SIVEXTRO Safety
Adverse reactions in adult patients
The most common adverse reactions (≥2%) in adults for SIVEXTRO are nausea (7%), headache (5%), diarrhea (4%), vomiting (3%), and dizziness (2%).
In adult patients receiving SIVEXTRO intravenously, infusion- or injection-related adverse reactions including but not limited to: phlebitis, injection- or infusion-site pain or swelling, injection-site reaction, erythema, or induration, and infusion-related reaction occurred (4%).
The most common adverse reactions (>2%) in pediatric patients 12 years of age and older are phlebitis (3%) and increased hepatic transaminases (3%).
Selected adverse reactions occurring in ≥2% of adult patients
in pooled phase 3 ABSSSI clinical trials
SIVEXTRO (n = 1,037) | Linezolid (n = 1,000) | |
---|---|---|
Gastrointestinal disorders | ||
Nausea | 7% | 10% |
Diarrhea | 4% | 5% |
Vomiting | 3% | 5% |
Nervous system disorders | ||
Headache | 5% | 5% |
Dizziness | 2% | 2% |
Infusion- or injection-related adverse reactions* | ||
4% | 2% |
* Includes adverse reactions in the following body system or organ classes:
General disorders and administration site conditions, infections and infestations, injury, poisoning and procedural complications, and vascular disorders, including but not limited to, phlebitis, injection- or infusion-site pain, injection- or infusion-site swelling, injection-site reaction, injection-site erythema, injection-site induration, and infusion-related reaction.
Discontinuation rates
1% of adult patients receiving SIVEXTRO and 1.3% receiving linezolid
discontinued treatment due to adverse reactions.
Hematological abnormalities
Potentially clinically significant lowest laboratory values
in pooled phase 3 ABSSSI clinical trials in adults*,†
Laboratory assay | SIVEXTRO 200 mg (oral/intravenous once daily for 6 days) (n)‡ | Linezolid 600 mg (oral/intravenous twice daily for 10 days) (n)‡ |
---|---|---|
Hemoglobin (<9 g/dL females; <10.1 g/dL males) | (994) 3.4% | (957) 3.4% |
Platelet count (<112 x 103/mm3) | (989) 2.1% | (950) 3.8% |
Absolute neutrophil count (<0.8 x 103/mm3) | (980) 0.4% | (941) 0.6% |
* <75% (<50% for absolute neutrophil count) of lower limit of normal (LLN) for post-baseline measurements.
† Represents laboratory values within two days after the last dose of active drug.
‡ Number of subjects with at least one post-baseline test result that are within two days after the last dose of active drug.
The safety and effectiveness of SIVEXTRO for the treatment of ABSSSI have been established in pediatric patients aged 12 years and older. Use of SIVEXTRO for the treatment of ABSSSI is supported by evidence from adequate and well-controlled studies in adults with additional pharmacokinetic and safety data in pediatric patients aged 12 years and older. Safety and effectiveness of SIVEXTRO in pediatric patients below the age of 12 years have not been established.
Adverse reactions in pediatric patients
Adverse reactions were evaluated in 91 pediatric patients with ABSSSI ranging from 12 to <18 years of age treated with IV and/or oral SIVEXTRO 200 mg for 6 days and 29 patients treated with comparator agents for 10 days. The majority of pediatric patients treated with SIVEXTRO were male (64%) and white (88%).
Serious adverse reactions occurred in 1/91 (1%) of pediatric patients treated with SIVEXTRO and in none of the 29 patients treated with the comparator. Adverse reactions leading to discontinuation occurred in 1 (1%) pediatric patient in the SIVEXTRO arm and in none in the comparator arm.
The most common adverse reactions occurring in pediatric patients receiving SIVEXTRO in the ABSSSI clinical trial were phlebitis (3%), increased hepatic transaminases (alanine aminotransferase, aspartate aminotransferase), (3%), anemia, and vomiting (1%).
Safety has not been evaluated in pediatric patients under 12 years of age.
Potentially clinically significant lowest laboratory values
in the ABSSSI clinical trial in pediatric patients (12-<18 years)*,†
Laboratory assay | SIVEXTRO 200 mg (oral/intravenous once daily for 6 days) (n)‡ | Comparators§ (for 10 days) (n)‡ |
---|---|---|
Hemoglobin (<10.1 g/dL [males] <9 g/dL [females]) | (85) 2.4% | (26) 0.0% |
Platelet count (<112 x 103/mm3) | (82) 1.2% | (26) 0.0% |
Absolute neutrophil count (<0.8 x 103/mm3) | (85) 0.0% | (26) 0.0% |
* <75% (<50% for absolute neutrophil count) of lower limit of normal (LLN) for post-baseline measurements.
† Represents laboratory values within two days after the last dose of active drug.
‡ Number of subjects with at least one post-baseline test result that are within two days after the last dose of active drug.
§ 5 IV and 4 oral comparators selected per local standard of care.
Drug interactions
Increased Breast Cancer Resistance Protein (BCRP) substrate plasma concentrations
Orally administered SIVEXTRO inhibits BCRP in the intestine, which can increase the plasma concentrations of orally administered BCRP substrates, and the potential for adverse reactions. If possible, an interruption in the treatment of the co-administered BCRP substrates should be considered, especially for BCRP substrates with a narrow therapeutic index (eg, methotrexate or topotecan). If coadministration cannot be avoided, monitor for adverse reactions related to the concomitantly administered BCRP substrates, including rosuvastatin.
No known interactions with serotonergic agents
Serotonergic effects at doses of tedizolid phosphate up to 30-fold above the human equivalent dose did not differ from vehicle control in a mouse model that predicts serotonergic activity.
In phase 3 trials, subjects taking serotonergic agents including antidepressants such as selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, and serotonin 5-hydroxytryptamine (5-HT1) receptor agonists (triptans), meperidine, or buspirone were excluded.
No known interactions with adrenergic agents in adults
2 placebo-controlled crossover studies with SIVEXTRO (at steady state) showed no meaningful changes in blood pressure or heart rate in adults with pseudoephedrine, and the median tyramine dose required to cause an increase in systolic blood pressure (≥30 mmHg) was 325 mg with SIVEXTRO compared to 425 mg with placebo.
Palpitations were reported in 21/29 (72.4%) subjects exposed to SIVEXTRO in the tyramine challenge study vs 13/28 (46.4%) of placebo patients.
Monoamine oxidase inhibitors
Tedizolid is a reversible inhibitor of monoamine oxidase (MAO) in vitro. The interaction with MAO inhibitors could not be evaluated in phase 2 and 3 trials, as subjects taking such medications were excluded from the trials.