Real‑World Evaluation of Omadacycline Switch Therapy for Multidrug‑Resistant Bacterial Pneumonia in Patients with Tigecycline Intolerance

Yuanchao Zhu,1,* Liang Liang,1,* Jiangang Zhang,2 Yang Ju31Department of Pharmacy, Beijing Hospital, National Center for Gerontology; National Clinical Research Center for Gerontology; The Key Laboratory of Geriatrics of NHC; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100730, People’s Republic of China; 2Department of Laboratory Medicine, Beijing Hospital, National Center for Gerontology; National Clinical Research Center for Gerontology; The Key Laboratory of Geriatrics of NHC; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100730, People’s Republic of China; 3Department of Pulmonary and Critical Care Medicine, Beijing Hospital, National Center for Gerontology; National Clinical Research Center for Gerontology; The Key Laboratory of Geriatrics of NHC; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100730, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yang Ju, Email [email protected]: Tigecycline represents a critical therapeutic option for multidrug‑resistant infection, however, its clinical utility is limited by adverse drug reaction (ADR), particularly hypofibrinogenemia and thrombocytopenia. This study aimed to evaluate the clinical characteristics and outcomes among patients with MDR pneumonia in a real‑world clinical setting.Methods: This single-center, retrospective study included hospitalized adults with pneumonia who were switched from tigecycline to omadacycline due to ADRs. A control group continued tigecycline treatment. Propensity score matching (1:5) was performed to balance baseline characteristics between the two groups. Clinical efficacy and safety outcomes were analyzed.Results: After screening, 26 patients formed the study cohort, while 622 patients constituted the final control group. Hematologic toxicity was the primary reason for tigecycline discontinuation, most commonly hypofibrinogenemia (61.5%) and thrombocytopenia (19.2%). Following the switch to omadacycline, complete resolution of ADRs was observed in 61.5% of patients, while 15.4% showed partial improvement. Only two patients (7.7%) experienced new-onset ADRs during omadacycline therapy (nausea and elevated transaminases). In the propensity score‑matched analysis (26 cases vs 130 controls), clinical effectiveness showed no statistically significant difference between the omadacycline and tigecycline groups (53.8% vs 61.5%; OR, 0.729; 95% CI, 0.312– 1.703; P=0.514).Conclusion: For tigecycline-intolerant patients with pneumonia, switching to omadacycline was associated with improvement or resolution of most pre-existing tigecycline-related hematologic adverse events, with no statistically significant difference in clinical effectiveness compared with tigecycline-treated controls.Keywords: omadacycline, tigecycline, drug intolerance, hypofibrinogenemia, thrombocytopenia