Comparative Analysis of Adverse Drug Reactions Between Oritavancin Diphosphate and Oritavancin-HPβCD Using FAERS Data

Background: Acute bacterial skin and skin structure infections (ABSSSI) are serious infections predominantly caused by Gram-positive pathogens such as Staphylococcus aureus and Streptococcus pyogenes . Oritavancin, a lipoglycopeptide antibiotic, has emerged as a treatment alternative to vancomycin, especially in light of rising resistance. It is available in two formulations: oritavancin diphosphate (OD) and oritavancin complexed with 2-hydroxypropyl-β-cyclodextrin (OC), which differ in preparation, infusion time, and excipients. Objective: To compare the safety profiles of OD and OC by analyzing adverse drug reactions (ADRs) reported in the U.S. FDA Adverse Event Reporting System (FAERS), with a focus on differences potentially attributable to the HPβCD excipient in the OC formulation. Methods: This was a retrospective observational study evaluating ADRs associated with OD and OC reported in FAERS between January 2014 and June 2024. Reports were filtered to distinguish the two formulations explicitly, excluding generic “oritavancin” entries. Data were categorized by seriousness, gender, age group, source of report, and clinical outcome. Results: A total of 761 reports were retrieved for oritavancin diphosphate (OD) and 245 for oritavancin-HPβCD (OC). For both formulations, the peak in reporting occurred about 3 years after market introduction. The majority of events were classified as non-serious, accounting for 70.4% of OD and 71.8% of OC cases. Sex distribution differed slightly, with OD showing a predominance of female reports (38.2% vs 25.7% in OC), whereas OC presented more cases among males (34.7% vs 34.8% in OD). Clinical outcomes were largely comparable, though OD showed higher proportions of death (2.2% vs 0.8%), hospitalization (13.2% vs 10.7%), and life-threatening events (3.2% vs 0.8%). Age distribution indicated broader use of OD, including pediatric patients and a higher proportion of adults aged 18 to 64 years, while OC was more frequently reported in elderly patients (65-85 years). In both groups, most reports originated from healthcare professionals (>93%). Analysis of specific ADRs highlighted distinct patterns: infusion-related reactions, particularly chills, tremor, and flushing, were more frequent with OC, while OD was associated with higher rates of dermatological manifestations such as pruritus, urticaria, rash, and erythema. OC also showed a markedly higher proportion of errors related to multiple use of the single-use vial (9.9% vs 0.8%), whereas off-label use was more common with OD (9.6% vs 4.9%). Conclusions: Although both contain the same active ingredient, OD and OC differ in safety profiles due to their formulation and administration. Both formulations are considered safe, consistent with their product information. These findings highlight the need for formulation-specific safety considerations and standardized protocols in clinical practice.