Bottom line
Oritavancin is a semisynthetic lipoglycopeptide with three mechanisms of action (dual cell-wall synthesis inhibition and membrane disruption) and a very long half-life (~245 h). It is FDA-approved as a single 1,200 mg IV infusion for ABSSSI, offering a complete treatment course in one dose. Two products (Orbactiv and Kimyrsa) have different infusion durations (3 h vs 1 h) and preparation instructions.
Identity and composition
| Field | Verified information |
|---|---|
| Preferred name | Oritavancin |
| Key aliases | Orbactiv, Kimyrsa, LY333328 |
| Molecular/sequence identity | Semisynthetic lipoglycopeptide derivative of vancomycin with a 4'-chlorobiphenylmethyl group attached to the disaccharide amino group. Chemical name: [4"R]-22-O-(3-amino-2,3,6-trideoxy-3-C-methyl-α-L-arabino-hexopyranosyl)-N3''-[(4'-chloro[1,1'-biphenyl]-4-yl)methyl] vancomycin phosphate [1:2] [salt]. |
| Modifications/form | Diphosphate salt; lyophilized powder for IV infusion. Orbactiv — 3 h infusion; Kimyrsa — 1 h infusion (different formulation). |
| Stable identifiers | PubChem CID: 16136912; DrugBank: DB06404; ChEBI: CHEBI:136535; CAS: 171099-57-3 |
| Identity caveats | Two distinct commercial products have different doses, infusion durations, and preparation requirements. Oritavancin is a lipoglycopeptide, not a natural peptide. |
Development and approval status
| Jurisdiction | Status and indication | Product/source | As of |
|---|---|---|---|
| USA (FDA) | Approved — ABSSSI (adults) | Orbactiv (The Medicines Company); Kimyrsa (Melinta) | 2014 |
| EU (EMA) | Approved — ABSSSI (adults) | Orbactiv | 2015 |
Mechanism and pharmacology
Oritavancin has three mechanisms of action:
Inhibition of transglycosylation (polymerization) of peptidoglycan by binding to the stem peptide.
Inhibition of transpeptidation (cross-linking) by binding to the peptide bridging segments.
Disruption of bacterial membrane integrity, causing depolarization, permeabilization, and cell death.
These multiple mechanisms contribute to concentration-dependent bactericidal activity.
Pharmacokinetics: IV; half-life ~245-393 h; extensive tissue distribution; high protein binding (~85-90%); primarily feces excretion (unchanged); not CYP450 metabolized.
Evidence by claim
| Claim/indication | Stage | Grade | Best human evidence | Main result | Important limitations |
|---|---|---|---|---|---|
| ABSSSI (adults) | Approved | A | Two identically designed phase 3 RCTs (SOLO I/II; N=1,987); oritavancin 1,200 mg single dose vs vancomycin 1 g q12h × 7-10 d | ECR (48-72 h): 82.3% vs 78.9% (SOLO I); 80.1% vs 82.9% (SOLO II) — both met NI margin (-10%) | Heterogeneous comparator duration; no pediatric data |
Key studies
| Study | Design/population | Exposure studied | Endpoints and result | Limitations |
|---|---|---|---|---|
| SOLO I (NCT01252719) | Phase 3, DB, RCT; N=954; ABSSSI | Oritavancin 1,200 mg single IV dose vs vancomycin q12h × 7-10 d | ECR: 82.3% vs 78.9% (difference 3.4%, 95% CI -1.6, 8.4) — NI met | Vancomycin not blinded after day 10; 80% male in oritavancin arm |
| SOLO II (NCT01252732) | Phase 3, DB, RCT; N=1,005; ABSSSI | Same regimen | ECR: 80.1% vs 82.9% (difference -2.7%, 95% CI -7.5, 2.0) — NI met | Slightly lower oritavancin response vs SOLO I |
Dose and administration evidence
Approved labeled regimen
The label summary below is product-, indication-, and jurisdiction-specific; consult the full current label and a licensed clinician/pharmacist.
Orbactiv: 1,200 mg IV single dose over 3 h. Kimyrsa: 1,200 mg IV single dose over 1 h. No dose adjustment needed for mild or moderate renal or hepatic impairment (severe impairment not evaluated).
What is not established
Repeated dosing for complicated infections (studied but not FDA-approved).
Pediatric use (not approved).
Osteomyelitis, endocarditis, or prosthetic joint infections (off-label only).
Safety
Established label risks
Nausea, vomiting, headache, diarrhea, phlebitis, infusion-site pain.
Elevation of ALT/AST (incidence 2-8%).
Headache (most common AE).
Infusion reactions (flushing, pruritus, urticaria).
Osteomyelitis (noted as a post-treatment complication in some patients, likely reflecting disease progression rather than drug effect).
Human-study signals
Isolated reports of Clostridioides difficile infection following therapy.
No QTc prolongation signal.
Unknowns and product-quality risks
Two distinct products (Orbactiv, Kimyrsa) with different preparation instructions and infusion durations — not interchangeable without adjustment.
Must not be mixed with saline-containing diluents (use D5W only for Orbactiv; Kimyrsa compatible with saline).
Interactions and special populations
Coagulation test interference: oritavancin artificially prolongs aPTT for up to 120 h, PT/INR for up to 12 h, ACT for up to 24 h, and D-dimer for up to 72 h after a single dose. Use non-phospholipid-dependent tests (e.g., chromogenic Factor Xa assay) if aPTT monitoring is needed within 120 h. Contraindicated with IV unfractionated heparin for 120 h (5 days) after oritavancin administration because aPTT monitoring becomes unreliable; oritavancin does not anticoagulate in vivo. Weak inhibitor of CYP2C19 and CYP3A4; weak inducer of CYP3A4 and CYP2D6. No dose adjustment needed for mild or moderate renal or hepatic impairment (severe impairment not evaluated). Pregnant/lactating: no adequate data.
Regulatory, compounding, and sport notes
WADA status: not prohibited. No US federal CSA scheduling was identified as of 2026-08-06; state law and other jurisdictions were not assessed. US and EU authorizations for ABSSSI are product-specific.
Evidence gaps
Single-dose vs multi-dose regimens for deep-seated infections.
Use in patients weighing >120 kg (limited pharmacokinetic data).
Resistance mechanism: in vitro serial passage studies show S. aureus and E. faecalis can develop reduced susceptibility.
Comparison with dalbavancin (the two have never been directly compared in an RCT).
Search notes
Databases and registries: FDA label (accessdata.fda.gov), DailyMed, ClinicalTrials.gov, PubMed
Search terms: oritavancin, Orbactiv, Kimyrsa, lipoglycopeptide, ABSSSI, SOLO trial
Last searched: 2026-08-06
Inclusion emphasis: FDA/EMA labels, phase 3 RCTs
Sources
FDA prescribing information: ORBACTIV (oritavancin) for injection. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/206334s006lbl.pdf (accessed 2026-08-06).
DailyMed: ORBACTIV. Available at: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ff09a726-9f9b-4e30-b509-396781293220 (accessed 2026-08-06).
Corey GR, et al. Single-dose oritavancin in the treatment of acute bacterial skin infections. N Engl J Med. 2014;370(23):2180-90. DOI: 10.1056/NEJMoa1310422. (SOLO I)
Corey GR, et al. Single-dose oritavancin versus 7-10 days of vancomycin in the treatment of gram-positive acute bacterial skin and skin structure infections: the SOLO II noninferiority study. Clin Infect Dis. 2015;60(2):254-62. DOI: 10.1093/cid/ciu778.