oritavancin
Brand: Orbactiv
Prototype: vancomycin
Drug Class: lipoglycopeptide antibiotic
Drug Family: antibiotic
Subclass: long-acting single-dose lipoglycopeptide
Organ Systems: infectious-disease
Mechanism of Action
Inhibits cell wall synthesis by binding peptidoglycan precursors and disrupts membrane integrity; its extremely long half-life (245 hours) enables single-dose treatment of ABSSSI.
D-Ala-D-Ala peptidoglycan precursorsbacterial cell membrane
Indications
- acute bacterial skin and skin structure infections (ABSSSI) including MRSA — single 1200 mg dose
Contraindications
- oritavancin hypersensitivity
- concurrent use of unfractionated heparin within 48 hours (inhibition of activated partial thromboplastin time assay)
Adverse Effects
Common
- headache
- nausea
- vomiting
- infusion-site reactions
Serious
- osteomyelitis (associated with single-dose therapy failures — ensure correct patient selection)
- C. difficile colitis
- anaphylaxis
- QTc prolongation
Pharmacokinetics (ADME)
| Absorption | IV only |
| Distribution | extensive tissue distribution; very high volume of distribution (87.6 L) |
| Metabolism | minimal |
| Excretion | fecal/renal; extremely slow elimination |
| Half-life | 245 hours (~10 days) |
| Onset | immediate (IV) |
| Peak | end of 3-hour infusion |
| Duration | single dose covers 7–10 days clinically |
| Protein Binding | 85% |
| Vd | very large (87.6 L) |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| warfarin | oritavancin inhibits CYP2C9 and CYP3A4; may increase warfarin exposure and INR | major |
| heparin (UFH) | falsely elevates aPTT for up to 48 hours; UFH infusion should not be initiated for 48 hours post-oritavancin | major |
Nursing Considerations
- Single 1200 mg dose infused over 3 hours; the main nursing advantage is eliminating the need for daily IV antibiotics in select outpatients.
- Counsel patients that anticoagulation monitoring (aPTT) will be unreliable for up to 48 hours after oritavancin; document clearly in the medical record.
- Assess patient suitability: uncomplicated ABSSSI only; do NOT use for suspected endocarditis, bacteremia, or osteomyelitis.
- Ensure adequate IV access; reconstitute according to manufacturer instructions and infuse over exactly 3 hours.
Clinical Pearls
- Oritavancin's 10-day half-life enables a single 1200 mg dose for the full treatment course of ABSSSI, potentially allowing same-day discharge from the ED — a major clinical and economic advantage.
- Oritavancin inhibits CYP2C9 and CYP3A4 enzymes for up to 2 weeks post-dose; patients on warfarin or other CYP-sensitive drugs require careful monitoring after oritavancin administration.
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.