Relationship Between Patient’s Body Mass Index and Dalbavancin’s Effectiveness in the Treatment of Invasive Gram-Positive Infections

Abstract

Background:

Dalbavancin’s pharmacokinetic parameters suggest obesity may affect serum and tissue concentrations, but currently there is no outcome data in the obese population with invasive infections.

Objective:

The purpose of this study is to determine whether body mass index (BMI) correlates with dalbavancin 90-day treatment failure (TF) in patients with invasive infections.

Methods:

A multicenter, retrospective observational study analyzed adult patients who received one or more dose of dalbavancin 1500 mg for an invasive infection at 2 community teaching hospitals. Patients admitted ≥3 times within 90 days or received ≥28 days of intravenous antibiotics prior to the initiation of dalbavancin were excluded. The primary outcome was TF at 90 days defined as the need for additional antibiotics or surgery, intolerance, readmission, death, or lost to follow-up. Logistic regression models tested the relationship between BMI and TF. A secondary analysis removed patients lost to follow-up. A conditional probability plot was generated to display the relationship of BMI and TF.

Results:

Of 197 patients, 159 met inclusion criteria. Demographics included 64.8% males (n = 103), median age 46 years (34.5-60), and 48.4% (N = 77) persons who inject drugs. Bone/joint accounted for 50% (N = 80) of infections, with Staphylococcus aureus commonly isolated (N = 108, 67.9%). Sixty-eight patients experienced TF. The median BMI in the TF versus cure group was 26.0 kg/m² (21.0-30.3) and 26.0 kg/m² (23.0-30.5), P = 0.56. Significant predictors in the model included hospital site (OR = 0.28, 95% CI: 0.08-0.95) and methicillin-resistant S. aureus (OR = 3.01, 95% CI: 1.43-6.34). BMI was not a predictor of TF in the primary (OR = 1.00, 95% CI: 0.96-1.05) or secondary analysis (OR = 1.02, 95% CI: 0.97-1.07). The conditional probability plot found no relationship between BMI and TF in BMI <50 kg/m².

Conclusion and Relevance:

This observational study did not show an association between BMI and TF in patients treated with dalbavancin with invasive gram-positive infections.