Oritavancin FAERS Analysis Finds 48 Adverse-Event Signals

Key Takeaways

• U.S.-predominant FAERS reports naming oritavancin as the primary suspect contained disproportionate-reporting signals across multiple organ systems.
• Labeled chills had a prominent reporting signal, alongside signals for dyspnea, chest discomfort, and anaphylactic reaction.
• Hospitalization, life-threatening outcomes, and death were recorded in oritavancin primary-suspect reports.
• Adverse events with calculable onset were predominantly reported early after oritavancin initiation.

Oritavancin is approved for acute bacterial skin and skin-structure infection and is also used off label for more complex Gram-positive infections, sometimes with repeated doses. Xie, Zhou, Song, and Cui reviewed Food and Drug Administration Adverse Event Reporting System (FAERS) submissions from the third quarter of 2014 through the first quarter of 2025 in their retrospective oritavancin pharmacovigilance study.

Of 16,964,725 reports, 1,088 named oritavancin as the primary suspect. Investigators coded events using Medical Dictionary for Regulatory Activities (MedDRA) system organ class (SOC) and preferred term (PT) categories, excluding administrative and drug-use terms.

A signal required at least three reports and positive findings under every prespecified algorithm: reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS). Investigators described outcomes and time to onset, examined age and sex strata, and repeated signal detection without reports listing concomitant medications.

Investigators identified seven SOC-level and 48 PT-level signals spanning respiratory, skin, vascular, immune, and other categories; PT-level signals met all four algorithm thresholds. Most submissions originated in the United States.

Chills, an event listed in product labeling, appeared in 156 reports, with an ROR of 27.84. This labeled event provided a reference point for interpreting other reported symptoms. Dyspnea appeared in 98 reports, with an ROR of 3.41. Signals for hypoxia, throat tightness, tachypnea, and respiratory depression broadened the respiratory pattern. Chest discomfort appeared in 29 reports, with an ROR of 5.64. Anaphylactic reaction appeared in 25 reports, with an ROR of 9.07.

Voluntary reporting permits underreporting and selection bias; without an exposed-person denominator, reporting odds cannot be read as incidence. Incomplete narratives leave infection severity, indication, comorbidities, and concomitant treatment as possible confounders. Roughly half of submissions lacked age information, and nearly one-third lacked sex information, making subgroup patterns particularly tentative. Excluding reports with concomitant drugs did not resolve other sources of confounding or verify that reported events were medication-attributable.

In the authors’ interpretation, known labeled events appeared alongside additional respiratory, cardiovascular, neurologic, and musculoskeletal reporting signals.

Clinician Questions

Can FAERS data compare infusion-reaction risk between Orbactiv and Kimyrsa?

Xie and colleagues lacked sufficient product-specific information in oritavancin reports to compare infusion-reaction risk between Orbactiv and Kimyrsa.

Which oritavancin reports contributed to the time-to-onset analysis?

Investigators calculated the interval from oritavancin initiation to adverse-event onset only for FAERS reports containing both dates. Reports missing either the drug-start date or event-onset date were excluded from the timing analysis.