这些老药的新功效,你知道吗(五)

<正>(接上期)十六、活性炭的多种用途活性炭具有多孔性及巨大的吸附作用,因此有着广泛的用途:在制药工业中可以用作吸附杂质,提高制剂质量。在注射剂制备中加活性炭可以吸附热原,增加药物安全性,也可以脱色,使产品更美观,但更重要的是其临床方面的用途:1.解毒:活性炭是抢救食物或药物中毒时常用药,可以吸附毒物,     

活性炭吸附细菌内毒素的作用研究

目的:研究活性炭对细菌内毒素的吸附作用以及有机溶剂对细菌内毒素的解吸附作用。方法:采用鲎试剂法研究不同的前处理方式、温度、活性炭用量和处理时间对活性炭吸附细菌内毒素作用的影响;采用不同的有机溶剂及处理时间研究对已吸附内毒素的解吸附效果。结果:高温烘烤以及加入0.5mol·L-1NaOH2种方式处理活性炭去除内毒素的作用相当;在活性炭用量为1.5%、吸附时间为12min时吸附效果较好;室温与37℃条件下吸附效果相当;以75%乙醇为解吸附剂、剧烈振荡8min后的内毒素回收效果较佳。结论:合理选用合适的条件有助于活性炭对内毒素的吸附以及有机溶剂回收内毒素。     

活性炭的临床应用进展

活性炭具有巨大的比表面积、发达的孔隙结构、独特的化学稳定性,是一种优良的吸附剂。其既可以吸附有毒物质,用于中毒患者的抢救,又可以吸附药物。纳米级活性炭具有黑染作用,可在术中示踪与指导淋巴结清扫,提高淋巴结的切斜效率,临床疗效较好。     

活性炭的临床应用进展

活性炭具有巨大的比表面积、发达的孔隙结构、独特的化学稳定性,是一种优良的吸附剂。其既可以吸附有毒物质,用于中毒患者的抢救,又可以吸附药物。纳米级活性炭具有黑染作用,可在术中示踪与指导淋巴结清扫,提高淋巴结的切斜效率,临床疗效较好。     

急性百草枯中毒的综合治疗

目的探讨急性百草枯中毒综合治疗的疗效。方法对我院的21例百草枯中毒患者进行回顾性分析,对患者给予了综合性治疗,包括洗胃、活性炭吸附、导泻、抗氧化、激素冲击、免疫抑制剂这些常规治疗外,并予血必净注射液解毒、血液灌流联合血液滤过清除毒素治疗。结果 21例百草枯中毒患者中,11例存活,6例死亡,4例自动出院,死亡率为47.6%。结论急性百草枯中毒患者尽早开展综合治疗,可提高抢救成功率;血液灌流联合血液滤过治疗能降低急性百草枯中毒的死亡率。     

子母囊型人工细胞的研究

子母囊型人工细胞是一种吸附型的人工肝肾解毒剂,本文报道了它的微型包囊技术制备的新工艺。以交联明胶为膜材料制成的球状子母囊型人工细胞,粒度为1.5～2.5mm,对血液有良好的相容性。子母囊活性炭通过静态等温及动态吸附试验,证明对氯丙嗪等有很好的吸附效果,并初步应用于临床,对肾衰竭尿毒症患者及安眠药中毒病例有良好的解毒效果。     

人工肝支持系统治疗慢性重型肝炎肝肾综合征疗效观察及护理

分子吸附再循环系统（MARS）是一种新的人工肝支持系统,其性能特点是在有效清除水溶性中、水分子毒素的同时,还可以选择性的清除亲脂性及血浆白蛋白相结合毒素分子,并保留血液中有用的重要营养物质和蛋白质。近年来,国内外在治疗重型肝炎及其并发症中有较多的临床应用。我院应用MARS人工肝治疗慢性重型肝炎肝肾综合征22例,现将治疗方法及护理报告如下。     

解毒酶兴诊断酶的临床应用

酶制品根据其临床应用,具有解除体内存留毒素的称为解毒酶类,用于诊断疾病的则称診断酶类。它们在作用上,多属于水解酶和氧化还原酶之列。解毒酶常用者有:青霉素酶、组织胺酶、过氧化氢酶。诊断酶常用者为:脲酶、葡萄糖氧化酶等。今简要分述如下:     

淋巴靶向制剂——吸附抗癌药毫微粒活性炭的研究进展

目的介绍新型淋巴靶向制剂———吸附抗癌药毫微粒活性炭的研究进展。方法依据近年来的文献 ,对活性炭的制备工艺及体内外性质等方面进行了综述。结果活性炭具有很强的吸附功能 ,普通市售活性炭仅用作脱色、吸附热原与除味等。以微粒球磨机为粉碎器械 ,可加工制备粒径达1 0 0nm左右的纳米炭微粒 ,具有优越的淋巴趋向性。结论吸附抗癌药毫微粒活性炭在临床治疗癌症方面具有良好的运用前景     

活性炭对药物的影响及其解毒的应用

活性炭(Activated Charcoal)是一种常用的吸附剂,在医药学上很早就有应用。近二十年来,经口服活性炭对药物体内过程影响的研究,发现活性炭不仅可在胃肠道吸附某些药物分子,降低药物的吸收,还可增加体内药物的消除。根据这种论点,用口服活性炭法解救某些药物中毒,在临床上     

Pharmacokinetics of digoxin cross-reacting substances in patients with acute yellow Oleander (Thevetia peruviana) poisoning, including the effect of activated charcoal

Intentional self-poisonings with seeds from the yellow oleander tree (Thevetia peruviana) are widely reported. Activated charcoal has been suggested to benefit patients with yellow oleander poisoning by reducing absorption and/or facilitating elimination. Two recent randomized controlled trials (RCTs) assessing the efficacy of activated charcoal yielded conflicting outcomes in terms of mortality. The effect of activated charcoal on the pharmacokinetics of Thevetia cardenolides has not been assessed. This information may be useful for determining whether further studies are necessary. Serial blood samples were obtained from patients enrolled in an RCT assessing the relative efficacy of single-dose and multiple-dose activated charcoal (SDAC and MDAC, respectively) compared with no activated charcoal (NoAC). The concentration of Thevetia cardenolides was estimated with a digoxin immunoassay. The effect of activated charcoal on cardenolide pharmacokinetics was compared between treatment groups by determining the area under the curve for each patient in the 24 hours following admission, the 24-hour mean residence time, and regression lines obtained from serial concentration points, adjusted for exposure. Erratic and prolonged absorption patterns were noted in each patient group. The apparent terminal half-life was highly variable, with a median time of 42.9 hours. There was a reduction in 24-hour mean residence time and in the apparent terminal half-life estimated from linear regression in patients administered activated charcoal, versus the control group (NoAC). This effect was approximately equal in patients administered MDAC or SDAC. Activated charcoal appears to favorably influence the pharmacokinetic profile of Thevetia cardenolides in patients with acute self-poisoning and may have clinical benefits. Given the conflicting clinical outcomes noted in previous RCTs, these mechanistic data support the need for further studies to determine whether a particular subgroup of patients (eg, those presenting soon after poisoning) will benefit from activated charcoal.     

Position statement and practice guidelines on the use of multi-dose activated charcoal in the treatment of acute poisoning. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the Boards of the two societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. Although many studies in animals and volunteers have demonstrated that multiple-dose activated charcoal increases drug elimination significantly, this therapy has not yet been shown in a controlled study in poisoned patients to reduce morbidity and mortality. Further studies are required to establish its role and the optimal dosage regimen of charcoal to be administered. Based on experimental and clinical studies, multiple-dose activated charcoal should be considered only if a patient has ingested a life-threatening amount of carbamazepine, dapsone, phenobarbital, quinine, or theophylline. With all of these drugs there are data to confirm enhanced elimination, though no controlled studies have demonstrated clinical benefit. Although volunteer studies have demonstrated that multiple-dose activated charcoal increases the elimination of amitriptyline, dextropropoxyphene, digitoxin, digoxin, disopyramide, nadolol, phenylbutazone, phenytoin, piroxicam, and sotalol, there are insufficient clinical data to support or exclude the use of this therapy. The use of multiple-dose charcoal in salicylate poisoning is controversial. One animal study and 2 of 4 volunteer studies did not demonstrate increased salicylate clearance with multiple-dose charcoal therapy. Data in poisoned patients are insufficient presently to recommend the use of multiple-dose charcoal therapy for salicylate poisoning. Multiple-dose activated charcoal did not increase the elimination of astemizole, chlorpropamide, doxepin, imipramine, meprobamate, methotrexate, phenytoin, sodium valproate, tobramycin, and vancomycin in experimental and/or clinical studies. Unless a patient has an intact or protected airway, the administration of multiple-dose activated charcoal is contraindicated. It should not be used in the presence of an intestinal obstruction. The need for concurrent administration of cathartics remains unproven and is not recommended. In particular, cathartics should not be administered to young children because of the propensity of laxatives to cause fluid and electrolyte imbalance. In conclusion, based on experimental and clinical studies, multiple-dose activated charcoal should be considered only if a patient has ingested a life-threatening amount of carbamazepine, dapsone, phenobarbital, quinine, or theophylline.     

Variability of Mitomycin C Adsorption by Activated Charcoal

A saline suspension of mitomycin C adsorbed on activated charcoal and administered intraperitoneally has been reported to be safe and effective in the treatment of gastric carcinoma. Activated charcoal specifically targets tumour and lymph-node tissues and the sustained higher local drug concentration is thought to be beneficial. The charcoal particles used in these suspensions have varied in size from > 147 μm to < 20 nm in diameter, but no data have been published to show how this might affect drug adsorption and delivery. Any variability in drug adsorption could pose a serious clinical risk for drugs with a narrow therapeutic index. We have, therefore, investigated the adsorption of mitomycin C on activated charcoal in-vitro. Activated charcoal was ground and sieved to yield four size-fractions between 180 and 53 μm. Adsorption isotherms (n ≥ 3) were constructed and applied to the Freundlich model with 0–100 μg mL^?1 mitomycin C measured by HPLC with detection at 365 nm. Adsorption of mitomycin C by activated charcoal varied by a factor of three under identical conditions at room temperature (21°C) and at 37°C. The specific adsorption (μg mitomycin C (mg activated charcoal)^?1) was generally higher at 37°C than at room temperature. The variability of mitomycin C adsorption was greatly reduced by addition of the surface-active agent polyvinylpyrollidone, used to determine that adsorption of mitomycin C was independent of activated charcoal particle size. The characteristics of adsorption of mitomycin C by activated charcoal are complex and should be thoroughly investigated to discover the critical controlling factors before submitting the suspensions for further clinical evaluation.     

In vitro study of boric acid and activated charcoal

An in-vitro study utilizing a titration assay was performed to evaluate the degree of adsorption of one gram of boric acid by 7.5 g, 15.0 g and 30.0 g of activated charcoal. The mean percentage adsorbed was 5.7 +/- 1.6% for 7.5 g of activated charcoal, 17.6 +/- 3.5% for 15.0 g of activated charcoal and 38.6 +/- 6.3% for 30.0 g of activated charcoal. Analysis of variance showed a significant difference from the control (no activated charcoal) for the 15.0 and 30.0 g samples (p less than 0.05). Although binding of boric acid by activated charcoal increased as the proportion of activated charcoal to boric acid increased, this finding is not clinically significant since the amount of activated charcoal required for 38% adsorption is 30 times the amount of boric acid ingested. Considering the toxic and potentially fatal doses of boric acid in children (5 g) and adults (20 g), doses of activated charcoal of greater than 150 g in children or 600 g in adults would be impractical for the clinical situation.     

The extent of drug-drug interaction between amlodipine and activated charcoal is attenuated by food intake in rats

Activated charcoal decreases gastrointestinal absorption of concomitantly administered drugs. The absorption of amlodipine (AML) was reported as almost completely attenuated by 25 g of activated charcoal under a fasted condition, but not affected by 2 g of activated charcoal under a fed condition. However, it is not clear whether this difference resulted from the food intake or the dose of activated charcoal. The aim of this study was to quantitatively evaluate the effect of food intake on drug interactions caused by adsorption to activated charcoal in the gastrointestinal tract in rats. The rats were orally administered 0.08 mg/kg of AML, with or without 33 mg/kg of activated charcoal, under the fasted or fed condition and the plasma concentration profiles of AML were monitored. For the fed group, the standard breakfast used in clinical studies was smashed and administered at a dose of 11 g/kg. The AUC value of AML under the fasted condition was significantly decreased to 24.8% by coadministration of activated charcoal. On the other hand, activated charcoal moderately decreased the AUC value of AML to 74.8% under the fed condition. These results suggest that the extent of drug interactions caused by activated charcoal is attenuated by food intake.     

Activated charcoal reduces the need for N-acetylcysteine treatment after acetaminophen (paracetamol) overdose

BACKGROUND: The evidence for efficacy of gastric lavage and activated charcoal for gastrointestinal decontamination in poisoning has relied entirely on volunteer studies and/or pharmacokinetic studies and evidence for any clinical benefits or resource savings is lacking. AIM OF STUDY: To investigate the value of gastrointestinal decontamination using gastric lavage and/or activated charcoal in acetaminophen (paracetamol) poisoning. PATIENTS AND METHODS: We analyzed a series of 981 consecutive acetaminophen poisonings. These patients were treated with gastric lavage and activated charcoal, activated charcoal alone, or no gastrointestinal decontamination. The decision as to which treatment was received was determined by patient cooperation, the treating physician, coingested drugs, and time to presentation after the overdose. RESULTS: Of 981 patients admitted over 10 years, 10% (100) had serum concentrations of acetaminophen that indicated a probable or high risk of hepatotoxicity. The risk of toxic concentrations for patients ingesting less than 10 g of acetaminophen was very low. In patients presenting within 24 hours, who had ingested 10 g or more, those who had been given activated charcoal were significantly less likely to have probable or high risk concentrations (Odds ratio 0.36, 95% CI 0.23-0.58, p < 0.0001). Gastric lavage, in addition to activated charcoal, did not further decrease the risk (Odds ratio 1.12, 95% CI 0.57-2.20, p = 0.86). CONCLUSIONS: Toxic concentrations of serum acetaminophen (paracetamol) are uncommon in patients ingesting less than 10 g. In those ingesting more, activated charcoal appears to reduce the number of patients who achieve toxic acetaminophen concentrations and thus may reduce the need for treatment and hospital stay.     

Interaction between N-acetylcysteine and activated charcoal: implications for the treatment of acetaminophen poisoning.

STUDY OBJECTIVE: To determine if the presence of N-acetylcysteine reduces the ability of activated charcoal to adsorb acetaminophen both in the absence and presence of a coingestant. DESIGN: In vitro laboratory study. SETTING: University hospital research laboratory. MEASUREMENTS AND MAIN RESULTS: The adsorption of acetaminophen and salicylic acid by activated charcoal in the presence and absence of N-acetylcysteine was measured in vitro. Acetaminophen and salicylic acid analyses were conducted with high-performance liquid chromatography. Adsorption data were compared using the appropriate parametric statistical test. The addition of N-acetylcysteine significantly decreased the binding of acetaminophen by activated charcoal (p<0.005). When salicylic acid was added to simulate a coingestant, N-acetylcysteine significantly decreased salicylate adsorption by charcoal (p<0.001). CONCLUSIONS: The presence of N-acetylcysteine reduces the ability of activated charcoal to adsorb acetaminophen and coingestants. In vivo data will be required to determine the clinical relevance of these interactions.     

Optimal antidotal dose of activated charcoal

Activated charcoal is an effective antidote for reducing the gastrointestinal absorption of numerous ingested chemicals. However, the dose of activated charcoal for clinical use has often been recommended on the basis of in vitro data. Use of such data tends to overestimate the antidotal capacity of activated charcoal and may result in undertreatment with the adsorbent, whereas in vivo data are believed to be more reliable. The present study quantifies the capacity of activated charcoal to bind 3 drugs, pentobarbital sodium, chloroquine phosphate, and isoniazid in vivo. A fixed dose of each drug was administered to rats and mean control tissue concentrations of the drugs were determined at peak time. The identical dose of each drug was then administered to groups of rats which were immediately antidoted with activated charcoal in a dose of 1, 2,4 or 8 times the weight of the drug. Tissue concentrations of the drugs were then determined and the results were calculated and expressed as percent reduction of tissue drug concentrations, on the basis of the control tissue drug concentration values. Charcoal-drug ratios of 1:1, 2:1, 4:1 and 8:1 reduced absorption as follows: pentobarbital sodium, 7, 38, 62 and 89%; chloroquin phosphate, 20, 30, 70 and 96%; and isoniazid, 1.2, 7.2, 35 and 80%. Binding of drugs by activated charcoal at the 3 lower charcoal-drug ratios was highly variable between drugs. Only the highest charcoal-drug ratio provided uniform and nearly complete binding of the 3 drugs. The results suggest that the optimal activated charcoal-drug ratio for the treatment of pentobarbital, chloroquine, and isoniazid is at least 8:1.     

The preadministration of activated charcoal and aspirin absorption.

There is little information describing the effects of activated charcoal preadministration on drug absorption. This study was undertaken to determine the effect of activated charcoal preadministration at two different times on aspirin absorption. Fifteen volunteer subjects completed three study phases: 1) 975 mg aspirin alone, 2) 975 mg aspirin 30 min after 10 g activated charcoal, and 3) 975 mg aspirin 60 min after 10 g activated charcoal. Urine was collected for 48 h after the initiation of each study phase, and total aspirin recovery determined by HPLC. The aspirin recovery was 88.8% +/- 4.5% for the control phase, and 84.8% +/- 9.4% (Phase 1) and 85.8% +/- 12.6% (Phase 2) for the activated charcoal treatments (p > 0.05). These results suggest that activated charcoal administered 30 and 60 min prior to drug ingestion has little effect on drug absorption. Further studies of the effect of charcoal preadministration on the absorption of other drugs may provide useful information regarding factors important in determining activated charcoal efficacy.