelet count (defined as less than 75% of lower limit of normal and/or baseline) was 12.9% with ZYVOX and 13.4% with vancomycin. In an outpatient study of pediatric patients aged from 5 through 17 years, the percentage of patients who developed a substantially low platelet count was 0% with ZYVOX and 0.4% with cefadroxil. Thrombocytopenia associated with the use of ZYVOX appears to be dependent on duration of therapy (generally greater than 2 weeks of treatment). The platelet counts for most patients returned to the normal range/baseline during the follow-up period. No related clinical adverse events were identified in Phase 3 clinical trials in patients developing thrombocytopenia. Bleeding events were identified in thrombocytopenic patients in a compassionate use program for ZYVOX; the role of linezolid in these events cannot be determined [see Warnings and Precautions (5.1)].

Changes seen in other laboratory parameters, without regard to drug relationship, revealed no substantial differences between ZYVOX and the comparators. These changes were generally not clinically significant, did not lead to discontinuation of therapy, and were reversible. The incidence of adult and pediatric patients with at least one substantially abnormal hematologic or serum chemistry value is presented in Tables 4, 5, 6, and 7.

Table 4. Percent of Adult Patients who Experienced at Least One Substantially Abnormal* Hematology Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure InfectionsAll Other Indications
ZYVOX
400 mg every 12 hours		Clarithromycin
250 mg every 12 hours		ZYVOX
600 mg every 12 hours		All Other Comparators†
*
<75% (<50% for neutrophils) of Lower Limit of Normal (LLN) for values normal at baseline;
<75% (<50% for neutrophils) of LLN and of baseline for values abnormal at baseline.
†
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.

Hemoglobin (g/dL)

0.9

0.0

7.1

6.6

Platelet count (× 103/mm3)

0.7

0.8

3.0

1.8

WBC (× 103/mm3)

0.2

0.6

2.2

1.3

Neutrophils (× 103/mm3)

0.0

0.2

1.1

1.2

Table 5. Percent of Adult Patients who Experienced at Least One Substantially Abnormal* Serum Chemistry Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure InfectionsAll Other Indications
ZYVOX
400 mg every 12 hours		Clarithromycin
250 mg every 12 hours		ZYVOX
600 mg every 12 hours		All Other Comparators†
*
>2 × Upper Limit of Normal (ULN) for values normal at baseline;
>2 × ULN and >2 × baseline for values abnormal at baseline.
†
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.

AST (U/L)

1.7

1.3

5.0

6.8

ALT (U/L)

1.7

1.7

9.6

9.3

LDH (U/L)

0.2

0.2

1.8

1.5

Alkaline phosphatase (U/L)

0.2

0.2

3.5

3.1

Lipase (U/L)

2.8

2.6

4.3

4.2

Amylase (U/L)

0.2

0.2

2.4

2.0

Total bilirubin (mg/dL)

0.2

0.0

0.9

1.1

BUN (mg/dL)

0.2

0.0

2.1

1.5

Creatinine (mg/dL)

0.2

0.0

0.2

0.6

Table 6. Percent of Pediatric Patients who Experienced at Least One Substantially Abnormal* Hematology Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure Infections†All Other Indications‡
ZYVOXCefadroxilZYVOXVancomycin
*
<75% (<50% for neutrophils) of Lower Limit of Normal (LLN) for values normal at baseline;
<75% (<50% for neutrophils) of LLN and <75% (<50% for neutrophils, <90% for hemoglobin if baseline <LLN) of baseline for values abnormal at baseline.
†
Patients 5 through 11 years of age received ZYVOX 10 mg/kg by mouth every 12 hours or cefadroxil 15 mg/kg by mouth every 12 hours. Patients 12 years or older received ZYVOX 600 mg by mouth every 12 hours or cefadroxil 500 mg by mouth every 12 hours.
‡
Patients from birth through 11 years of age received ZYVOX 10 mg/kg intravenously by mouth every 8 hours or vancomycin 10 to 15 mg/kg intravenously every 6–24 hours, depending on age and renal clearance.

Hemoglobin (g/dL)

0.0

0.0

15.7

12.4

Platelet count (× 103/mm3)

0.0

0.4

12.9

13.4

WBC (× 103/mm3)

0.8

0.8

12.4

10.3

Neutrophils (× 103/mm3)

1.2

0.8

5.9

4.3

Table 7. Percent of Pediatric Patients who Experienced at Least One Substantially Abnormal* Serum Chemistry Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure Infections†All Other Indications‡
ZYVOXCefadroxilZYVOXVancomycin
*
>2 × Upper Limit of Normal (ULN) for values normal at baseline; >2 × ULN and >2 (>1.5 for total bilirubin) × baseline for values abnormal at baseline.
†
Patients 5 through 11 years of age received ZYVOX 10 mg/kg by mouth every 12 hours or cefadroxil 15 mg/kg by mouth every 12 hours. Patients 12 years or older received ZYVOX 600 mg mouth every 12 hours or cefadroxil 500 mg by mouth every 12 hours.
‡
Patients from birth through 11 years of age received ZYVOX 10 mg/kg intravenously/by mouth every 8 hours or vancomycin 10 to 15 mg/kg intravenously every 6–24 hours, depending on age and renal clearance.

ALT (U/L)

0.0

0.0

10.1

12.5

Lipase (U/L)

0.4

1.2

---

---

Amylase (U/L)

---

---

0.6

1.3

Total bilirubin (mg/dL)

---

---

6.3

5.2

Creatinine (mg/dL)

0.4

0.0

2.4

1.0

6.2 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of ZYVOX. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

•
Anaphylaxis, angioedema, bullous skin disorders including severe cutaneous adverse reactions (SCAR) such as toxic epidermal necrolysis and Stevens-Johnson syndrome, and hypersensitivity vasculitis.
•
Myelosuppression (including anemia, leukopenia, pancytopenia, and thrombocytopenia). Thrombocytopenia has been reported more often in patients with severe renal impairment and in patients with moderate to severe hepatic impairment [see Warnings and Precautions (5.1)]; sideroblastic anemia.
•
Peripheral neuropathy, and optic neuropathy sometimes progressing to loss of vision [see Warnings and Precautions (5.2)].
•
Serotonin syndrome has been reported in patients receiving concomitant serotonergic agents, including antidepressants such as selective serotonin reuptake inhibitors (SSRIs) and opioids, and ZYVOX [see Warnings and Precautions (5.3)].
•
Lactic acidosis [see Warnings and Precautions (5.7)]. Although these reports have primarily been in patients treated for longer than the maximum recommended duration of 28 days, these events have also been reported in patients receiving shorter courses of therapy.
•
Convulsions [see Warnings and Precautions (5.8)].
•
Rhabdomyolysis [see Warnings and Precautions (5.9)].
•
Hypoglycemia, including symptomatic episodes [see Warnings and Precautions (5.10)].
•
Hyponatremia and/or Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) [see Warnings and Precautions (5.11)].
•
Superficial tooth discoloration and tongue discoloration have been reported with the use of linezolid. The tooth discoloration was removable with professional dental cleaning (manual descaling) in cases with known outcome.

Find ZYVOX® medical information:

Find ZYVOX® medical information:

Our scientific content is evidence-based, scientifically balanced and non-promotional. It undergoes rigorous internal medical review and is updated regularly to reflect new information.

ZYVOX® Quick Finder

Prescribing Information
Download Prescribing Information

Health Professional Information

Adverse Reactions

6 ADVERSE REACTIONS

The following clinically significant adverse reactions are described elsewhere in the labeling:

•
Myelosuppression [see Warnings and Precautions (5.1)]
•
Peripheral and Optic Neuropathy [see Warnings and Precautions (5.2)]
•
Serotonin Syndrome [see Warnings and Precautions (5.3)]
•
Clostridioides difficile-Associated Diarrhea [see Warnings and Precautions (5.5)]
•
Lactic Acidosis [see Warnings and Precautions (5.7)]
•
Convulsions [see Warnings and Precautions (5.8)]
•
Rhabdomyolysis [see Warnings and Precautions (5.9)]
•
Hypoglycemia [see Warnings and Precautions (5.10)]
•
Hyponatremia and/or Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) [see Warnings and Precautions (5.11)]

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 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 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 REACTIONSUncomplicated Skin and Skin Structure InfectionsAll 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*
(n=1464)
*
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.

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 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 Comparator-Controlled Clinical Trials
ADVERSE REACTIONSUncomplicated Skin and Skin Structure Infections*All Other Indications†
ZYVOX
(n=248)		Cefadroxil
(n=251)		ZYVOX
(n=215)		Vancomycin
(n=101)
*
Patients 5 through 11 years of age received ZYVOX 10 mg/kg by mouth every 12 hours or cefadroxil 15 mg/kg by mouth every 12 hours. Patients 12 years or older received ZYVOX 600 mg by mouth every 12 hours or cefadroxil 500 mg by mouth every 12 hours.
†
Patients from birth through 11 years of age received ZYVOX 10 mg/kg intravenously by mouth every 8 hours or vancomycin 10 to 15 mg/kg intravenously every 6–24 hours, depending on age and renal clearance.

Diarrhea

7.8

8.0

10.8

12.1

Vomiting

2.9

6.4

9.4

9.1

Headache

6.5

4.0

0.9

0

Anemia

0

0

5.6

7.1

Thrombocytopenia

0

0

4.7

2.0

Nausea

3.7

3.2

1.9

0

Generalized abdominal pain

2.4

2.8

0.9

2.0

Localized abdominal pain

2.4

2.8

0.5

1.0

Loose stools

1.6

0.8

2.3

3.0

Eosinophilia

0.4

0.8

1.9

1.0

Pruritus at non-application site

0.8

0.4

1.4

2.0

Vertigo

1.2

0.4

0

0

Of the pediatric patients treated for uSSSIs, 1.6% 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 0.9% of ZYVOX-treated and 6.1% of comparator-treated patients.

Laboratory Abnormalities

ZYVOX has been associated with thrombocytopenia when used in doses up to and including 600 mg every 12 hours for up to 28 days. In Phase 3 comparator-controlled trials, the percentage of adult patients who developed a substantially low platelet count (defined as less than 75% of lower limit of normal and/or baseline) was 2.4% (range among studies: 0.3 to 10.0%) with ZYVOX and 1.5% (range among studies: 0.4 to 7.0%) with a comparator. In a study of hospitalized pediatric patients ranging in age from birth through 11 years, the percentage of patients who developed a substantially low platelet count (defined as less than 75% of lower limit of normal and/or baseline) was 12.9% with ZYVOX and 13.4% with vancomycin. In an outpatient study of pediatric patients aged from 5 through 17 years, the percentage of patients who developed a substantially low platelet count was 0% with ZYVOX and 0.4% with cefadroxil. Thrombocytopenia associated with the use of ZYVOX appears to be dependent on duration of therapy (generally greater than 2 weeks of treatment). The platelet counts for most patients returned to the normal range/baseline during the follow-up period. No related clinical adverse events were identified in Phase 3 clinical trials in patients developing thrombocytopenia. Bleeding events were identified in thrombocytopenic patients in a compassionate use program for ZYVOX; the role of linezolid in these events cannot be determined [see Warnings and Precautions (5.1)].

Changes seen in other laboratory parameters, without regard to drug relationship, revealed no substantial differences between ZYVOX and the comparators. These changes were generally not clinically significant, did not lead to discontinuation of therapy, and were reversible. The incidence of adult and pediatric patients with at least one substantially abnormal hematologic or serum chemistry value is presented in Tables 4, 5, 6, and 7.

Table 4. Percent of Adult Patients who Experienced at Least One Substantially Abnormal* Hematology Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure InfectionsAll Other Indications
ZYVOX
400 mg every 12 hours		Clarithromycin
250 mg every 12 hours		ZYVOX
600 mg every 12 hours		All Other Comparators†
*
<75% (<50% for neutrophils) of Lower Limit of Normal (LLN) for values normal at baseline;
<75% (<50% for neutrophils) of LLN and of baseline for values abnormal at baseline.
†
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.

Hemoglobin (g/dL)

0.9

0.0

7.1

6.6

Platelet count (× 103/mm3)

0.7

0.8

3.0

1.8

WBC (× 103/mm3)

0.2

0.6

2.2

1.3

Neutrophils (× 103/mm3)

0.0

0.2

1.1

1.2

Table 5. Percent of Adult Patients who Experienced at Least One Substantially Abnormal* Serum Chemistry Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure InfectionsAll Other Indications
ZYVOX
400 mg every 12 hours		Clarithromycin
250 mg every 12 hours		ZYVOX
600 mg every 12 hours		All Other Comparators†
*
>2 × Upper Limit of Normal (ULN) for values normal at baseline;
>2 × ULN and >2 × baseline for values abnormal at baseline.
†
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.

AST (U/L)

1.7

1.3

5.0

6.8

ALT (U/L)

1.7

1.7

9.6

9.3

LDH (U/L)

0.2

0.2

1.8

1.5

Alkaline phosphatase (U/L)

0.2

0.2

3.5

3.1

Lipase (U/L)

2.8

2.6

4.3

4.2

Amylase (U/L)

0.2

0.2

2.4

2.0

Total bilirubin (mg/dL)

0.2

0.0

0.9

1.1

BUN (mg/dL)

0.2

0.0

2.1

1.5

Creatinine (mg/dL)

0.2

0.0

0.2

0.6

Table 6. Percent of Pediatric Patients who Experienced at Least One Substantially Abnormal* Hematology Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure Infections†All Other Indications‡
ZYVOXCefadroxilZYVOXVancomycin
*
<75% (<50% for neutrophils) of Lower Limit of Normal (LLN) for values normal at baseline;
<75% (<50% for neutrophils) of LLN and <75% (<50% for neutrophils, <90% for hemoglobin if baseline <LLN) of baseline for values abnormal at baseline.
†
Patients 5 through 11 years of age received ZYVOX 10 mg/kg by mouth every 12 hours or cefadroxil 15 mg/kg by mouth every 12 hours. Patients 12 years or older received ZYVOX 600 mg by mouth every 12 hours or cefadroxil 500 mg by mouth every 12 hours.
‡
Patients from birth through 11 years of age received ZYVOX 10 mg/kg intravenously by mouth every 8 hours or vancomycin 10 to 15 mg/kg intravenously every 6–24 hours, depending on age and renal clearance.

Hemoglobin (g/dL)

0.0

0.0

15.7

12.4

Platelet count (× 103/mm3)

0.0

0.4

12.9

13.4

WBC (× 103/mm3)

0.8

0.8

12.4

10.3

Neutrophils (× 103/mm3)

1.2

0.8

5.9

4.3

Table 7. Percent of Pediatric Patients who Experienced at Least One Substantially Abnormal* Serum Chemistry Laboratory Value in Comparator-Controlled Clinical Trials with ZYVOX
Laboratory Assay Uncomplicated Skin and Skin Structure Infections†All Other Indications‡
ZYVOXCefadroxilZYVOXVancomycin
*
>2 × Upper Limit of Normal (ULN) for values normal at baseline; >2 × ULN and >2 (>1.5 for total bilirubin) × baseline for values abnormal at baseline.
†
Patients 5 through 11 years of age received ZYVOX 10 mg/kg by mouth every 12 hours or cefadroxil 15 mg/kg by mouth every 12 hours. Patients 12 years or older received ZYVOX 600 mg mouth every 12 hours or cefadroxil 500 mg by mouth every 12 hours.
‡
Patients from birth through 11 years of age received ZYVOX 10 mg/kg intravenously/by mouth every 8 hours or vancomycin 10 to 15 mg/kg intravenously every 6–24 hours, depending on age and renal clearance.

ALT (U/L)

0.0

0.0

10.1

12.5

Lipase (U/L)

0.4

1.2

---

---

Amylase (U/L)

---

---

0.6

1.3

Total bilirubin (mg/dL)

---

---

6.3

5.2

Creatinine (mg/dL)

0.4

0.0

2.4

1.0

6.2 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of ZYVOX. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

•
Anaphylaxis, angioedema, bullous skin disorders including severe cutaneous adverse reactions (SCAR) such as toxic epidermal necrolysis and Stevens-Johnson syndrome, and hypersensitivity vasculitis.
•
Myelosuppression (including anemia, leukopenia, pancytopenia, and thrombocytopenia). Thrombocytopenia has been reported more often in patients with severe renal impairment and in patients with moderate to severe hepatic impairment [see Warnings and Precautions (5.1)]; sideroblastic anemia.
•
Peripheral neuropathy, and optic neuropathy sometimes progressing to loss of vision [see Warnings and Precautions (5.2)].
•
Serotonin syndrome has been reported in patients receiving concomitant serotonergic agents, including antidepressants such as selective serotonin reuptake inhibitors (SSRIs) and opioids, and ZYVOX [see Warnings and Precautions (5.3)].
•
Lactic acidosis [see Warnings and Precautions (5.7)]. Although these reports have primarily been in patients treated for longer than the maximum recommended duration of 28 days, these events have also been reported in patients receiving shorter courses of therapy.
•
Convulsions [see Warnings and Precautions (5.8)].
•
Rhabdomyolysis [see Warnings and Precautions (5.9)].
•
Hypoglycemia, including symptomatic episodes [see Warnings and Precautions (5.10)].
•
Hyponatremia and/or Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) [see Warnings and Precautions (5.11)].
•
Superficial tooth discoloration and tongue discoloration have been reported with the use of linezolid. The tooth discoloration was removable with professional dental cleaning (manual descaling) in cases with known outcome.
Medication Guide

Health Professional Information

{{section_name_patient}}

{{section_body_html_patient}}

Resources

Didn’t find what you were looking for? Contact us.

MI Digital Assistant

Chat online with Pfizer Medical Information regarding your inquiry on a Pfizer medicine.

Call 800-438-1985*

*Speak with a Pfizer Medical Information Professional regarding your medical inquiry. Available 9AM-5PM ET Monday to Friday; excluding holidays.

Medical Inquiry

Submit a medical question for Pfizer prescription products.

Report Adverse Event

Pfizer Safety

To report an adverse event related to the Pfizer-BioNTech COVID-19 Vaccine, and you are not part of a clinical trial* for this product, click the link below to submit your information:

Pfizer Safety Reporting Site

*If you are involved in a clinical trial for this product, adverse events should be reported to your coordinating study site.

If you cannot use the above website, or would like to report an adverse event related to a different Pfizer product, please call Pfizer Safety at (800) 438-1985.

FDA Medwatch

You may also contact the U.S. Food and Drug Administration (FDA) directly to report adverse events or product quality concerns either online at www.fda.gov/medwatch or call (800) 822-7967.