A retrospective study of the efficacy of sulbactam in the treatment of patients with extensively drug-resistant Acinetobacter baumannii infections

Purpose Sulbactam (SBT) is one of the most significant treatments for patients with extensively drug-resistant Acinetobacter baumannii (XDR-AB). However, the efficacy and safety of SBT and its high dose regimen has not been well documented. This retrospective study aimed to assess the efficacy and safety of SBT-based treatment, particularly at high-dose (≥ 6g/day), for XDR-AB infection. Method A total of 52 XDR-AB infected patients treated with intravenous SBT at Peking Union Medical College Hospital were included. The primary outcome was 28-day all-cause mortality, while the secondary outcome was 14-day clinical response and the time of response. Results Among the patients, the 28-day all-cause mortality rate was 36.5% (19/52), and the favorable 14-day clinical response rate was 59.6% (31/52). The 28-day mortality was independently associated coinfection with gram-positive bacteria (GPB) and a shorter duration of therapy. Patients with intracranial infection might have a longer survival time. A favorable 14-day clinical response was associated with high dose SBT, and a longer treatment duration. However, the higher creatinine clearance (CrCl) associated with a worse clincal response. In addition, a higher SBT dosage was significantly correlated with a quicker clinical response. No adverse effects related were reported. Conclusion The single-agent formulation of SBT emerges as a promising alternative for the treatment of XDR-AB infection, such as intracranial infection, particularly at high doses (≥ 6g/day). Besides, longer duration of treatment correlates with higher survival rate and better favorable clinical response. Higher CrCl negatively correlates with favorable clinical response.