Sequential emergence of colistin and rifampicin resistance in an OXA-72- producing outbreak strain of Acinetobacter baumannii

Objectives

This study reported a hospital outbreak due to an extensively drug-resistant (XDR) OXA-72-producing strain of Acinetobacter baumannii (A. baumannii).

复合三联抗结核药聚乳酸-羟基乙酸缓释微球的制备及体外释药特性

目的 :制备复合异烟肼(H)、利福平(R)、吡嗪酰胺(Z)的聚乳酸-羟基乙酸(HRZ/PLGA)缓释微球,观察其理化性质和体外缓释特性。方法:以PLGA(450mg)为载体,避光条件下称取H(40mg)、R(60mg)、Z(125mg),采用复乳-溶剂挥发法制备HRZ/PLGA缓释微球,应用扫描电镜观察微球的形态特征;应用高效液相色谱法(HPLC)测定其载药量、包封率;采用溶出法、HPLC于3h、6h、12h、1d、2d、3d、6d、9d、12d、15d、20d、25d、30d、40d、50d测定H、R、Z三种药物的浓度,观察其是否均大于10倍最低抑菌浓度(MIC),计算其日均释药率、累计释药率。结果:HRZ/PLGA微球在电镜下观察呈圆球形,平均粒径为10.3±4.7μm;H、R、Z三种药物的载药量分别为(18.02±0.36)%、(22.46±0.24)%、(21.68±0.37)%,包封率分别为(54.79±1.13)%、(72.35±0.39)%、(67.21±0.68)%;体外缓释试验显示微球缓释前12d左右,三种药物的累计缓释度均超过了50%,日均释药率分别为5.05%、4.89%、6.86%;第12天后三药的缓释基本趋于稳定,日均释药率分别为0.17%、0.26%、0.16%;三种药物缓释到50d时均大于10倍MIC。结论:HRZ/PLGA微球具有优良的载药及药物缓释效果,是一种理想的复合抗结核药物缓释系统。     

抗结核药缓释涂层在兔脊柱结核模型体内的抗结核性能及组织相容性观察

目的:观察抗结核药异烟肼(H)、利福平(R)、吡嗪酰胺(Z)缓释涂层在兔脊柱结核模型体内的抗结核性能及组织相容性。方法:选取健康新西兰兔构建L4/5脊柱结核模型,将建模成功的60只模型兔随机分为A、B、C三组,每组20只,其中A组(实验组)病灶清除术后植入包裹HRZ缓释涂层的自体髂骨;B组(对照组)病灶清除术后植入包裹空白涂层的自体髂骨;C组(空白对照组)病灶清除术后单纯植入自体髂骨。术后观察实验兔一般状况及伤口情况;造模前1d、病灶清除术前及术后1d、3d、7d、14d、28d、56d、84d、112d进行血沉(ESR)、C反应蛋白(CRP)检测;术前以及术后14d、28d、56d进行肝肾功能检测;术后28d时A组随机处死5只兔,取心脏、肝脏、脊髓、脾脏及肾脏组织制作病理切片观察;术后56d行脊柱X线片检查后,每组随机处死5只兔在植骨部位局部取材进行骨-材料界面组织病理学观察。结果:术后B组1只兔切口感染,C组1只兔死亡、1只兔截瘫,其余兔术后一般状况良好。三组造模前和手术前的ESR和CRP均无统计学差异(P0.05);三组手术前的ESR和CRP均较造模前显著性升高(P0.01)。三组术后1d时ESR和CRP均较术前显著性升高,3d时CRP达到峰值,7d时ESR达到高峰,此后逐渐下降;A组至术后56d时CRP降至造模前水平,84d时ESR降至造模前水平;B、C组至112d时CRP和ESR均仍显著性高于造模前水平(P0.05)。A组术后7d、56d、84d及112d的ESR和CRP均低于同时间点B、C组(P0.05),B组与C组同时间点无显著性差异(P0.05)。三组间术前和术后14d、28d、56d的肝、肾功能指标比较均无统计学差异(P0.05);三组术后14d、28d、56d的肝、肾功能指标与术前比较均无统计学差异(P0.05)。术后28d时A组心脏、肝脏、脾脏、脊髓及肾脏组织未见器质性改变及组织损伤征象。术后56d时A组植骨融合情况优于B组及C组(P0.05),骨-材料界面组织病理切片骨小梁面积显著性高于B组及C组(P0.01)。结论:HRZ缓释涂层在兔体内具有优良的抗结核性能和组织相容性。     

Relative Bioavailability of Rifampicin in Four Chinese Fixed-dose Combinations Compared with Rifampicin in Free Combinations

Background:

Decreases in the bioavailability of rifampicin (RFP) can lead to the development of drug resistance and treatment failure. Therefore, we investigated the relative bioavailability of RFP from one four-drug fixed-dose combination (FDC; formulation A) and three two-drug FDCs (formulations B, C, and D) used in China, compared with RFP in free combinations of these drugs (reference), in healthy volunteers.

Methods:

Eighteen and twenty healthy Chinese male volunteers participated in two open-label, randomized two-period crossover (formulations A and C) or one three-period crossover (formulations B and D) study, respectively. The washout period between treatments was 7 days. Bioequivalence was assessed based on 90% confidence intervals, according to two one-sided t-tests. All analyses were done with DAS 3.1.5 (Mathematical Pharmacology Professional Committee of China, Shanghai, China).

Results:

Mean pharmacokinetic parameter values of RFP obtained for formulations A, B, C, and D products were 11.42 ± 3.41 μg/ml, 7.86 ± 5.78 μg/ml, 13.05 ± 6.80 μg/ml, and 16.18 ± 3.87 μg/ml, respectively, for peak plasma concentration (C_max), 91.43 ± 30.82 μg·h⁻¹ ·ml⁻¹, 55.49 ± 37.58 μg·h⁻¹ ·ml⁻¹, 96.50 ± 47.24 μg·h⁻¹ ·ml⁻¹, 101.47 ± 33.07 μg·h⁻¹ ·ml⁻¹, respectively, for area under the concentration-time curve (AUC_{0−24 h}).

Conclusions:

Although the concentrations of RFP for formulations A, C, and D were within the reported acceptable therapeutic range, only formulation A was bioequivalent to the reference product. The three two-drug FDCs (formulations B, C and D) displayed inferior RFP bioavailability compared with the reference (Chinese Clinical Trials registration number: ChiCTR-TTRCC-12002451).     

用利福平和强力霉素治疗急性期和亚急性期布鲁氏菌病42例疗效报告

本文报告用利福平和强力霉素治疗急性期和亚急性期布鲁氏菌病42例,治愈41例,治愈率97.62％,基本治愈1例,占2.38％。经对全部治愈病人在6个月、12个月时两次随访结果,无一例复发。与其他治疗方法疗效对比,证明该法有用药方便,疗程短,副作用小,疗效高,复发率低等优点。     

主要抗结核药物肝脏毒性的动物实验研究

目的探讨肝脏脂质过氧化反应和肝药酶活性改变与抗结核药物肝毒性的关系.方法健康成年SD大鼠56只,随机分为7组：INH（isoniazid,H）组、RFP（rifampicin,R）组、PZA（pyrazinamide,Z）组、HR组、RZ组、HRZ组和生理盐水对照组.分别灌药10 d后处死大鼠,取肝脏切片,电子显微镜下观察肝脏病理变化,制备肝匀浆测定MDA（Maleic Dialdehyde）、SOD（Superoxide Dismutase）、GSH（reduced glutathione）和P450含量.结果各实验组MDA和P450均有不同程度升高,SOD和GSH有不同程度降低,肝脏病理变化与脂质过氧化反应、肝药酶有相关性.结论异烟肼、利福平、吡嗪酰胺均可引起大鼠的脂质过氧化指标的改变及肝脏细胞的病理损害,多种药物联用比单用改变明显;抗结核药物肝脏毒性与脂质过氧化反应程度关系密切,吡嗪酰胺组比其他单用药组肝脏毒性大.利福平有明显肝药酶诱导活性.     

利福平致急性肾功能衰竭伴急性溶血性贫血及肝功能异常1例文献分析

目的为临床及时发现、诊断、治疗利福平所致急性肾功能衰竭提供参考。方法对我院利福平致急性肾功能衰竭1例及国内已经报道的临床资料进行综合分析。结果综合我院1例利福平致急性肾功能衰竭及文献报道共44例患者的一般资料、给药方法、发生时间、处理及结果,其中32例既往有使用利福平史,在服药后15分钟至50天发病,积极治疗后可缓解。结论在使用利福平的过程中应密切监测肾功能,及时发现利福平所致的急性肾功能衰竭。     

A new respirable form of rifampicin

The aim of this research was to investigate a novel dry powder formulation of rifampicin (RF) that presents an improved lung deposition profile by means of a polymorphic transformation into a flake-like crystal hydrate. Rifampicin dihydrate (RFDH) was prepared by recrystallization of RF in anhydrous ethanol. A control formulation, amorphous RF (RFAM) was prepared by spray drying. The physicochemical properties of the RFDH and the RFAM were characterized. Aerosol performances of RFDH and RFAM were studied with two dry powder inhalers (DPIs), an Aerolizer® and a Handihaler®, using a Next Generation Impactor (NGI). The RFDH powder was successfully prepared using simple recrystallization process and had a MMAD of 2.2 μm. The RFDH powders were characterized as having a very thin flaky structure; this unique morphology provided improved aerosolization properties with a decreased device dependency upon aerosolization. The flaky morphology of RFDH resulted in a reduced agglomeration tendency than that of spherical RFAM particles. The maximum fine particle fraction (FPF_TD) of 68% for the RFDH was achieved with the Aerolizer® device. Significant chemical degradation was not observed from the RFDH, while the RFAM showed significant chemical degradation at 9 months. The excipient-free formulation of the RFDH offers the benefit of delivering a maximum potency formulation, of the antibiotic, directly to the site of infection, the lung.     

Design and Study of Rifampicin Oral Controlled Release Formulations

Oral controlled release formulations of rifampicin have been developed by using hydroxypropyl methylcellulose polymer at different ratios. From in vitro release data, we found that the release was extended with an increase of polymer proportion from 20% to 40%. However, increase in polymer beyond 40% resulted in no significant change in the release rate. There was a distinct difference in the release rate and release character due to variation in the compression force. The release kinetics were analyzed using Ritger and Peppas exponential equation. Stability studies at ambient storage conditions for 1 year showed that formulations were stable.