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Postgraduate Medical Journal Jul 1980Paracetamol is an analgesic and antipyretic agent which was first marketed for use as a drug in the U.K. in 1956. It has since become popular with the medical profession... (Review)
Review
Paracetamol is an analgesic and antipyretic agent which was first marketed for use as a drug in the U.K. in 1956. It has since become popular with the medical profession and the general public as an alternative to aspirin.
Topics: Acetaminophen; Acetylcysteine; Adult; Animals; Chemical and Drug Induced Liver Injury; Child; Cysteamine; Dextropropoxyphene; Humans; Infant; Kidney Diseases; Methionine
PubMed: 7003571
DOI: 10.1136/pgmj.56.657.459 -
The Cochrane Database of Systematic... Feb 2018Paracetamol (acetaminophen) is the most widely used non-prescription analgesic in the world. Paracetamol is commonly taken in overdose either deliberately or... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Paracetamol (acetaminophen) is the most widely used non-prescription analgesic in the world. Paracetamol is commonly taken in overdose either deliberately or unintentionally. In high-income countries, paracetamol toxicity is a common cause of acute liver injury. There are various interventions to treat paracetamol poisoning, depending on the clinical status of the person. These interventions include inhibiting the absorption of paracetamol from the gastrointestinal tract (decontamination), removal of paracetamol from the vascular system, and antidotes to prevent the formation of, or to detoxify, metabolites.
OBJECTIVES
To assess the benefits and harms of interventions for paracetamol overdosage irrespective of the cause of the overdose.
SEARCH METHODS
We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (January 2017), CENTRAL (2016, Issue 11), MEDLINE (1946 to January 2017), Embase (1974 to January 2017), and Science Citation Index Expanded (1900 to January 2017). We also searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov database (US National Institute of Health) for any ongoing or completed trials (January 2017). We examined the reference lists of relevant papers identified by the search and other published reviews.
SELECTION CRITERIA
Randomised clinical trials assessing benefits and harms of interventions in people who have ingested a paracetamol overdose. The interventions could have been gastric lavage, ipecacuanha, or activated charcoal, or various extracorporeal treatments, or antidotes. The interventions could have been compared with placebo, no intervention, or to each other in differing regimens.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data from the included trials. We used fixed-effect and random-effects Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of the review outcomes. We used the Cochrane 'Risk of bias' tool to assess the risks of bias (i.e. systematic errors leading to overestimation of benefits and underestimation of harms). We used Trial Sequential Analysis to control risks of random errors (i.e. play of chance) and GRADE to assess the quality of the evidence and constructed 'Summary of findings' tables using GRADE software.
MAIN RESULTS
We identified 11 randomised clinical trials (of which one acetylcysteine trial was abandoned due to low numbers recruited), assessing several different interventions in 700 participants. The variety of interventions studied included decontamination, extracorporeal measures, and antidotes to detoxify paracetamol's toxic metabolite; which included methionine, cysteamine, dimercaprol, or acetylcysteine. There were no randomised clinical trials of agents that inhibit cytochrome P-450 to decrease the activation of the toxic metabolite N-acetyl-p-benzoquinone imine.Of the 11 trials, only two had two common outcomes, and hence, we could only meta-analyse two comparisons. Each of the remaining comparisons included outcome data from one trial only and hence their results are presented as described in the trials. All trial analyses lack power to access efficacy. Furthermore, all the trials were at high risk of bias. Accordingly, the quality of evidence was low or very low for all comparisons. Interventions that prevent absorption, such as gastric lavage, ipecacuanha, or activated charcoal were compared with placebo or no intervention and with each other in one four-armed randomised clinical trial involving 60 participants with an uncertain randomisation procedure and hence very low quality. The trial presented results on lowering plasma paracetamol levels. Activated charcoal seemed to reduce the absorption of paracetamol, but the clinical benefits were unclear. Activated charcoal seemed to have the best risk:benefit ratio among gastric lavage, ipecacuanha, or supportive treatment if given within four hours of ingestion. There seemed to be no difference between gastric lavage and ipecacuanha, but gastric lavage and ipecacuanha seemed more effective than no treatment (very low quality of evidence). Extracorporeal interventions included charcoal haemoperfusion compared with conventional treatment (supportive care including gastric lavage, intravenous fluids, and fresh frozen plasma) in one trial with 16 participants. The mean cumulative amount of paracetamol removed was 1.4 g. One participant from the haemoperfusion group who had ingested 135 g of paracetamol, died. There were no deaths in the conventional treatment group. Accordingly, we found no benefit of charcoal haemoperfusion (very low quality of evidence). Acetylcysteine appeared superior to placebo and had fewer adverse effects when compared with dimercaprol or cysteamine. Acetylcysteine superiority to methionine was unproven. One small trial (low quality evidence) found that acetylcysteine may reduce mortality in people with fulminant hepatic failure (Peto OR 0.29, 95% CI 0.09 to 0.94). The most recent randomised clinical trials studied different acetylcysteine regimens, with the primary outcome being adverse events. It was unclear which acetylcysteine treatment protocol offered the best efficacy, as most trials were underpowered to look at this outcome. One trial showed that a modified 12-hour acetylcysteine regimen with a two-hour acetylcysteine 100 mg/kg bodyweight loading dose was associated with significantly fewer adverse reactions compared with the traditional three-bag 20.25-hour regimen (low quality of evidence). All Trial Sequential Analyses showed lack of sufficient power. Children were not included in the majority of trials. Hence, the evidence pertains only to adults.
AUTHORS' CONCLUSIONS
These results highlight the paucity of randomised clinical trials comparing different interventions for paracetamol overdose and their routes of administration and the low or very low level quality of the evidence that is available. Evidence from a single trial found activated charcoal seemed the best choice to reduce absorption of paracetamol. Acetylcysteine should be given to people at risk of toxicity including people presenting with liver failure. Further randomised clinical trials with low risk of bias and adequate number of participants are required to determine which regimen results in the fewest adverse effects with the best efficacy. Current management of paracetamol poisoning worldwide involves the administration of intravenous or oral acetylcysteine which is based mainly on observational studies. Results from these observational studies indicate that treatment with acetylcysteine seems to result in a decrease in morbidity and mortality, However, further evidence from randomised clinical trials comparing different treatments are needed.
Topics: Acetaminophen; Acetylcysteine; Analgesics, Non-Narcotic; Antidotes; Charcoal; Cysteamine; Dimercaprol; Drug Overdose; Gastric Lavage; Humans; Intestinal Absorption; Liver Failure, Acute; Liver Transplantation; Methionine; Randomized Controlled Trials as Topic
PubMed: 29473717
DOI: 10.1002/14651858.CD003328.pub3 -
American Journal of Physiology. Cell... Jan 2018Cigarette-smoke (CS) exposure and aging are the leading causes of chronic obstructive pulmonary disease (COPD)-emphysema development, although the molecular mechanism...
Cigarette-smoke (CS) exposure and aging are the leading causes of chronic obstructive pulmonary disease (COPD)-emphysema development, although the molecular mechanism that mediates disease pathogenesis remains poorly understood. Our objective was to investigate the impact of CS exposure and aging on autophagy and the pathophysiological changes associated with lung aging (senescence) and emphysema progression. Beas2b cells, C57BL/6 mice, and human (GOLD 0-IV) lung tissues were used to determine the central mechanism involved in CS/age-related COPD-emphysema pathogenesis. Beas2b cells and murine lungs exposed to cigarette smoke extract (CSE)/CS showed a significant ( P < 0.05) accumulation of poly-ubiquitinated proteins and impaired autophagy marker, p62, in aggresome bodies. Moreover, treatment with the autophagy-inducing antioxidant drug cysteamine significantly ( P < 0.001) decreased CSE/CS-induced aggresome bodies. We also found a significant ( P < 0.001) increase in levels of aggresome bodies in the lungs of smokers and COPD subjects in comparison to nonsmoker controls. Furthermore, the presence and levels of aggresome bodies statistically correlated with severity of emphysema and alveolar senescence. In addition to CS exposure, lungs from old mice also showed accumulation of aggresome bodies, suggesting this as a common mechanism to initiate cellular senescence and emphysema. Additionally, Beas2b cells and murine lungs exposed to CSE/CS showed cellular apoptosis and senescence, which were both controlled by cysteamine treatment. In parallel, we evaluated the impact of CS on pulmonary exacerbation, using mice exposed to CS and/or infected with Pseudomonas aeruginosa ( Pa), and confirmed cysteamine's potential as an autophagy-inducing antibacterial drug, based on its ability to control CS-induced pulmonary exacerbation ( Pa-bacterial counts) and resulting inflammation. CS induced autophagy impairment accelerates lung aging and COPD-emphysema exacerbations and pathogenesis.
Topics: Animals; Autophagy; Case-Control Studies; Cell Line; Cellular Senescence; Cigarette Smoking; Cysteamine; Cytokines; Disease Models, Animal; Disease Progression; Epithelial Cells; Humans; Inclusion Bodies; Inflammation Mediators; Lung; Mice, Inbred C57BL; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Sequestosome-1 Protein; Severity of Illness Index; Smoke; Ubiquitination
PubMed: 27413169
DOI: 10.1152/ajpcell.00110.2016 -
Cells Dec 2021Cystinosis is a rare inheritable lysosomal storage disorder characterized by cystine accumulation throughout the body, chronic kidney disease necessitating renal... (Review)
Review
Cystinosis is a rare inheritable lysosomal storage disorder characterized by cystine accumulation throughout the body, chronic kidney disease necessitating renal replacement therapy mostly during adolescence, and multiple extra-renal complications. The majority of male cystinosis patients are infertile due to azoospermia, in contrast to female patients who are fertile. Over recent decades, the fertility status of male patients has evolved from a primary hypogonadism in the era before the systematic treatment with cysteamine to azoospermia in the majority of cysteamine-treated infantile cystinosis patients. In this review, we provide a state-of-the-art overview on the available clinical, histopathological, animal, and in vitro data. We summarize current insights on both cystinosis males and females, and their clinical implications including the potential effect of cysteamine on fertility. In addition, we identify the remaining challenges and areas for future research.
Topics: Animals; Biomarkers; Cysteamine; Cystinosis; Disease Models, Animal; Fertility; Humans; Models, Biological
PubMed: 34944047
DOI: 10.3390/cells10123539 -
Cells Feb 2022Cystinosis is a lethal autosomal recessive disease that has been known clinically for over 100 years. There are now specific treatments including dialysis, renal... (Review)
Review
Cystinosis is a lethal autosomal recessive disease that has been known clinically for over 100 years. There are now specific treatments including dialysis, renal transplantation and the orphan drug, cysteamine, which greatly improve the duration and quality of patient life, however, the cellular mechanisms responsible for the phenotype are unknown. One cause, programmed cell death, is clearly involved. Study of extant literature via Pubmed on "programmed cell death" and "apoptosis" forms the basis of this review. Most of such studies involved apoptosis. Numerous model systems and affected tissues in cystinosis have shown an increased rate of apoptosis that can be partially reversed with cysteamine. Proposed mechanisms have included changes in protein signaling pathways, autophagy, gene expression programs, and oxidative stress.
Topics: Apoptosis; Autophagy; Cysteamine; Cystinosis; Humans; Kidney Transplantation
PubMed: 35203319
DOI: 10.3390/cells11040670 -
Bioscience Reports Oct 2018Cystamine is commonly used as a transglutaminase inhibitor. This disulphide undergoes reduction to the aminothiol compound, cysteamine. Thus, the mechanism by which... (Review)
Review
Cystamine is commonly used as a transglutaminase inhibitor. This disulphide undergoes reduction to the aminothiol compound, cysteamine. Thus, the mechanism by which cystamine inhibits transglutaminase activity could be due to either cystamine or cysteamine, which depends on the local redox environment. Cystamine inactivates transglutaminases by promoting the oxidation of two vicinal cysteine residues on the enzyme to an allosteric disulphide, whereas cysteamine acts as a competitive inhibitor for transamidation reactions catalyzed by this enzyme. The latter mechanism is likely to result in the formation of a unique biomarker, -(γ-glutamyl)cysteamine that could serve to indicate how cyst(e)amine acts to inhibit transglutaminases inside cells and the body.
Topics: Biomarkers; Cystamine; Cysteamine; Cysteine; Enzyme Inhibitors; Humans; Oxidation-Reduction; Transglutaminases
PubMed: 30054429
DOI: 10.1042/BSR20180691 -
Journal of Inherited Metabolic Disease Jul 2017Cysteamine is a small aminothiol endogenously derived from coenzyme A degradation. For some decades, synthetic cysteamine has been employed for the treatment of... (Review)
Review
Cysteamine is a small aminothiol endogenously derived from coenzyme A degradation. For some decades, synthetic cysteamine has been employed for the treatment of cystinosis, and new uses of the drug continue to emerge. In this review, we discuss the role of cysteamine in cellular and extracellular homeostasis and focus on the potential use of aminothiols to reconstitute the function of proteins harboring arginine (Arg) to cysteine (Cys) mutations, via repair of the Cys residue into a moiety that introduces an amino group, as seen in basic amino acid residues Lys and Arg. Cysteamine has been utilized in vitro and ex vivo in four different genetic disorders, and thus provides "proof of principle" that aminothiols can modify Cys residues. Other aminothiols such as mercaptoethylguanidine (MEG) with closer structural resemblance to the guanidinium moiety of Arg are under examination for their predicted enhanced capacity to reconstitute loss of function. Although the use of aminothiols holds clinical potential, more studies are required to refine specificity and treatment design. The efficacy of aminothiols to target proteins may vary substantially depending on their specific extracellular and intracellular locations. Redox potential, pH, and specific aminothiol abundance in each physiological compartment are expected to influence the reactivity and turnover of cysteamine and analogous drugs. Upcoming research will require the use of suitable cell and animal models featuring Arg to Cys mutations. Since, in general, Arg to Cys changes comprise about 8% of missense mutations, repair of this specific mutation may provide promising avenues for many genetic diseases.
Topics: Animals; Apolipoprotein E3; Arginine; Argininosuccinate Lyase; Cystathionine beta-Synthase; Cysteamine; Cysteine; Cystinosis; Homeostasis; Humans; Hydrogen-Ion Concentration; Molecular Conformation; Mutation; Mutation, Missense; Oxidation-Reduction; Sulfhydryl Compounds; Thromboplastin
PubMed: 28643139
DOI: 10.1007/s10545-017-0060-4 -
European Journal of Pharmaceutical... Jan 2022Skin hyperpigmentation is caused by an excessive production of melanin. Cysteamine, an aminothiol compound physiologically synthetized in human body cells, is known as...
Skin hyperpigmentation is caused by an excessive production of melanin. Cysteamine, an aminothiol compound physiologically synthetized in human body cells, is known as depigmenting agent. The aim of this study was to evaluate the depigmenting activity and skin penetration of liposome formulations encapsulating cysteamine hydrochloride. First, cysteamine hydrochloride-loaded liposomes were prepared and characterized for their size, polydispersity index, zeta potential and the encapsulation efficiency of the active molecule. The stability of cysteamine hydrochloride in the prepared liposome formulations in suspension and freeze-dried forms was then assessed. The in vitro cytotoxicity of cysteamine and cysteamine-loaded liposome suspensions (either original or freeze-dried) was evaluated in B16 murine melanoma cells. The measurement of melanin and tyrosinase activities was assessed after cells treatment with free and encapsulated cysteamine. The antioxidant activity of the free and encapsulated cysteamine was evaluated by the measurement of ROS formation in treated cells. The ex vivo human skin penetration study was also performed using Franz diffusion cell. The stability of cysteamine hydrochloride was improved after encapsulation in liposomal suspension. In addition, for the liposome re-suspended after freeze-drying, a significant increase of vesicle stability was observed. The free and the encapsulated cysteamine in suspension (either original or freeze-dried) did not show any cytotoxic effect, inhibited the melanin synthesis as well as the tyrosinase activity. An antioxidant activity was observed for the free and the encapsulated cysteamine hydrochloride. The encapsulation enhanced the skin penetration of cysteamine hydrochloride. The penetration of this molecule was better for the re-suspended freeze-dried form than the original liposomal suspension where the drug was found retained in the epidermis layer of the skin.
Topics: Animals; Cysteamine; Freeze Drying; Humans; Liposomes; Mice; Skin; Skin Absorption
PubMed: 34822973
DOI: 10.1016/j.ejps.2021.106082 -
The Journal of Organic Chemistry Aug 2022We report the synthesis, chemical properties, and disulfide bond-reducing performance of a dithiol called NACMEAA, conceived as a hybrid of two biologically relevant...
We report the synthesis, chemical properties, and disulfide bond-reducing performance of a dithiol called NACMEAA, conceived as a hybrid of two biologically relevant thiols: cysteine and cysteamine. NACMEAA is conveniently prepared from inexpensive l-cystine in an efficient manner. As a nonvolatile, highly soluble, and neutral compound at physiological pH with the first thiol p value of 8.0, NACMEAA is reactive and user-friendly. We also demonstrate that NACMEAA reduces disulfide bonds in GSSG and lysozyme.
Topics: Cysteamine; Cysteine; Disulfides; Oxidation-Reduction; Reducing Agents; Sulfhydryl Compounds; Toluene
PubMed: 35862282
DOI: 10.1021/acs.joc.2c01050 -
International Journal of Molecular... Apr 2020Patients with chronic kidney disease (CKD) display significant mineral and bone disorders (CKD-MBD) that induce significant cardiovascular, growth and bone... (Review)
Review
Patients with chronic kidney disease (CKD) display significant mineral and bone disorders (CKD-MBD) that induce significant cardiovascular, growth and bone comorbidities. Nephropathic cystinosis is an inherited metabolic disorder caused by the lysosomal accumulation of cystine due to mutations in the gene encoding cystinosin, and leads to end-stage renal disease within the second decade. The cornerstone of management relies on cysteamine therapy to decrease lysosomal cystine accumulation in target organs. However, despite cysteamine therapy, patients display severe bone symptoms, and the concept of "cystinosis metabolic bone disease" is currently emerging. Even though its exact pathophysiology remains unclear, at least five distinct but complementary entities can explain bone impairment in addition to CKD-MBD: long-term consequences of renal Fanconi syndrome, malnutrition and copper deficiency, hormonal disturbances, myopathy, and intrinsic/iatrogenic bone defects. Direct effects of both mutation and cysteamine on osteoblasts and osteoclasts are described. Thus, the main objective of this manuscript is not only to provide a clinical update on bone disease in cystinosis, but also to summarize the current experimental evidence demonstrating a functional impairment of bone cells in this disease and to discuss new working hypotheses that deserve future research in the field.
Topics: Amino Acid Transport Systems, Neutral; Animals; Bone Diseases; Bone Remodeling; Chronic Kidney Disease-Mineral and Bone Disorder; Cysteamine; Cystinosis; Humans; Mutation
PubMed: 32354056
DOI: 10.3390/ijms21093109