Objective:To explore the effect of contezolid on platelet count in patients with severe pneumonia and analyze the risk factors.Methods:The study was designed as a retrospective case-control study. The research subjects were selected from patients with severe pneumonia who were admitted to the Department of Respiratory and Critical Care Medicine of Shaanxi Provincial People′s Hospital from July 1, 2022 to November 30, 2024 and were treated with contezolid or linezolid. The clinical data of patients were collected and the incidence of thrombocytopenia [platelet count (PLT)<100×10 9/L after medication], the PLT before and at 1 week of treatments, and the lowest PLT value during treatments were compared in patients treated with contezolid and linezolid. The patients were divided into 2 groups based on whether contezolid- related thrombocytopenia occurred. The clinical characteristics of the patients were compared, and the independent risk factors of contezolid-related thrombocytopenia were analyzed by binary logistic regression method. Results:A total of 175 patients were included, among whom 73 received contezolid and 102 received linezolid. There was no statistically significant difference in PLT between the 2 groups before medication ( P=0.364). Compared with patients treated with linezolid, the incidence of thrombocytopenia in patients treated with contezolid was lower [19.2% (14/73) vs. 40.2% (41/102)], and the PLT at 1 week of treatments and the lowest value of PLT during treatments were higher. The differences were all statistically significant (all P<0.05). Compared with patients without contezolid-related thrombocytopenia(59 patients), patients who developed thrombocytopenia after using contezolid had a longer duration of contezolid medication, lower PLT and creatinine clearance rate before medication, and higher procalcitonin and serum creatinine levels before medication. All these differences were statistically significant (all P<0.05). The results of binary logistic regression analysis showed that lower PLT [odds ratio ( OR)=0.971, 95% confidence interval ( CI): 0.950-0.992, P=0.008] and higher procalcitonin level ( OR=7.292, 95% CI: 1.067-49.814, P=0.043) before medication and longer duration of contezolid medication ( OR=1.165, 95% CI: 1.002-1.355, P=0.046) were the independent risk factors of contezolid-related thrombocytopenia. Conclusions:Compared with linezolid, contezolid has a relatively safer profile in the treatment of patients with severe pneumonia and the risk of thrombocytopenia after medication is lower. Patients with lower PLT and higher procalcitonin levels before medication, and those with a longer duration of contezolid medication have a higher risk of contezolid-related thrombocytopenia and should be closely monitored.

Objective:To explore the effect of contezolid on platelet count in patients with severe pneumonia and analyze the risk factors.Methods:The study was designed as a retrospective case-control study. The research subjects were selected from patients with severe pneumonia who were admitted to the Department of Respiratory and Critical Care Medicine of Shaanxi Provincial People′s Hospital from July 1, 2022 to November 30, 2024 and were treated with contezolid or linezolid. The clinical data of patients were collected and the incidence of thrombocytopenia [platelet count (PLT)<100×10 9/L after medication], the PLT before and at 1 week of treatments, and the lowest PLT value during treatments were compared in patients treated with contezolid and linezolid. The patients were divided into 2 groups based on whether contezolid- related thrombocytopenia occurred. The clinical characteristics of the patients were compared, and the independent risk factors of contezolid-related thrombocytopenia were analyzed by binary logistic regression method. Results:A total of 175 patients were included, among whom 73 received contezolid and 102 received linezolid. There was no statistically significant difference in PLT between the 2 groups before medication ( P=0.364). Compared with patients treated with linezolid, the incidence of thrombocytopenia in patients treated with contezolid was lower [19.2% (14/73) vs. 40.2% (41/102)], and the PLT at 1 week of treatments and the lowest value of PLT during treatments were higher. The differences were all statistically significant (all P<0.05). Compared with patients without contezolid-related thrombocytopenia(59 patients), patients who developed thrombocytopenia after using contezolid had a longer duration of contezolid medication, lower PLT and creatinine clearance rate before medication, and higher procalcitonin and serum creatinine levels before medication. All these differences were statistically significant (all P<0.05). The results of binary logistic regression analysis showed that lower PLT [odds ratio ( OR)=0.971, 95% confidence interval ( CI): 0.950-0.992, P=0.008] and higher procalcitonin level ( OR=7.292, 95% CI: 1.067-49.814, P=0.043) before medication and longer duration of contezolid medication ( OR=1.165, 95% CI: 1.002-1.355, P=0.046) were the independent risk factors of contezolid-related thrombocytopenia. Conclusions:Compared with linezolid, contezolid has a relatively safer profile in the treatment of patients with severe pneumonia and the risk of thrombocytopenia after medication is lower. Patients with lower PLT and higher procalcitonin levels before medication, and those with a longer duration of contezolid medication have a higher risk of contezolid-related thrombocytopenia and should be closely monitored.