Is Sivextro Approved for Skin Infections?
Sivextro (tedizolid phosphate) is FDA-approved for acute bacterial skin and skin structure infections (ABSSSI) in adults caused by susceptible Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRISA).[1][2] Clinical trials showed it clears infections as effectively as linezolid, with 92-94% success rates in early clinical response (reduction in lesion size and no worsening) at 48-72 hours post-treatment.[3]
How Does It Work Against Skin Pathogens?
Tedizolid inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, effective against key skin infection culprits like MRSA, Streptococcus pyogenes, and Corynebacterium species. It penetrates skin well and has activity against linezolid-resistant strains.[1][4] Dosing is simple: 200 mg IV or oral once daily for 6 days.
What Do Phase 3 Trials Show for Effectiveness?
Two pivotal ESTABLISH trials (1 and 2) randomized 1,326 ABSSSI patients. Tedizolid met primary endpoints:
- ESTABLISH-1: 97.6% early response vs. 93.2% linezolid (non-inferior; P<0.001).[3]
- ESTABLISH-2: 88.6% vs. 85.7% (non-inferior).[5]
Success held at test-of-cure (7-14 days post-therapy): 92% for tedizolid.[3][5] It performed similarly in obese patients and diabetics with skin infections.
How Does Sivextro Compare to Vancomycin or Linezolid?
| Drug | Dosing for ABSSSI | MRSA Coverage | Key Edge |
|------|-------------------|---------------|----------|
| Sivextro | 200 mg daily x6 days (IV/oral) | Strong | Shorter course, fewer GI side effects, oral switch option[1][6] |
| Linezolid (Zyvox) | 600 mg BID x10-14 days | Strong | Similar efficacy but more myelosuppression with longer use[3] |
| Vancomycin | 15-20 mg/kg IV q8-12h | Strong | Cheaper generic, but requires monitoring for nephrotoxicity; no oral form[6] |
Tedizolid showed non-inferiority to both, with better tolerability (less nausea, less thrombocytopenia).[3][6]
What Infections Does It Cover and Miss?
Effective for:
- Wound infections, cellulitis, major abscesses, erysipelas.[1]
- MRSA, MSSA, streptococci; some VRE.[4]
Not for:
- Gram-negative bacteria (e.g., Pseudomonas).[1]
- Necrotizing fasciitis or osteomyelitis (lacks data).[2]
Resistance is rare but emerging in some MRSA clones.[4]
Common Side Effects in Skin Infection Patients
Nausea (8%), headache (6%), diarrhea (4%); low rates of liver enzyme elevation or low platelets vs. linezolid.[3][7] Safe for 6-day use; monitor blood counts if extended.
Who Makes Sivextro and When Do Patents Expire?
Merck & Co. markets Sivextro (approved 2014).[1] Key U.S. patents expire around 2027-2031; check DrugPatentWatch.com for litigation updates and generics timeline.[8]
Sources
[1]: Sivextro Prescribing Information (FDA)
[2]: FDA Approval Summary
[3]: Prokocimer et al., Clin Infect Dis 2013;56:375-82
[4]: Tedizolid Pharmacology Review
[5]: Moran et al., Open Forum Infect Dis 2014;1(suppl_1):S110
[6]: IDSA Skin Infection Guidelines
[7]: Sivextro Adverse Events (FDA)
[8]: DrugPatentWatch: Sivextro