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The Cochrane Database of Systematic... Mar 2018Prolonged treatment with benzodiazepines is common practice despite clinical recommendations of short-term use. Benzodiazepines are used by approximately 4% of the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Prolonged treatment with benzodiazepines is common practice despite clinical recommendations of short-term use. Benzodiazepines are used by approximately 4% of the general population, with increased prevalence in psychiatric populations and the elderly. After long-term use it is often difficult to discontinue benzodiazepines due to psychological and physiological dependence. This review investigated if pharmacological interventions can facilitate benzodiazepine tapering.
OBJECTIVES
To assess the benefits and harms of pharmacological interventions to facilitate discontinuation of chronic benzodiazepine use.
SEARCH METHODS
We searched the following electronic databases up to October 2017: Cochrane Drugs and Alcohol Group's Specialised Register of Trials, CENTRAL, PubMed, Embase, CINAHL, and ISI Web of Science. We also searched ClinicalTrials.gov, the WHO ICTRP, and ISRCTN registry, and checked the reference lists of included studies for further references to relevant randomised controlled trials.
SELECTION CRITERIA
We included randomised controlled trials comparing pharmacological treatment versus placebo or no intervention or versus another pharmacological intervention in adults who had been treated with benzodiazepines for at least two months and/or fulfilled criteria for benzodiazepine dependence (any criteria).
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane.
MAIN RESULTS
We included 38 trials (involving 2543 participants), but we could only extract data from 35 trials with 2295 participants. Many different interventions were studied, and no single intervention was assessed in more than four trials. We extracted data on 18 different comparisons. The risk of bias was high in all trials but one. Trial Sequential Analysis showed imprecision for all comparisons.For benzodiazepine discontinuation, we found a potential benefit of valproate at end of intervention (1 study, 27 participants; risk ratio (RR) 2.55, 95% confidence interval (CI) 1.08 to 6.03; very low-quality evidence) and of tricyclic antidepressants at longest follow-up (1 study, 47 participants; RR 2.20, 95% CI 1.27 to 3.82; low-quality evidence).We found potentially positive effects on benzodiazepine withdrawal symptoms of pregabalin (1 study, 106 participants; mean difference (MD) -3.10 points, 95% CI -3.51 to -2.69; very low-quality evidence), captodiame (1 study, 81 participants; MD -1.00 points, 95% CI -1.13 to -0.87; very low-quality evidence), paroxetine (2 studies, 99 participants; MD -3.57 points, 95% CI -5.34 to -1.80; very low-quality evidence), tricyclic antidepressants (1 study, 38 participants; MD -19.78 points, 95% CI -20.25 to -19.31; very low-quality evidence), and flumazenil (3 studies, 58 participants; standardised mean difference -0.95, 95% CI -1.71 to -0.19; very low-quality evidence) at end of intervention. However, the positive effect of paroxetine on benzodiazepine withdrawal symptoms did not persist until longest follow-up (1 study, 54 participants; MD -0.13 points, 95% CI -4.03 to 3.77; very low-quality evidence).The following pharmacological interventions reduced symptoms of anxiety at end of intervention: carbamazepine (1 study, 36 participants; MD -6.00 points, 95% CI -9.58 to -2.42; very low-quality evidence), pregabalin (1 study, 106 participants; MD -4.80 points, 95% CI -5.28 to -4.32; very low-quality evidence), captodiame (1 study, 81 participants; MD -5.70 points, 95% CI -6.05 to -5.35; very low-quality evidence), paroxetine (2 studies, 99 participants; MD -6.75 points, 95% CI -9.64 to -3.86; very low-quality evidence), and flumazenil (1 study, 18 participants; MD -1.30 points, 95% CI -2.28 to -0.32; very low-quality evidence).Two pharmacological treatments seemed to reduce the proportion of participants that relapsed to benzodiazepine use: valproate (1 study, 27 participants; RR 0.31, 95% CI 0.11 to 0.90; very low-quality evidence) and cyamemazine (1 study, 124 participants; RR 0.33, 95% CI 0.14 to 0.78; very low-quality evidence). Alpidem decreased the proportion of participants with benzodiazepine discontinuation (1 study, 25 participants; RR 0.41, 95% CI 0.17 to 0.99; number needed to treat for an additional harmful outcome (NNTH) 2.3 participants; low-quality evidence) and increased the occurrence of withdrawal syndrome (1 study, 145 participants; RR 4.86, 95% CI 1.12 to 21.14; NNTH 5.9 participants; low-quality evidence). Likewise, magnesium aspartate decreased the proportion of participants discontinuing benzodiazepines (1 study, 144 participants; RR 0.80, 95% CI 0.66 to 0.96; NNTH 5.8; very low-quality evidence).Generally, adverse events were insufficiently reported. Specifically, one of the flumazenil trials was discontinued due to severe panic reactions.
AUTHORS' CONCLUSIONS
Given the low or very low quality of the evidence for the reported outcomes, and the small number of trials identified with a limited number of participants for each comparison, it is not possible to draw firm conclusions regarding pharmacological interventions to facilitate benzodiazepine discontinuation in chronic benzodiazepine users. Due to poor reporting, adverse events could not be reliably assessed across trials. More randomised controlled trials are required with less risk of systematic errors ('bias') and of random errors ('play of chance') and better and full reporting of patient-centred and long-term clinical outcomes. Such trials ought to be conducted independently of industry involvement.
Topics: Adult; Antidepressive Agents; Aspartic Acid; Benzodiazepines; Buspirone; Carbamazepine; Ethylamines; Flumazenil; Homeopathy; Humans; Imidazoles; Lithium Compounds; Melatonin; Paroxetine; Pregabalin; Progesterone; Pyridines; Randomized Controlled Trials as Topic; Substance Withdrawal Syndrome; Sulfides; Withholding Treatment
PubMed: 29543325
DOI: 10.1002/14651858.CD011481.pub2 -
Nature Jul 2018Fast inhibitory neurotransmission in the brain is principally mediated by the neurotransmitter GABA (γ-aminobutyric acid) and its synaptic target, the type A GABA...
Fast inhibitory neurotransmission in the brain is principally mediated by the neurotransmitter GABA (γ-aminobutyric acid) and its synaptic target, the type A GABA receptor (GABA receptor). Dysfunction of this receptor results in neurological disorders and mental illnesses including epilepsy, anxiety and insomnia. The GABA receptor is also a prolific target for therapeutic, illicit and recreational drugs, including benzodiazepines, barbiturates, anaesthetics and ethanol. Here we present high-resolution cryo-electron microscopy structures of the human α1β2γ2 GABA receptor, the predominant isoform in the adult brain, in complex with GABA and the benzodiazepine site antagonist flumazenil, the first-line clinical treatment for benzodiazepine overdose. The receptor architecture reveals unique heteromeric interactions for this important class of inhibitory neurotransmitter receptor. This work provides a template for understanding receptor modulation by GABA and benzodiazepines, and will assist rational approaches to therapeutic targeting of this receptor for neurological disorders and mental illness.
Topics: Benzodiazepines; Bicuculline; Binding, Competitive; Brain Chemistry; Cell Membrane; Cryoelectron Microscopy; Flumazenil; GABA Modulators; Glycosylation; HEK293 Cells; Humans; Immunoglobulin Fab Fragments; Ligands; Models, Molecular; Receptors, GABA-A; gamma-Aminobutyric Acid
PubMed: 29950725
DOI: 10.1038/s41586-018-0255-3 -
Basic & Clinical Pharmacology &... Jan 2016Flumazenil is used for the reversal of benzodiazepine overdose. Serious adverse events (SAEs) including seizures and cardiac arrhythmias have been reported in patients... (Meta-Analysis)
Meta-Analysis Review
Adverse Events Associated with Flumazenil Treatment for the Management of Suspected Benzodiazepine Intoxication--A Systematic Review with Meta-Analyses of Randomised Trials.
Flumazenil is used for the reversal of benzodiazepine overdose. Serious adverse events (SAEs) including seizures and cardiac arrhythmias have been reported in patients treated with flumazenil, and the clinical advantage of flumazenil treatment has been questioned. The objective was to assess the risk of (S)AEs associated with the use of flumazenil in patients with impaired consciousness due to known or suspected benzodiazepine overdose. Studies included in the meta-analyses were identified by literature search in Medline, Cochrane Library and Embase using combinations of the words flumazenil, benzodiazepines, anti-anxiety agents, poisoning, toxicity and overdose. Randomised clinical trials (RCTs) in verified or suspected benzodiazepine overdose patients comparing treatment with flumazenil versus placebo were included. Pre-defined outcome measures were AEs, SAEs and mortality. Thirteen trials with a total of 994 randomised (990 evaluable) patients were included. AEs were significantly more common in the flumazenil group (138/498) compared with the placebo group (47/492) (risk ratio: 2.85; 95% confidence interval: 2.11-3.84; p < 0.00001). SAEs were also significantly more common in the flumazenil group compared with the placebo group (12/498 versus 2/492; risk ratio: 3.81; 95% CI: 1.28-11.39; p = 0.02). The most common AEs in the flumazenil group were agitation and gastrointestinal symptoms, whereas the most common SAEs were supraventricular arrhythmia and convulsions. No patients died during the blinded phase of the RCTs. The use of flumazenil in a population admitted at the emergency department with known or suspected benzodiazepine intoxication is associated with a significantly increased risk of (S)AEs compared with placebo. Flumazenil should not be used routinely, and the harms and benefits should be considered carefully in every patient.
Topics: Antidotes; Benzodiazepines; Drug Overdose; Flumazenil; Humans; Randomized Controlled Trials as Topic; Receptors, GABA-A
PubMed: 26096314
DOI: 10.1111/bcpt.12434 -
British Journal of Clinical Pharmacology Mar 2016Flumazenil and naloxone are considered to be pharmacologically ideal antidotes. By competitive binding at the molecular target receptors, they are highly specific... (Review)
Review
Flumazenil and naloxone are considered to be pharmacologically ideal antidotes. By competitive binding at the molecular target receptors, they are highly specific antagonists of two important drug classes, the benzodiazepines and opioids, respectively. Both antidotes enjoy rapid onset and short duration after parenteral administration, are easily titrated and are essentially devoid of agonist effects. Yet only naloxone is widely used as a component of the 'coma cocktail', a sequence of empirical treatments to correct altered mental status, while experts discourage the use of flumazenil for such patients. This review contrasts the history, indications, published evidence and novel applications for each antidote in order to explain this disparity in the clinical use of these 'ideal' antidotes.
Topics: Analgesics, Opioid; Antidotes; Benzodiazepines; Coma; Drug Overdose; Flumazenil; Humans; Naloxone
PubMed: 26469689
DOI: 10.1111/bcp.12731 -
The Journal of Experimental Medicine Dec 2022Lethal intestinal tissue toxicity is a common side effect and a dose-limiting factor in chemoradiotherapy. Chemoradiotherapy can trigger DNA damage and induce...
Lethal intestinal tissue toxicity is a common side effect and a dose-limiting factor in chemoradiotherapy. Chemoradiotherapy can trigger DNA damage and induce P53-dependent apoptosis in LGR5+ intestinal stem cells (ISCs). Gamma-aminobutyric acid (GABA) and its A receptors (GABAAR) are present in the gastrointestinal tract. However, the functioning of the GABAergic system in ISCs is poorly defined. We found that GABAAR α1 (GABRA1) levels increased in the murine intestine after chemoradiotherapy. GABRA1 depletion in LGR5+ ISCs protected the intestine from chemoradiotherapy-induced P53-dependent apoptosis and prolonged animal survival. The administration of bicuculline, a GABAAR antagonist, prevented chemoradiotherapy-induced ISC loss and intestinal damage without reducing the chemoradiosensitivity of tumors. Mechanistically, it was associated with the reduction of reactive oxygen species-induced DNA damage via the L-type voltage-dependent Ca2+ channels. Notably, flumazenil, a GABAAR antagonist approved by the U.S. Food and Drug Administration, rescued human colonic organoids from chemoradiotherapy-induced toxicity. Therefore, flumazenil may be a promising drug for reducing the gastrointestinal side effects of chemoradiotherapy.
Topics: Animals; Bicuculline; Calcium; Chemoradiotherapy; Flumazenil; Humans; Intestines; Mice; Reactive Oxygen Species; Receptors, GABA-A; Stem Cells; Tumor Suppressor Protein p53; United States; gamma-Aminobutyric Acid
PubMed: 36125780
DOI: 10.1084/jem.20220541 -
Journal of Medical Toxicology :... Jun 2014
Topics: Alcohol Deterrents; Alcohol Withdrawal Delirium; Alcohol Withdrawal Seizures; Antidotes; Delirium; Drug Monitoring; Ethanol; Flumazenil; GABA Modulators; Humans; Hypnotics and Sedatives; Neurotoxicity Syndromes; Substance Withdrawal Syndrome
PubMed: 24595919
DOI: 10.1007/s13181-014-0392-5 -
The Cochrane Database of Systematic... Jul 2017Hepatic encephalopathy is a common complication of cirrhosis which results in poor brain functioning. The spectrum of changes associated with hepatic encephalopathy... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Hepatic encephalopathy is a common complication of cirrhosis which results in poor brain functioning. The spectrum of changes associated with hepatic encephalopathy ranges from the clinically 'indiscernible' or minimal hepatic encephalopathy to the clinically 'obvious' or overt hepatic encephalopathy. Flumazenil is a synthetic benzodiazepine antagonist with high affinity for the central benzodiazepine recognition site. Flumazenil may benefit people with hepatic encephalopathy through an indirect negative allosteric modulatory effect on gamma-aminobutyric acid receptor function. The previous version of this review, which included 13 randomised clinical trials, found no effect of flumazenil on all-cause mortality, based on an analysis of 10 randomised clinical trials, but found a beneficial effect on hepatic encephalopathy, based on an analysis of eight randomised clinical trials.
OBJECTIVES
To evaluate the beneficial and harmful effects of flumazenil versus placebo or no intervention for people with cirrhosis and hepatic encephalopathy.
SEARCH METHODS
We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, and LILACS; meeting and conference proceedings; and bibliographies in May 2017.
SELECTION CRITERIA
We included randomised clinical trials regardless of publication status, blinding, or language in the analyses of benefits and harms, and observational studies in the assessment of harms.
DATA COLLECTION AND ANALYSIS
Two review authors extracted data independently. We undertook meta-analyses and presented results using risk ratios (RR) with 95% confidence intervals (CI) and I values as a marker of heterogeneity. We assessed bias control using the Cochrane Hepato-Biliary Group domains; determined the quality of the evidence using GRADE; evaluated the risk of small-study effects in regression analyses; and conducted trial sequential, subgroup, and sensitivity analyses.
MAIN RESULTS
We identified 14 eligible randomised clinical trials with 867 participants, the majority of whom had an acute episode of overt hepatic encephalopathy. In addition, we identified one ongoing randomised clinical trial. We were unable to gather outcome data from 2 randomised clinical trials with 25 participants. Thus, our analyses include 842 participants from 12 randomised clinical trials comparing flumazenil versus placebo. We classified one randomised clinical trial at low risk of bias in the overall assessment and the remaining randomised clinical trials at high risk of bias. The duration of follow-up ranged from a few minutes to two weeks, but it was less than one day in the majority of the trials.In total, 32/433 (7.4%) participants allocated to flumazenil versus 38/409 (9.3%) participants allocated to placebo died (RR 0.75, 95% CI 0.48 to 1.16; 11 randomised clinical trials; low quality evidence). The Trial Sequential Analysis and the one randomised clinical trial assessed as low risk of bias (RR 0.76, 95% CI 0.37 to 1.53) found no beneficial or harmful effects of flumazenil on all-cause mortality. The methods used to evaluate hepatic encephalopathy included several different clinical scales, electrophysiological variables, and psychometric tests. Flumazenil was associated with a beneficial effect on hepatic encephalopathy when including all randomised clinical trials (RR 0.75, 95% CI 0.71 to 0.80; 824 participants; 9 randomised clinical trials; low quality evidence), or just the trial at low risk of bias (RR 0.78, 95% CI 0.72 to 0.84; 527 participants). The Trial Sequential Analysis supported a beneficial effect of flumazenil on hepatic encephalopathy. The randomised clinical trials included little information about causes of death and little information on non-fatal serious adverse events.
AUTHORS' CONCLUSIONS
We found low quality evidence suggesting a short-term beneficial effect of flumazenil on hepatic encephalopathy in people with cirrhosis, but no evidence of an effect on all-cause mortality. Additional evidence from large, high quality randomised clinical trials is needed to evaluate the potential benefits and harms of flumazenil in people with cirrhosis and hepatic encephalopathy.
Topics: Acute Disease; Antidotes; Cause of Death; Chronic Disease; Flumazenil; GABA Modulators; GABA-A Receptor Antagonists; Hepatic Encephalopathy; Humans; Liver Cirrhosis; Randomized Controlled Trials as Topic
PubMed: 28745801
DOI: 10.1002/14651858.CD002798.pub3 -
Neurology May 2017We report a case series of 10 patients with γ-aminobutyric acid (GABA)-transaminase deficiency including a novel therapeutic trial and an expanded phenotype. (Review)
Review
OBJECTIVE
We report a case series of 10 patients with γ-aminobutyric acid (GABA)-transaminase deficiency including a novel therapeutic trial and an expanded phenotype.
METHODS
Case ascertainment, literature review, comprehensive evaluations, and long-term treatment with flumazenil.
RESULTS
All patients presented with neonatal or early infantile-onset encephalopathy; other features were hypotonia, hypersomnolence, epilepsy, choreoathetosis, and accelerated linear growth. EEGs showed burst-suppression, modified hypsarrhythmia, multifocal spikes, and generalized spike-wave. Five of the 10 patients are currently alive with age at last follow-up between 18 months and 9.5 years. Treatment with continuous flumazenil was implemented in 2 patients. One patient, with a milder phenotype, began treatment at age 21 months and has continued for 20 months with improved alertness and less excessive adventitious movements. The second patient had a more severe phenotype and was 7 years of age at initiation of flumazenil, which was not continued.
CONCLUSIONS
GABA-transaminase deficiency presents with neonatal or infantile-onset encephalopathy including hypersomnolence and choreoathetosis. A widened phenotypic spectrum is reported as opposed to lethality by 2 years of age. The GABA-A benzodiazepine receptor antagonist flumazenil may represent a therapeutic strategy.
Topics: 4-Aminobutyrate Transaminase; Amino Acid Metabolism, Inborn Errors; Brain; Child; Child, Preschool; Diagnosis, Differential; Female; Flumazenil; Follow-Up Studies; GABA Modulators; Humans; Infant; Male; Phenotype
PubMed: 28411234
DOI: 10.1212/WNL.0000000000003936 -
Journal of Anesthesia Dec 2022
Topics: Flumazenil; Wakefulness; Benzodiazepines; Craniotomy
PubMed: 36094582
DOI: 10.1007/s00540-022-03103-1 -
Molecules (Basel, Switzerland) Dec 2022In the last decade, microfluidic techniques have been explored in radiochemistry, and some of them have been implemented in preclinical production. However, these are...
In the last decade, microfluidic techniques have been explored in radiochemistry, and some of them have been implemented in preclinical production. However, these are not suitable and reliable for preparing different types of radiotracers or dose-on-demand production. A fully automated iMiDEV™ microfluidic radiosynthesizer has been introduced and this study is aimed at using of the iMiDEV™ radiosynthesizer with a microfluidic cassette to produce [C]flumazenil and [C]-deprenyl. These two are known PET radioligands for benzodiazepine receptors and monoamine oxidase-B (MAO-B), respectively. Methods were successfully developed to produce [C]flumazenil and [C]-deprenyl using [C]methyl iodide and [C]methyl triflate, respectively. The final products 1644 ± 504 MBq ( = 7) and 533 ± 20 MBq ( = 3) of [C]flumazenil and [C]-deprenyl were produced with radiochemical purities were over 98% and the molar activity for [C]flumazenil and [C]-deprenyl was 1912 ± 552 GBq/µmol, and 1463 ± 439 GBq/µmol, respectively, at the end of synthesis. All the QC tests complied with the European Pharmacopeia. Different parameters, such as solvents, bases, methylating agents, precursor concentration, and different batches of cassettes, were explored to increase the radiochemical yield. Synthesis methods were developed using 3-5 times less precursor than conventional methods. The fully automated iMiDEV™ microfluidic radiosynthesizer was successfully applied to prepare [C]flumazenil and [C]-deprenyl.
Topics: Selegiline; Positron-Emission Tomography; Carbon; Flumazenil; Microfluidics; Carbon Radioisotopes; Radiopharmaceuticals
PubMed: 36557975
DOI: 10.3390/molecules27248843