Orbactiv, Kimyrsa
Evidence Grade A — Regulatory approved. 486 published studies. 20 registered clinical trials.
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Oritavancin (sold as Orbactiv and Kimyrsa) is an intravenous antibiotic that can cure a serious bacterial skin infection with a single hospital visit. Its remarkably long duration of action means one dose provides a full course of treatment that would otherwise require 7–10 days of twice-daily vancomycin infusions. This is particularly valuable for patients who face barriers to completing multi-day treatment courses.
486 published studies: 309 human, 12 animal, 136 in-vitro, 187 reviews
Oritavancin is marketed as Orbactiv (approved August 2014) and Kimyrsa (approved March 2021 as a faster 1-hour infusion). Indicated for acute bacterial skin and skin structure infections (ABSSSI) caused by susceptible gram-positive bacteria, including MRSA.
The single-dose regimen is oritavancin's key differentiator. In clinical trials (SOLO I and II), a single dose was non-inferior to 7–10 days of twice-daily vancomycin. This is particularly valuable in emergency department settings and for patients with unstable housing, active substance use, or other barriers to completing multi-day antibiotic courses. However, oritavancin interferes with coagulation laboratory tests for up to 120 hours after dosing, complicating monitoring in patients who also need anticoagulation.
Oritavancin kills bacteria through three simultaneous mechanisms, making it exceptionally potent. Like vancomycin, it binds the D-Ala-D-Ala target on cell wall building blocks. But it also directly disrupts the bacterial cell membrane through its fatty acid side chain, and uniquely, it blocks a second cell wall construction step (transpeptidation) that vancomycin cannot reach. This triple attack gives it activity against some bacteria that are resistant to vancomycin.
In two Phase III trials involving nearly 2,000 patients, a single dose of oritavancin was non-inferior to 7–10 days of twice-daily vancomycin for acute bacterial skin infections, including MRSA. The single-dose approach is especially useful in emergency department settings and for patients with unstable housing or other circumstances that make return visits difficult. The main clinical concern is interference with blood clotting laboratory tests — oritavancin can falsely elevate aPTT readings for up to five days after dosing, which complicates monitoring for patients who also need blood-thinning medications. Heparin is contraindicated for five days after a dose. There is no trial data supporting its use in bloodstream infections, endocarditis, or bone infections, though its long duration makes off-label use in these settings an area of clinical interest.
Oritavancin for CIED Infections With MDR Gram-positive Cocci
Anchoring Sequential Intermittent Long Acting Antimicrobials With Medication for Opioid Use Disorder (MOUD) for Invasive Infections Related to Opioid Use
Pathogenicity Factors of Staphylococcus Pettenkoferi in Foot Wounds and Osteitis in Diabetic Patients
Comparing Oral Versus Parenteral Antimicrobial Therapy
Study to Evaluate the Safety of Intravenous Oritavancin for the Treatment of Children With Skin Infections
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