Efficacy and safety of tigecycline for complicated urinary tract infection: a systematic review

Impact of Tigecycline on Coagulation in Severe Infections and Effect of Vitamin K1 Intervention: A Retrospective Single-Center Analysis

BACKGROUND Tigecycline is a tetracycline antibiotic used to treat gram-positive and gram-negative bacterial infections, and bleeding is a dose-dependent adverse effect. Vitamin K1 is a fat-soluble vitamin used to treat hemorrhagic conditions. This retrospective study from a single center included 920 patients treated with tigecycline for bacterial infections between January 2017 and December 2022 and aimed to evaluate the incidence of coagulopathy and the use of vitamin K1. MATERIAL AND METHODS A total of 220 patients were included and divided into a high-dose group (100 mg, every 12 h) and normal-dose group (50 mg, every 12 h) according to the treatment dose of tigecycline. Clinical characteristics and changes in coagulation indicators during tigecycline treatment were collected. Seventy-two patients were treated with vitamin K1, and the changes in coagulation indicators before and after treatment were compared. ANOVA and t test were used to analyze the effects of different doses of tigecycline on coagulation function and the intervention of vitamin K1. RESULTS Among 920 patients, the incidence of coagulopathy was 23.91%. In both groups, coagulopathy occurred on days 5 to 7 after administration, and the high-dose group had worse coagulation function than the normal-dose group, including activated partial thrombin time, prothrombin time, and fibrinogen (P<0.05). After treatment with vitamin K1, fibrinogen increased and activated partial thrombin time and prothrombin time were shortened in both groups (P<0.05 or P<0.01). CONCLUSIONS Tigecycline caused coagulopathy with dose and time dependence. Vitamin K1 can improve tigecycline-induced coagulopathy.

Tigecycline-Based Regimens for Complicated Urinary Tract Infections Caused by Carbapenem-Resistant Gram-Negative Bacteria: Case Series

There is existing controversy regarding the efficacy of tigecycline (TG) in treating complicated urinary tract infections (cUTIs) because of its pharmacokinetic concerns. We present three patients with cUTIs caused by carbapenem-resistant gram-negative (GN) pathogens successfully treated with high-dose tigecycline (HDT)-based regimens, as cefiderocol and aztreonam were not available in our country. The first case describes a 67-year-old patient with diabetes, prostate cancer, and double J ureteral stenting who was hospitalized with a febrile, complicated urinary tract infection (cUTI). Urine and blood cultures were positive for metallo-beta-lactamases (MBL)-producing extensively drug-resistant (XDR) Klebsiella pneumoniae (cefiderocol-susceptible). The synergy between TG and colistin using the in vitro E-test was demonstrated, and the patient was started on this regimen using HDT. Clinical and microbiological cures were achieved, and the patient was discharged home. The second case presents a 70-year-old patient with urethral pathology who was hospitalized with the diagnosis of a lower cUTI caused by an MBL-producing pan-drug-resistant (PDR) Klebsiella pneumoniae. The in vitro E-test showed synergy between TG and colistin, and our patient was successfully treated with this HDT-based combination. The third case emphasizes a 63-year-old patient with insulin-dependent diabetes, Child B cirrhosis, and a right double J ureteral stent who was hospitalized with a febrile cUTI. Urine and blood cultures were positive for carbapenem-resistant XDR Acinetobacter baumannii (susceptible to colistin and TG). Colistin was administered for only 96 hours because of stage II acute kidney injury, and we continued the treatment with HDT in monotherapy. The patient was discharged home, and no urinary tract infection relapse was seen for six months. Favorable clinical and microbiological outcomes were achieved with TG-based regimens in our cUTI cases. We highlight the role of antibiotic synergy determined by the in vitro E-test in two cases of MBL-producing XDR/PDR Klebsiella pneumoniae.

Third-Generation Tetracyclines: Current Knowledge and Therapeutic Potential

Tetracyclines constitute a unique class of antibiotic agents, widely prescribed for both community and hospital infections due to their broad spectrum of activity. Acting by disrupting protein synthesis through tight binding to the 30S ribosomal subunit, their interference is typically reversible, rendering them bacteriostatic in action. Resistance to tetracyclines has primarily been associated with changes in pump efflux or ribosomal protection mechanisms. To address this challenge, tetracycline molecules have been chemically modified, resulting in the development of third-generation tetracyclines. These novel tetracyclines offer significant advantages in treating infections, whether used alone or in combination therapies, especially in hospital settings. Beyond their conventional antimicrobial properties, research has highlighted their potential non-antibiotic properties, including their impact on immunomodulation and malignancy. This review will focus on third-generation tetracyclines, namely tigecycline, eravacycline, and omadacycline. We will delve into their mechanisms of action and resistance, while also evaluating their pros and cons over time. Additionally, we will explore their therapeutic potential, analyzing their primary indications of prescription, potential future uses, and non-antibiotic features. This review aims to provide valuable insights into the clinical applications of third-generation tetracyclines, thereby enhancing understanding and guiding optimal clinical use.