Sivextro (Tedizolid Phosphate)
Oxazolidinone antibiotic for acute bacterial skin and skin structure infections
Quick Facts About Sivextro
Key Takeaways About Sivextro
- Short treatment course: Sivextro requires only 6 days of once-daily dosing, making it one of the shortest antibiotic courses for skin infections
- Effective against MRSA: Clinically proven to treat infections caused by methicillin-resistant Staphylococcus aureus and other resistant Gram-positive bacteria
- Take with or without food: The tablet can be taken regardless of meals, improving convenience and adherence
- Watch for serotonin syndrome: Use caution when combining with serotonergic drugs such as SSRIs, MAO inhibitors, or triptans
- Complete the full course: All 6 tablets must be taken to ensure effective treatment, even if symptoms improve earlier
What Is Sivextro and What Is It Used For?
Sivextro (tedizolid phosphate) is a next-generation oxazolidinone antibiotic specifically designed to treat acute bacterial skin and skin structure infections (ABSSSI). It works by inhibiting bacterial protein synthesis, effectively stopping the growth of Gram-positive bacteria including MRSA.
Sivextro contains the active substance tedizolid phosphate, which is a prodrug. After you swallow the tablet, enzymes called phosphatases in your body convert it into the active form, tedizolid. This active compound then targets and inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S bacterial ribosomal subunit, preventing the formation of a functional 70S initiation complex that bacteria need to produce essential proteins for their survival and reproduction.
The medication is approved for treating ABSSSI, which includes conditions such as cellulitis and erysipelas (bacterial skin infections causing redness and swelling), wound infections, and major cutaneous abscesses. These infections are often caused by bacteria such as Staphylococcus aureus (including MRSA), Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group, and Enterococcus faecalis.
Clinical trials, specifically the ESTABLISH-1 and ESTABLISH-2 studies, demonstrated that Sivextro 200 mg once daily for 6 days was non-inferior to linezolid 600 mg twice daily for 10 days in treating ABSSSI. These pivotal trials included over 1,300 patients and confirmed that the shorter, once-daily dosing regimen of tedizolid was as effective as the established standard of care.
Both Sivextro and linezolid belong to the oxazolidinone class, but Sivextro offers several advantages: a shorter treatment course (6 days vs. 10-14 days), once-daily dosing, and potentially fewer drug interactions due to weaker monoamine oxidase (MAO) inhibitory activity. However, linezolid has broader approved indications including pneumonia and certain types of bacteremia.
Sivextro is suitable for use in adults as well as adolescents and children who weigh at least 35 kg. For younger patients or those weighing less than 35 kg, tedizolid phosphate is available in an intravenous formulation as a powder for concentrate for solution for infusion.
What Should You Know Before Taking Sivextro?
Before starting Sivextro, your doctor needs to know about your complete medical history, including any allergies, kidney problems, history of bleeding disorders, and all other medications you are taking—particularly antidepressants, migraine medications, and opioids.
Contraindications
You should not take Sivextro if you are allergic to tedizolid phosphate or any of the other ingredients in the tablet. These inactive ingredients include microcrystalline cellulose, mannitol, povidone, crospovidone, and magnesium stearate in the tablet core, and polyvinyl alcohol, titanium dioxide (E171), macrogol, talc, and yellow iron oxide (E172) in the film coating.
If you have experienced an allergic reaction to other oxazolidinone antibiotics such as linezolid or cycloserine, inform your doctor before starting treatment, as cross-reactivity may occur.
Warnings and Precautions
Speak with your doctor or nurse before taking Sivextro if any of the following apply to you:
- Diarrhea history: If you have had diarrhea during or up to 2 months after taking antibiotics previously, you may be at increased risk for Clostridioides difficile-associated diarrhea (CDAD), a potentially serious condition caused by disruption of normal gut bacteria
- Bleeding tendency: If you have a history of bleeding or easy bruising, which may indicate low platelet counts (thrombocytopenia). Sivextro, like other oxazolidinones, may cause myelosuppression
- Kidney problems: While no dose adjustment is necessary for patients with renal impairment, your doctor should be aware of any kidney conditions
- Serotonergic medications: If you take antidepressants (SSRIs, SNRIs, tricyclics, MAO inhibitors), opioids, or triptans for migraine, as the combination with Sivextro may lead to serotonin syndrome
Serotonin syndrome is a potentially life-threatening condition that may occur when Sivextro is combined with serotonergic drugs. Symptoms include confusion, difficulty concentrating, fever, overactive reflexes, poor coordination of muscle movements, rapid heart rate, and agitation. Seek immediate medical attention if you experience these symptoms.
Antibiotic resistance: Bacteria can become resistant to antibiotic treatment over time. This means that antibiotics may no longer be effective at stopping bacterial growth and treating your infection. Your doctor will determine whether Sivextro is appropriate for your specific infection. Never take antibiotics without a prescription, and always complete the prescribed course.
Extended use precautions: Sivextro has been studied for 6-day courses. Certain side effects observed with linezolid or other oxazolidinones during longer treatment durations may also potentially occur with tedizolid. Contact your doctor immediately if you experience any of the following during treatment:
- Low white blood cell counts (increased susceptibility to infection)
- Anemia (low red blood cell count, causing fatigue and pallor)
- Unusual bleeding or easy bruising
- Loss of sensation in hands and feet (numbness, tingling, or severe pain; peripheral neuropathy)
- Vision problems such as blurred vision, changes in color perception, difficulty seeing detail, or reduced visual field (optic neuropathy)
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, are planning to have a baby, or are breastfeeding, talk to your doctor or pharmacist before taking Sivextro. The safety of tedizolid during pregnancy has not been fully established in humans, and it is unknown whether the drug passes into breast milk. Your doctor will weigh the potential benefits against the possible risks before prescribing this medication during pregnancy or breastfeeding.
Driving and operating machinery: Sivextro may cause dizziness or fatigue. If you experience either of these side effects, avoid driving or using machinery until the symptoms have resolved.
How Does Sivextro Interact with Other Drugs?
Sivextro can interact with several classes of medications, most notably serotonergic drugs (antidepressants, triptans, opioids) due to its weak MAO inhibitory activity, and certain cancer drugs and statins due to effects on drug transport proteins (BCRP).
Tedizolid is a weak, reversible inhibitor of monoamine oxidase (MAO), an enzyme that breaks down neurotransmitters such as serotonin, norepinephrine, and dopamine. While the inhibition is considerably weaker than that of linezolid, there remains a potential for interaction with serotonergic agents, particularly during the short 6-day treatment course. Additionally, tedizolid inhibits the breast cancer resistance protein (BCRP) transporter, which may affect the absorption and elimination of certain drugs that are substrates of this transporter.
Always inform your doctor or pharmacist about all medications you are currently taking, have recently taken, or might take in the future. This includes prescription medications, over-the-counter drugs, vitamins, and herbal supplements.
Major Interactions
| Drug / Class | Examples | Risk | Recommendation |
|---|---|---|---|
| MAO Inhibitors | Phenelzine, isocarboxazid, selegiline, moclobemide | Serotonin syndrome; hypertensive crisis | Avoid combination; allow washout period |
| SSRIs | Fluoxetine, sertraline, paroxetine, citalopram, fluvoxamine | Serotonin syndrome | Use with caution; monitor for symptoms |
| SNRIs | Duloxetine, venlafaxin | Serotonin syndrome | Use with caution; monitor closely |
| Tricyclic antidepressants | Amitriptyline, imipramine, clomipramine, doxepin, dosulepin | Serotonin syndrome; changes in blood pressure | Use with caution; monitor for symptoms |
| Triptans | Sumatriptan, zolmitriptan | Serotonin syndrome | Avoid if possible during treatment |
| Opioids | Fentanyl, tramadol, meperidine | Serotonin syndrome | Use with caution; monitor closely |
Other Notable Interactions
| Drug / Class | Examples | Mechanism | Recommendation |
|---|---|---|---|
| Cancer drugs (BCRP substrates) | Imatinib, lapatinib, topotecan, methotrexate | BCRP inhibition may increase drug levels | Monitor for increased side effects |
| Statins (BCRP substrates) | Rosuvastatin, pitavastatin | BCRP inhibition may increase statin exposure | Monitor for muscle pain and elevated CK |
| DMARDs | Sulfasalazine, methotrexate | BCRP inhibition may alter drug disposition | Monitor for increased side effects |
It is important to note that while tedizolid has weaker MAO inhibitory activity compared to linezolid, clinical caution is still advised. The clinical significance of these interactions may be lower with the short 6-day treatment course, but patients should be monitored for any signs of serotonin syndrome or other adverse effects throughout the treatment period and for a few days afterward.
What Is the Correct Dosage of Sivextro?
The recommended dose of Sivextro is one 200 mg film-coated tablet taken once daily for 6 days. The tablet should be swallowed whole and can be taken with or without food.
Always take Sivextro exactly as your doctor or pharmacist has instructed. The simplicity of the once-daily regimen and the short 6-day course are designed to improve treatment adherence and minimize antibiotic exposure, thereby reducing the risk of resistance development.
Adults
Standard Adult Dose
200 mg orally once daily for 6 days. Take one tablet at the same time each day. The tablet may be taken with or without food or drink. Swallow the tablet whole; do not crush, chew, or split it.
No dose adjustment is necessary for elderly patients, patients with hepatic impairment, or patients with renal impairment, including those receiving hemodialysis. The pharmacokinetic profile of tedizolid remains consistent across these patient populations.
Children and Adolescents
Pediatric Dose (weighing 35 kg or more)
200 mg orally once daily for 6 days. Same as the adult dose. For adolescents and children weighing at least 35 kg, the 200 mg film-coated tablet is appropriate.
For children and adolescents weighing less than 35 kg, tedizolid phosphate is available as a powder for concentrate for solution for infusion (intravenous formulation). The dosing for this formulation is weight-based and determined by the treating physician.
Elderly Patients
Elderly Dose
200 mg orally once daily for 6 days. No dose adjustment is required in elderly patients. However, elderly patients may be more susceptible to certain adverse effects and should be monitored accordingly.
Missed Dose
If you forget to take your tablet, take the missed dose as soon as you remember, provided it is at least 8 hours before your next scheduled dose. If fewer than 8 hours remain until the next dose, skip the missed dose and take your next dose at the usual time. Do not take a double dose to make up for a forgotten one.
It is essential to complete all 6 tablets to finish the full treatment course, even if you have missed a dose. Stopping treatment early or missing multiple doses can allow bacteria to survive and become resistant, potentially causing the infection to return or worsen.
Overdose
If you have taken more tablets than prescribed, contact your doctor, pharmacist, or nearest emergency department as soon as possible. Bring the medication packaging with you so healthcare professionals can identify what you have taken.
In clinical studies, single doses of up to 1,200 mg were administered to healthy volunteers. The most commonly reported adverse effects at supratherapeutic doses were headache and nausea. Treatment for overdose is supportive, as there is no specific antidote for tedizolid. Hemodialysis does not significantly remove tedizolid from the body due to its high protein binding (approximately 70-90%).
If you stop taking Sivextro before completing the full 6-day course, your symptoms may worsen and the infection may return. Always consult your doctor before discontinuing treatment, even if you feel better.
What Are the Side Effects of Sivextro?
Like all medicines, Sivextro can cause side effects, although not everyone will experience them. The most common side effects include nausea, vomiting, headache, itching, fatigue, and dizziness. Contact your doctor immediately if you develop diarrhea during or after treatment.
In clinical trials involving more than 1,000 patients, Sivextro demonstrated a generally favorable safety profile compared to linezolid. Most side effects were mild to moderate in severity and resolved upon completion of the 6-day treatment course. Below is a comprehensive summary of reported side effects organized by frequency.
Common
May affect up to 1 in 10 people
- Nausea
- Vomiting
- Headache
- Generalized itching (pruritus)
- Fatigue
- Dizziness
Uncommon
May affect up to 1 in 100 people
- Infections: Fungal infections of skin, mouth, and vagina (oral/vaginal thrush); abscess (swollen, pus-filled lump); vaginal infection, inflammation, or itching; respiratory tract infection (sinuses, throat, chest)
- Skin: Itching (including allergic itching), hair loss, acne, red and/or itchy rash, hives (urticaria), excessive sweating
- Nervous system: Decreased or lost skin sensation, tingling or prickling sensation, drowsiness, abnormal sleep patterns, difficulty sleeping, nightmares, tremor or shaking
- Gastrointestinal: Dry mouth, constipation, indigestion, abdominal pain or discomfort, retching, stomach ulceration, bright red blood in stool, gastroesophageal reflux (heartburn), flatulence
- Eyes: Blurred vision, visual floaters (small dots drifting in field of vision)
- Cardiovascular: Hot flush or facial flushing, slow heart rate (bradycardia)
- Musculoskeletal: Joint pain, muscle cramps, back pain, neck pain, limb pain or discomfort, reduced grip strength
- Other: Anxiety, irritability, dehydration, poor diabetes control, abnormal taste, fever, swollen ankles and/or feet, swollen lymph nodes, allergic reaction, abnormal urine odor, abnormal blood test results
- Respiratory: Nasal dryness, chest congestion, cough
Not Known
Frequency cannot be estimated from available data
- Easy bleeding and bruising due to low platelet count (thrombocytopenia)
Diarrhea during or after antibiotic treatment may be a sign of Clostridioides difficile infection, a potentially serious complication. Do not take any medication to treat the diarrhea without first consulting your doctor, as some antidiarrheal agents can worsen this condition.
Reporting side effects: If you experience any side effects, including any not listed above, talk to your doctor or pharmacist. You can also report side effects directly to your national medicines regulatory authority. By reporting side effects, you help provide more information on the safety of this medicine.
How Should You Store Sivextro?
Store Sivextro at room temperature in the original packaging, out of sight and reach of children. No special storage conditions are required.
Keep the tablets in their original blister packaging until you are ready to take them. There are no special storage temperature requirements for Sivextro, so standard room conditions are appropriate. Protect the tablets from excessive moisture and keep them away from direct sunlight.
Do not use Sivextro after the expiry date printed on the carton and blister label after "EXP." The expiry date refers to the last day of the stated month. Once a tablet has been removed from its blister, it should be taken promptly.
Do not throw away medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures help to protect the environment and prevent accidental exposure to unused medications.
What Does Sivextro Contain?
Each Sivextro film-coated tablet contains 200 mg of tedizolid phosphate as the active substance, with several inactive ingredients in the tablet core and film coating.
Active Ingredient
Each film-coated tablet contains 200 mg tedizolid phosphate, the prodrug that is converted to the active moiety tedizolid in the body.
Inactive Ingredients
Tablet core: Microcrystalline cellulose, mannitol, povidone, crospovidone, and magnesium stearate.
Film coating: Polyvinyl alcohol, titanium dioxide (E171), macrogol, talc, and yellow iron oxide (E172).
Appearance and Packaging
Sivextro tablets are oval, yellow, film-coated, and marked with "TZD" on one side and "200" on the other side. They are supplied in perforated unit-dose blisters containing 6 × 1 tablets, corresponding to one complete treatment course.
Frequently Asked Questions About Sivextro
Sivextro (tedizolid phosphate) is used to treat acute bacterial skin and skin structure infections (ABSSSI) in adults and children weighing at least 35 kg. These infections include cellulitis, erysipelas, wound infections, and major cutaneous abscesses caused by susceptible Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). It is not effective against Gram-negative bacteria or viral infections.
The standard treatment course is 200 mg once daily for 6 days. This is notably shorter than many other antibiotics used for similar infections. It is essential to complete all 6 days of treatment even if you start feeling better before the course is finished, as stopping early can lead to antibiotic resistance and recurrence of infection.
Yes, Sivextro can be taken with or without food. Clinical studies have shown that food does not significantly affect the absorption or efficacy of tedizolid phosphate. You can take the tablet at whatever time of day is most convenient, but try to take it at approximately the same time each day for consistency.
Caution is required when taking Sivextro with serotonergic antidepressants such as SSRIs (e.g., fluoxetine, sertraline), SNRIs (e.g., venlafaxine, duloxetine), tricyclics (e.g., amitriptyline), and MAO inhibitors. Sivextro has weak MAO inhibitory activity that can potentially increase serotonin levels when combined with these medications, leading to serotonin syndrome. Always discuss all your medications with your doctor before starting Sivextro.
If you forget a dose, take it as soon as you remember, provided there are at least 8 hours until your next scheduled dose. If less than 8 hours remain, skip the missed dose and continue with your regular schedule. Never take a double dose to compensate. Make sure to complete all 6 tablets in the course, even if you missed a dose.
Yes, Sivextro is effective against methicillin-resistant Staphylococcus aureus (MRSA). In the ESTABLISH-1 and ESTABLISH-2 clinical trials, tedizolid demonstrated clinical success rates comparable to linezolid in patients with MRSA skin infections. Oxazolidinone antibiotics like tedizolid have a unique mechanism of action that makes them effective against many resistant Gram-positive organisms.
References and Sources
- European Medicines Agency (EMA). Sivextro (tedizolid phosphate) — Summary of Product Characteristics (SmPC). Last updated 2025. Available at: EMA — Sivextro
- Prokocimer P, De Anda C, Fang E, Mehra P, Das A. Tedizolid phosphate vs linezolid for treatment of acute bacterial skin and skin structure infections: the ESTABLISH-1 randomized trial. JAMA. 2013;309(6):559-569. doi:10.1001/jama.2013.241
- Moran GJ, Fang E, Corey GR, Das AF, De Anda C, Prokocimer P. Tedizolid for 6 days versus linezolid for 10 days for acute bacterial skin and skin-structure infections (ESTABLISH-2): a randomised, double-blind, phase 3, non-inferiority trial. Lancet Infect Dis. 2014;14(8):696-705. doi:10.1016/S1473-3099(14)70737-6
- U.S. Food and Drug Administration (FDA). Sivextro (tedizolid phosphate) — Prescribing Information. Available at: FDA.gov
- World Health Organization (WHO). WHO Model List of Essential Medicines — 23rd List, 2023. Geneva: WHO; 2023.
- Infectious Diseases Society of America (IDSA). Practice Guidelines for the Diagnosis and Management of Skin and Soft Tissue Infections: 2014 Update. Clin Infect Dis. 2014;59(2):e10-e52.
- Burdette SD, Trotman R. Tedizolid: The First Once-Daily Oxazolidinone Class Antibiotic. Clin Infect Dis. 2015;61(8):1315-1321.
- British National Formulary (BNF). Tedizolid phosphate. NICE Evidence Services. Available at: bnf.nice.org.uk
Editorial Team
This article has been written and reviewed by the iMedic Medical Editorial Team, comprising licensed physicians with expertise in infectious disease, clinical pharmacology, and antimicrobial therapy.
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