Massive acetylcysteine overdose associated with cerebral edema and seizures

Context. Acetylcysteine is a safe and effective treatment for the prevention of hepatic injury due to acetaminophen poisoning. While dosing errors are common, in most cases, overdoses produce minimal clinical effects. Case report. We describe a patient who received 150 g of IV acetylcysteine over 32 h when the clinician ordered the infusion doses be administered as an hourly dose (100 mg/kg/h) rather than administered over the infusion duration (100 mg/kg over 16 h). After approximately 28 h of receiving 100 mg/kg/h, the patient developed delirium, and seizures that progressed to cerebral edema, uncal herniation, and ultimately severe brain injury. No other cause for her symptoms was identified during an extensive workup. Discussion. This case suggests that massive IV acetylcysteine overdose can cause cerebral dysfunction and life-threatening effects.     

Predicting the requirement for N-acetylcysteine in paracetamol poisoning from reported dose

Abstract

Context. There is contention over whether reported dose correlates with toxicity in paracetamol poisoning and risk assessment is currently based on serum paracetamol concentration compared to a nomogram, irrespective of reported dose. Objective. To determine if reported dose predicts the need for N-acetylcysteine (NAC). Methods. Data were taken from paracetamol overdoses presenting to a tertiary toxicology service. Age, sex, reported dose, ingestion time, timed paracetamol concentrations between 4 and 16 h, hepatotoxicity (peak alanine transaminase > 1000 U/L) and treatment (single dose-activated charcoal [SDAC] and NAC) were analysed. Data were analysed within a repeated measures logistic regression framework using NONMEM (ver 7.2). The primary outcome was administration of NAC, which was determined based on a serum paracetamol concentration greater than the nomogram line. Result.: There were 1571 admissions in 1303 patients, with a median age of 27 years (12–96 years) and 1140 (73%) were females. The median dose was 10 g (1–100 g). The paracetamol concentration was above the nomogram line in 337 of 1571 (22%) patients. Patients presenting later (first paracetamol concentration between 7 and 16 h post-overdose) compared to those presenting earlier (4–7 h post-overdose) were more likely to have hepatotoxicity (5.5% vs. 0.4%; p < 0.0001), have a toxic paracetamol concentration (34% vs. 18%; p < 0.0001) and receive NAC (48% vs. 23%; p < 0.0001). SDAC reduced the probability of the paracetamol concentration being above the nomogram. Based on SDAC not being administered there was a 5% probability of requiring NAC at a dose of 6–9 g, a 10% chance of requiring NAC at a dose of 13–16 g, a 50% chance of requiring NAC at a dose of 30–34 g and a 90% chance for needing NAC at 48–50 g. Conclusion. Reported dose was a good predictor of a toxic paracetamol concentration and SDAC reduced the probability of the concentration being above the nomogram. These predictions may assist in determining which patients could be started on NAC immediately.     

N-乙酰半胱氨酸对体外循环诱发犬肺损伤的影响

目的 探讨N-乙酰半胱氨酸对体外循环(CPB)诱发犬肺损伤的影响.方法 成年犬36只,雌雄不拘,体重15 ～ 16 kg,采用随机数字表法,将其随机分为2组(n=18):CPB组(C组)和N-乙酰半胱氨酸组(N组).右锁骨下动脉和右心房分别插管,制备CPB模型,N组于CPB前即刻静脉注射N-乙酰半胱氨酸150mg/kg,然后以20 mg·kg-1·h-1速率静脉输注至CPB结束后60 min;C组给予等容量生理盐水.分别于CPB前、CPB结束后30、60 min时采集动脉血样,进行动脉血气分析,计算呼吸指数和氧合指数;然后处死动物,取肺组织,测定MDA含量、SOD活性和转化生长因子-β1( TGF-β1) mRNA表达;光镜和电镜下观察肺组织病理学结果.结果 与C组比较,N组呼吸指数和肺组织MDA含量降低,氧合指数和肺组织SOD活性升高,TGF-β1 mRNA表达下调(P＜0.05或0.01),肺组织病理学损伤程度明显减轻.结论 N-乙酰半胱氨酸可减轻CPB诱发犬肺损伤,其机制与减轻脂质过氧化反应,下调肺组织TGF-β1表达有关.     

Protective Effect of N‐Acetylcysteine Against Arsenic‐Induced Depletion In Vivo of Carbohydrate

N‐acetylcysteine (NAC), a synthetic aminothiol, possesses antioxidative and cytoprotective properties. The present study evaluates the effect of NAC supplementation on arsenic‐induced depletion in vivo of carbohydrates. Arsenic (as sodium arsenite) treatment (i.p.) of male Wistar rats (120–140 g b.w.) at a dose of 5.55 mg/kg body weight (35% of LD₅₀) per day for a period of 30 days produced a significant decrease in blood glucose level (hypoglycemia) and a fall in liver glycogen and pyruvic acid contents. The free amino acid nitrogen content of liver increased while that of kidney decreased after arsenic treatment. Arsenic also enhanced the liver lactate dehydrogenase activity whereas glucose 6‐phosphatase activity in both liver and kidney decreased significantly following arsenic treatment. Transaminase activities in liver and kidney were not significantly altered except the glutamate–pyruvate transaminase activity that was reduced in kidney after arsenic treatment. Oral administration of NAC (163.2 mg/kg/day) for last 7 days of treatment prevented the arsenic‐induced hypoglycemia and glycogenolytic effects to an appreciable extent. There was also recovery of liver pyruvic acid as well as liver and kidney free amino acid nitrogen content after NAC supplementation. Arsenic‐induced alteration of glucose 6‐phosphatase activity in both liver and kidney was also counteracted by NAC. It is suggested that carbohydrate depletion in vivo due to exposure to arsenic can be counteracted by NAC supplementation.     

N-乙酰半胱氨酸对碘海醇诱导肾小管上皮细胞损伤的保护作用

目的 探讨N-乙酰半胱氨酸（NAC）对碘海醇引起人肾小管上皮细胞（HK-2）损伤的保护作用及机制。 方法 将体外培养的HK-2细胞分为4组：对照组、碘海醇组、NAC组、NAC预处理＋碘海醇共作用组。用细胞增殖/毒性检测法（CCK-8）测定细胞存活率;核染色、AnnexinⅤ-FITC/PI双染法检测细胞凋亡;二氯二氢荧光素双醋酸盐（DCFH-DA）荧光结合流式细胞法检测细胞内活性氧（ROS）的产生;免疫荧光（IF）、Western印迹法检测相关信号转导途径。 结果 碘海醇呈剂量和时间依赖性诱导HK-2细胞凋亡,降低细胞存活率。碘海醇使细胞内ROS升高至对照组的1.3倍。NAC（5、10、15 mmol/L）预处理与碘海醇共作用后, HK-2细胞存活率分别增至104%、118%、130%,与碘海醇组（63%）差异有统计学意义（P < 0.05）;凋亡率分别降为13.51%、13.46%、12.23%,与碘海醇组（24.41%）差异亦有统计学意义（P < 0.05）;活性氧分别降为对照组的1.05、0.93、0.86倍,与碘海醇组（对照组的1.3倍）差异亦有统计学意义（P < 0.05）。碘海醇作用于HK-2细胞,引起p53磷酸化,上调Bax,下调Bcl-2的表达,促进线粒体内细胞色素C（CytC）释放到胞质,进而引起半胱天冬氨酸蛋白酶（caspase）-3活化,导致细胞凋亡。NAC降低细胞内ROS浓度,下调Bax表达,上调Bcl-2表达,减少caspase-3活化,从而减轻细胞损伤。 结论 碘海醇增加细胞内ROS生成,引起p53磷酸化,进而影响Bcl-2家族蛋白表达,促进CytC从线粒体释放和激活caspase-3信号通路,导致细胞凋亡。NAC通过清除氧自由基,降低细胞内ROS浓度,进而减轻碘海醇诱导的氧化应激所致细胞损伤及凋亡。     

乙酰半胱氨酸联合莫西沙星治疗慢性阻塞性肺疾病急性加重期的临床研究

目的探讨乙酰半胱氨酸颗粒联合莫西沙星治疗慢性阻塞性肺疾病急性加重期(AECOPD)的临床效果。方法选取2017年6月—2020年6月天津市第五中心医院(北京大学滨海医院)收治的86例AECOPD患者,使用随机数字表法分成对照组(n=43)和治疗组(n=43)。对照组静脉滴注盐酸莫西沙星注射液,每次将0.4 g加入5%葡萄糖注射液250 m L中充分稀释后给药,1次/d。治疗组在对照组基础上口服乙酰半胱氨酸颗粒,1包/次,3次/d。两组均连续治疗14 d。观察两组临床疗效及患者典型呼吸道症状和体征的缓解时间。并比较治疗前后两组血清白三烯B4(LTB4)、白细胞介素-8(IL-8)、8异前列腺素F2α(8-iso-PGF2α)、前白蛋白(PA)、丙二醛(MDA)水平。结果治疗后,治疗组总有效率为95.3%,显著高于对照组79.1%(P0.05)。治疗后,治疗组咳嗽、咳痰、喘息和肺部哮鸣音缓解时间均显著短于对照组(P0.05)。治疗后,两组血清LTB4、IL-8、8-iso-PGF2α及MDA水平均较本组治疗前显著下降(P0.05),血清PA水平则均显著升高(P0.05);且治疗后,治疗组血清学指标改善优于对照组(P0.05)。结论乙酰半胱氨酸颗粒联合莫西沙星对AECOPD患者具有确切的临床疗效,能安全有效且迅速地稳定患者病情,改善肺功能,并可显著减轻机体炎症反应、降低氧化应激损伤,值得临床推广应用。     

Efficacy of Hepatoprotective Agents With or Without Antiviral Drugs on Liver Function and Fibrosis in Patients With Hepatitis B: A Meta-Analysis

Context:

To systematically evaluate the effects of hepatoprotective agents, when delivered either alone or in combination with other antiviral or non-antiviral drugs in patients with hepatitis B and hepatic fibrosis.

Objectives:

The current randomized controlled clinical trials aimed to evaluate the efficacy of combinations of antiviral and non-antiviral hepatoprotective agents on indexes of liver function and liver fibrosis in patients with hepatitis B.

Data Sources:

Published literatures in Chinese and English on hepatoprotective treatment strategies for chronic hepatitis B and liver fibrosis were searched in three databases and randomized controlled clinical trials were selected.

Study Selection:

Data were extracted according to a variety of inclusion and exclusion criteria. Meta-analysis was employed to analyze the data.

Results:

A total of 22 randomized controlled trials encompassing 1,714 cases were considered in the meta-analysis. The obtained results indicated that the combination of antiviral drug and hepatoprotective agent was better than antiviral drug alone to improve liver function. Similarly, regarding liver fibrosis, using two different hepatoprotective agents was better than using one agent. The normalization rates of Aminotransferase (ALT) and total Bilirubin (TBil) were improved 25.7% by two hepatoprotective agents compared to the single agent. Acetylcysteine was superior to ursodeoxycholic acid or silibinin to reduce ALT. Ursodeoxycholic acid was superior to acetylcysteine or silibinin to reduce TBIL.

Conclusions:

Hepatoprotective agents combined with antiviral drugs can significantly improve liver function and liver fibrosis parameters in patients with hepatitis B.     

N-乙酰半胱氨酸通过调控细胞周期蛋白加重乳鼠心肌细胞的衰老

目的 了解N-乙酰半胱氨酸(NAC)对心肌细胞衰老的影响及其机制.方法 将培养的SD乳鼠心肌细胞随机分为1 d组、5 d组、10 d组、1 d+NAC(1 mmol/L)组、5 d+NAC(1 mmol/L)组、10 d+NAC(1 mmol/L)组.采用流式细胞仪检测细胞周期.采用实时定量PCR与Western blot等方法检测p16INK4a、p21WAF1及Rb基因mRNA与蛋白水平表达的变化.采用β-半乳糖苷酶原位染色试剂盒检测β-半乳糖苷酶活性的改变.结果 5 d+NAC(1 mmol/L)组、10 d+NAC(1 mmol/L)组G0/G1期细胞数分别为86.71％、91.23％,显著高于单纯5 d组、10 d组的82.13％、87.97％,P均＜0.01.5 d+NAC(1 mmol/L)组、10 d+NAC(1 mmol/L)组p16INK4a基因mRNA拷贝数与β-actin比值分别为0.48、1.31,显著高于单纯5 d组、10 d组的0.35、0.74,P＜0.05与＜0.01.p16INK4a基因蛋白表达与B-actin比值分别为0.96、1.12,显著高于单纯5 d组、10 d组的0.31、0.49,P均＜0.01.5 d+NAC(1 mmol/L)组、10 d+NAC(1 mmol/L)组p21WAF1基因mRNA拷贝数与β-actin比值分别为1.25、2.13,显著高于单纯5 d组、10 d组的0.96、1.24,P＜0.05与＜0.01.p21WAF1基因蛋白表达与β-actin比值分别为1.22、2.16,显著高于单纯5 d组、10 d组的0.71、1.13,P均＜0.01.5 d+NAC(1 mmol/L)组、10 d+NAC(1 mmol/L)组Rb基因mRNA拷贝数与β-actin比值分别为0.18、0.09,显著高于单纯5 d组、10 d组的0.35、0.17,P均＜0.01.Rb基因蛋白表达与β-actin比值分别为0.84、0.33,显著低于单纯5 d组、10 d组的1.47、0.81,P＜0.05与＜0.01.5 d+NAC(1 mmol/L)组、10 d+NAC(1 mmol/L)组β-半乳糖苷酶活性分别为29.71％、79.31％,显著高于单纯5 d组、10 d组的17.46％、58.24％,P均＜0.05.结论 NAC可通过增加p16INK4a与p21WAF1基因表达,抑制Rb蛋白的磷酸化,从而促使心肌细胞周期阻滞于G0/G1期,β-半乳糖苷酶活性明显增强,加重细胞衰老.