Pharmacokinetic and safety profiles of mesalazine enema in healthy Chinese subjects: A single- and multiple-dose study.

Mesalazine is a well-established treatment for ulcerative colitis by oral or topical administration. However, the pharmacokinetic (PK) and safety profiles of mesalazine administered by an enema has not been clarified in Chinese population. We conducted an open-label study to assess the PK and safety profiles of mesalazine in 11 healthy Chinese subjects after receiving mesalazine enema (1 g/100 mL) once daily for 7 consecutive days. Blood and urine samples were collected for assay of mesalazine and N-acetyl mesalazine by liquid chromatography-tandem mass spectrometry. The PK and safety data were summarized using descriptive statistics. The mean (standard deviation) maximum plasma concentration (Cmax), area under plasma drug concentration-time curve from time 0 to the last measurable plasma concentration time point (AUC0-t) and elimination half-life (t1/2) of mesalazine were 1007.64 (369.00) ng/mL, 9608.59 (3533.08) h·ng/mL and 3.33 (1.99) h, respectively after the first dose administration. In multiple-dose study, the estimated accumulation factor of mesalazine was 1.09. The cumulative urinary excretion rate of parent and major metabolite of mesalazine was 27.77%. After the last doe administration, 2.21% of the administered dose was excreted as mesalazine and 24.47% as N-acetyl mesalazine in urine within 24 h. Overall, 9 adverse events (AEs) were reported in 4 of the 11 subjects (36.4%), including oral ulcer, toothache, upper respiratory tract infection (1 each) and laboratory abnormalities (6 cases). All AEs were mild and recovered spontaneously without treatment, and were not considered as related to mesalazine. Mesalazine enema (1 g/100 mL) was safe and well tolerated in healthy Chinese subjects. These findings support further clinical trials in Chinese patients. Trial registration: This trial was registered to Chinese Clinical Trial Registry (ChiCTR) at https://www.chictr.org.cn (registration number: ChiCTR2300073148).

Tolerability and Pharmacokinetics of Contezolid at Therapeutic and Supratherapeutic Doses in Healthy Chinese Subjects, and Assessment of Contezolid Dosing Regimens Based on Pharmacokinetic/Pharmacodynamic Analysis.

PURPOSE: This study assessed the tolerability and pharmacokinetic (PK) properties of a new-generation oxazolidinone, contezolid (MRX-I), and its major inactive metabolite, M2, after single oral administrations of 800, 1200, and 1600 mg in the fed state, and compared the efficacy of 3 dosing regimens in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection based on PK/pharmacodynamic (PD) analysis. METHODS: A Phase I study at a single study center was conducted with 2 parts. In the first part, 20 healthy subjects received a single oral dose of 1200 or 1600 mg of contezolid or placebo in the fed state in a double-blind, placebo-controlled, dose-escalation tolerance study. In the second part of the study, 52 subjects received a single oral dose of 800 mg of contezolid in the fed state in a single-center, randomized, blinded, 4-period, crossover, thorough QT study. Noncompartmental analyses were used to evaluate the PK properties of contezolid and M2. Steady-state concentrations of contezolid following the 3 dosing regimens (800, 1200, and 1600 mg q12h) were simulated by employing a newly developed 2-compartmental PK model. The minimum inhibitory concentration (MIC) distributions of contezolid were analyzed in 178 Staphylococcus, Enterococcus, and Streptococcus clinical isolates. Monte Carlo simulations were conducted to predict the efficacy of the 3 dosing regimens to obtain probability of target attainment and cumulative fraction of response. FINDINGS: Single-dose oral administrations of 800, 1200, and 1600 mg of contezolid were well tolerated in healthy subjects in the fed state, and nonlinear PK was observed. The mean plasma exposures to M2 exceeded 17.3% of contezolid exposure in the 3 groups. Both MIC50 and MIC90 (MICs that inhibit the growth of 50% and 90% of microorganisms, respectively) of contezolid against MRSA were 1 mg/L with clinical isolates from China. PK/PD analysis and Monte Carlo simulations predicted that 800 mg q12h of oral contezolid would be efficacious against MRSA infection, with a MIC of ≤4 mg/L (probability of target attainment, >90%; cumulative fraction of response, >90%). IMPLICATIONS: Contezolid is a well-tolerated treatment option for MRSA infection, including at supratherapeutic doses up to 1600 mg. The regimen of 800 mg q12h could achieve efficacy in treating bacterial infection with MRSA. To our knowledge, this is the first PK study to predict that a dosing regimen of 800 mg q12h of oral contezolid is sufficient for treating MRSA infection, with a MIC of ≤4 mg/L. A Phase III study of this suggested dosing regimen is being conducted. Chinadrugtrials.org.cn identifier: CTR20161074.

Safety and efficacy of oral nemonoxacin versus levofloxacin in treatment of community-acquired pneumonia: A phase 3, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial.

BACKGROUND/PURPOSE: Nemonoxacin is a novel nonfluorinated quinolone with excellent in vitro activity against most pathogens in community-acquired pneumonia (CAP), especially Gram-positive isolates. The purpose of this study was to assess the efficacy and safety of nemonoxacin compared with levofloxacin in patients with CAP. METHODS: A phase 3, multicenter, randomized (2:1) controlled trial was conducted in adult CAP patients receiving nemonoxacin 500 mg or levofloxacin 500 mg orally once daily for 7-10 days. Clinical, microbiological response and adverse events were assessed. Non-inferiority was determined in terms of clinical cure rate of nemonoxacin compared with that of levofloxacin in a modified intention-to-treat (mITT) population. NCT registration number: NCT01529476. RESULTS: A total of 527 patients were randomized and treated with nemonoxacin (n = 356) or levofloxacin (n = 171). The clinical cure rate at test-of-cure visit was 94.3% (300/318) for nemonoxacin and 93.5% (143/153) for levofloxacin in the mITT population [difference (95% CI), 0.9% (-3.8%, 5.5%)]. The microbiological success rate was 92.1% (105/114) for nemonoxacin and 91.7% (55/60) for levofloxacin in the bacteriological mITT population [difference (95% CI), 0.4% (-8.1%, 9.0%)]. The incidence of adverse events (AEs) was comparable between nemonoxacin (33.1%, 118/356) and levofloxacin (33.3%, 57/171) (P > 0.05). CONCLUSION: Nemonoxacin 500 mg once daily for 7-10 days is as effective and safe as levofloxacin for treating adult CAP patients in terms of clinical cure rates, microbiological success rates, and safety profile. ClinicalTrials.gov identifier: NCT01529476.

[Monitoring of vancomycin serum concentrations and the evaluation of its safety and treatment outcomes in adult patients].

OBJECTIVE: To investigate the relationship between the serum level of vancomycin and its clinical efficacy as well as adverse reactions in adult patient so as to provide recommendations for clinical management. METHODS: An open observational research was performed from 1st July 2013 to 31st December 2017 in Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, which recruited the adult patients who were infected with Gram positive (G+) bacteria and treated with vancomycin. The initial dose was decided by the patient's creatinine clearance rate, and the treating dose was directed by the serum drug concentration and the patient's clinical response. By recording the associated clinical information (pathogen eradication, blood test results, adverse reactions, etc.), the clinical outcome and adverse reactions for vancomycin to treat G+ bacterial infections were analyzed. RESULTS: Eighty-nine cases who meet research standards were finally recruited, with 67.42% of male patients, and an average age of (50.5±17.9) years. The most common type of infection was bloodstream infection (61.80%), followed by low respiratory infection (17.98%). Infections caused by Staphylococcus aureus accounted for 39.33%. The bacterial eradication rate was 89.89% (80/89) and the total effective rate was 77.53% (69/89). The effective rate was 80.30% (53/66) with minimum inhibitory concentration (MIC) < 2 mg/L vs. 69.57% (16/23) with MIC ≥ 2 mg/L, the difference was not statistically significant (χ2 = 1.129, P = 0.288). The effective rate was 72.92% (35/48) with trough levels < 10 mg/L vs. 82.93% (34/41) with trough levels ≥ 10 mg/L, the difference was not statistically significant (χ2 = 1.272, P = 0.259). There were 4 cases of vancomycin associated nephrotoxicity, the incidence of nephrotoxicity was 4.49%, and the vancomycin serum trough levels were 17.22-28.53 mg/L. There were 33 cases of liver dysfunction, and elevated γ-glutamine transferase, alkaline phosphatase and aspartate aminotransferase were most common. There were 2 cases of neutropenia and 2 patients appeared rash during vancomycin period. CONCLUSIONS: Treatment outcomes were similar regardless of vancomycin MIC and serum trough level. The incidence of vancomycin associated nephrotoxicity rises apparently when serum trough level is over 15 mg/L. CLINICAL TRIAL REGISTRY: Chinese Clinical Trail Registry, ChiCTR-OPC-16007920.