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Drug Metabolism and Disposition: the... Feb 2023Phenobarbital (PB) is a commonly prescribed anti-epileptic drug that can also benefit newborns from hyperbilirubinemia. Being the first drug demonstrating hepatic... (Review)
Review
Phenobarbital (PB) is a commonly prescribed anti-epileptic drug that can also benefit newborns from hyperbilirubinemia. Being the first drug demonstrating hepatic induction of cytochrome P450 (CYP), PB has since been broadly used as a model compound to study xenobiotic-induced drug metabolism and clearance. Mechanistically, PB-mediated CYP induction is linked to a number of nuclear receptors, such as the constitutive androstane receptor (CAR), pregnane X receptor (PXR), and estrogen receptor , with CAR being the predominant regulator. Unlike prototypical agonistic ligands, PB-mediated activation of CAR does not involve direct binding with the receptor. Instead, dephosphorylation of threonine 38 in the DNA-binding domain of CAR was delineated as a key signaling event underlying PB-mediated indirect activation of CAR. Further studies revealed that such phosphorylation sites appear to be highly conserved among most human nuclear receptors. Interestingly, while PB is a pan-CAR activator in both animals and humans, PB activates human but not mouse PXR. The species-specific role of PB in gene regulation is a key determinant of its implication in xenobiotic metabolism, drug-drug interactions, energy homeostasis, and cell proliferation. In this review, we summarize the recent progress in our understanding of PB-provoked transactivation of nuclear receptors with a focus on CAR and PXR. SIGNIFICANCE STATEMENT: Extensive studies using PB as a research tool have significantly advanced our understanding of the molecular basis underlying nuclear receptor-mediated drug metabolism, drug-drug interactions, energy homeostasis, and cell proliferation. In particular, CAR has been established as a cell signaling-regulated nuclear receptor in addition to ligand-dependent functionality. This mini-review highlights the mechanisms by which PB transactivates CAR and PXR.
Topics: Infant, Newborn; Animals; Humans; Receptors, Steroid; Xenobiotics; Receptors, Cytoplasmic and Nuclear; Liver; Phenobarbital; Cytochrome P-450 Enzyme System
PubMed: 36351837
DOI: 10.1124/dmd.122.000859 -
Epilepsy Research Sep 2023Intravenous phenobarbital is frequently offered to patients with generalized convulsive status epilepticus (GCSE) in China, but its long-term benefits are unclear. We... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Intravenous phenobarbital is frequently offered to patients with generalized convulsive status epilepticus (GCSE) in China, but its long-term benefits are unclear. We aimed to evaluate the long-term effects of intravenous phenobarbital on adult patients with GCSE.
METHODS
This randomized clinical trial with a 12-month follow-up was performed in Xuanwu Hospital, Capital Medical University (Beijing, China) between February 2011 and December 2021. After the failure of intravenous diazepam treatment, adult patients with GCSE were randomized to receive either intravenous phenobarbital or valproate. Neurological outcome within 12-month was dichotomized as good (modified Rankin scale, mRS 0-2) or poor (mRS 3-6). Cognitive function was measured by mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA). Hamilton anxiety scale (HAMA) and Hamilton depression scale (HAMD) were tested for mood disorders.
RESULTS
We consecutively recruited 166 patients with GCSE. After excluding individuals with termination after intravenous diazepam (n = 61), and with other exclusion criteria (n = 7), 98 patients were included and 88.0% (66/75) of survivors achieved seizure freedom at 12-month. Forty-five patients (45.92%) had good outcomes at 3-month and 57 patients (58.16%) had good outcomes at 12-month. And 46.67% (35/75) of survivors showed mRS improvement at 12-month (phenobarbital group, n = 17 vs. valproate group, n = 18, P = 0.321). Despite there was no significant difference with respect to good outcomes at 3-month (54.0% vs. 37.5%, P = 0.101), the rate of good outcomes in phenobarbital group was higher than valproate group at 12-month (68.0% vs. 47.92%, P = 0.044). A total of 43 patients successfully participated cognitive and emotional tests. Mild cognitive impairment was found in 7.14% of phenobarbital group and 50.0% in valproate group (P = 0.026). In addition, there were no significant differences with respect to anxiety (36.36% vs. 38.10%) and depression (31.82% vs. 47.62%) between the phenobarbital and valproate groups.
CONCLUSIONS
Combined with long term conventional therapy, intravenous phenobarbital group had more good outcomes than intravenous valproate group in Chinese adult patients with GCSE up to 12-month follow-up. This finding may prompt the option of intravenous phenobarbital especially in patients with limited access to new antiseizure drugs.
Topics: Humans; Adult; Valproic Acid; Anticonvulsants; Follow-Up Studies; Treatment Outcome; Status Epilepticus; Phenobarbital; Diazepam
PubMed: 37467704
DOI: 10.1016/j.eplepsyres.2023.107187 -
Epilepsy & Behavior : E&B Apr 2023Phenobarbital (PB) is one of the oldest Antiseizure Medicines (ASMs), which is in clinical use since 1912. Its value in the treatment of Status epilepticus is currently... (Review)
Review
Phenobarbital (PB) is one of the oldest Antiseizure Medicines (ASMs), which is in clinical use since 1912. Its value in the treatment of Status epilepticus is currently discussed controversially. Phenobarbital has fallen out of favor in many countries across Europe because of reports of hypotension, arrhythmias, and hypopnea. Phenobarbital has a strong antiseizure effect with remarkably little sedation. It exerts its clinical effects, through the increase of GABE-ergic inhibition and decrease of glutamatergic excitation by inhibition of AMPA receptors. Despite good preclinical evidence, there are remarkably few randomized controlled studies on humans in SE, which suggest, that it is at least as good as lorazepam in first-line treatment in early SE, and significantly better than valproic acid in benzodiazepine-resistant SE. Data from randomized trials and large non-randomized prospective and retrospective studies suggest, that Phenobarbital is well tolerated even if used in very high dose protocols. Thus, despite its decline in its popularity at least in Europe and North America, it should be considered a highly cost-effective treatment for early and established SE, not only in resource-limited settings. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.
Topics: Humans; Anticonvulsants; Retrospective Studies; Prospective Studies; Status Epilepticus; Phenobarbital
PubMed: 36807987
DOI: 10.1016/j.yebeh.2023.109104 -
Journal of Investigative Medicine High... 2019Refractory alcohol withdrawal delirium is uncommon in day-to-day clinical practice. This case report presents a rare case of delirium tremens of unusually long duration...
Refractory alcohol withdrawal delirium is uncommon in day-to-day clinical practice. This case report presents a rare case of delirium tremens of unusually long duration that was complicated by the difficulty in tapering down benzodiazepines despite adding midazolam drip as well as phenobarbitone to the management regimen and excluding other possible diagnoses.
Topics: Alcohol Withdrawal Delirium; Benzodiazepines; Brain; Diagnosis, Differential; Humans; Hypnotics and Sedatives; Male; Midazolam; Middle Aged; Phenobarbital; Tomography, X-Ray Computed
PubMed: 31053040
DOI: 10.1177/2324709619847228 -
The Veterinary Record Feb 2017
Topics: Animals; Anticonvulsants; Dog Diseases; Dogs; Drug Administration Schedule; Epilepsy, Generalized; Phenobarbital
PubMed: 28213422
DOI: 10.1136/vr.j705 -
The Cochrane Database of Systematic... Mar 2015The incidence of seizures following supratentorial craniotomy for non-traumatic pathology has been estimated to be between 15% to 20%; however, the risk of experiencing... (Review)
Review
BACKGROUND
The incidence of seizures following supratentorial craniotomy for non-traumatic pathology has been estimated to be between 15% to 20%; however, the risk of experiencing a seizure may vary from 3% to 92% over a five-year period. Postoperative seizures can precipitate the development of epilepsy; seizures are most likely to occur within the first month of cranial surgery. The use of antiepileptic drugs (AEDs) administered pre- or postoperatively to prevent seizures following cranial surgery has been investigated in a number of randomised controlled trials (RCTs).
OBJECTIVES
To determine the efficacy and safety of AEDs when used prophylactically in people undergoing craniotomy and to examine which AEDs are most effective.
SEARCH METHODS
Searches were run for the original review in January 2012. We performed subsequent searches in September 2012 and up to 04 August 2014. We searched the Cochrane Epilepsy Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE. We did not apply any language restrictions.
SELECTION CRITERIA
We included RCTs of people with no history of epilepsy who were undergoing craniotomy for either therapeutic or diagnostic reasons. Trials with adequate randomisation methods and concealment were included; these could either be blinded or unblinded parallel trials. We did not stipulate a minimum treatment period, and we included trials using active drugs or placebo as a control group.
DATA COLLECTION AND ANALYSIS
Two review authors (JP and JG) independently selected trials for inclusion and performed data extraction and risk of bias assessments. We resolved any disagreements through discussion. Outcomes investigated included the number of patients experiencing seizures (early - occurring within first week following craniotomy, and late - occurring after first week following craniotomy), the number of deaths and the number of people experiencing disability and adverse effects. Due to the heterogeneous nature of the trials, we did not combine data from the included trials in a meta-analysis; we presented the findings of the review in narrative format.
MAIN RESULTS
We included eight RCTs (N = 1602), which were published between 1983 and 2013. Three trials compared a single AED (phenytoin) with a placebo or no treatment. One three-arm trial compared two AEDs (carbamazepine, phenytoin) with no treatment. A second three-arm trial compared phenytoin, phenobarbital and no treatment. Three other trials were head-to-head trials of AEDs (phenytoin vs. valproate; zonisamide vs. phenobarbital) and levetiracetam vs. phenytoin. Of the five trials comparing AEDs with controls, only one trial reported a significant difference between AED treatment and controls for early seizure occurrence. All other comparisons were non-significant. Of the head-to-head trials, none reported statistically significant differences between treatments for either early or late seizures. One head-to-head trial showed an increase in the number of deaths following one AED treatment compared to another AED treatment. Incidences of adverse effects of treatment were poorly reported, and the most trials reported no significant differences between treatment groups. However data on adverse events were limited.
AUTHORS' CONCLUSIONS
There is little evidence to suggest that AED treatment administered prophylactically is effective or not effective in preventing post-craniotomy seizures. The current evidence base is limited due to the differing methodologies employed in the trials and inconsistencies in reporting of outcomes. Further evidence from good-quality, contemporary trials is required in order to assess the effectiveness of prophylactic AED treatment compared to control groups or other AEDs in preventing post-craniotomy seizures properly.
Topics: Anticonvulsants; Carbamazepine; Craniotomy; Humans; Isoxazoles; Phenobarbital; Phenytoin; Randomized Controlled Trials as Topic; Seizures; Valproic Acid; Zonisamide
PubMed: 25738821
DOI: 10.1002/14651858.CD007286.pub3 -
Journal of Feline Medicine and Surgery Sep 2023Phenobarbital (PB) q12h is the most common treatment recommendation for cats with recurrent epileptic seizures. Medicating cats may be challenging and result in...
OBJECTIVES
Phenobarbital (PB) q12h is the most common treatment recommendation for cats with recurrent epileptic seizures. Medicating cats may be challenging and result in decreased quality of life for both cat and owner. The aim of this retrospective study was to evaluate treatment with oral PB q24h in cats with presumptive idiopathic epilepsy.
METHODS
Nine cats with presumptive idiopathic epilepsy, receiving oral PB q24h, were included in a retrospective descriptive study.
RESULTS
Seizure remission was achieved in 88% (8/9) of the cats and good seizure control in 12% (1/9) of the cats, treated with a mean dose of oral PB of 2.6 mg/kg q24h (range 1.4-3.8 mg/kg). No cats required an increase of their PB frequency at any time during a mean follow-up period of 3.5 years (range 1.1-8.0 years). No cats displayed side effects or issues with compliance at the last recorded follow-up.
CONCLUSIONS AND RELEVANCE
Once-a-day administration of PB for feline epilepsy was safe and resulted in satisfactory seizure control for the nine cats included in this study. The results of this study justify exploring this topic further in larger prospective studies.
Topics: Cats; Animals; Retrospective Studies; Prospective Studies; Quality of Life; Epilepsy; Seizures; Phenobarbital; Cat Diseases
PubMed: 37747329
DOI: 10.1177/1098612X231196806 -
Addiction (Abingdon, England) Jul 2023Phenobarbital interacts with the mortality-reducing opioid agonist therapies buprenorphine and methadone, risking delayed opioid withdrawal and relapse when administered...
Phenobarbital interacts with the mortality-reducing opioid agonist therapies buprenorphine and methadone, risking delayed opioid withdrawal and relapse when administered concurrently. With increased adoption of phenobarbital into alcohol withdrawal protocols there should be safeguards in place to—in most cases—avoid phenobarbital for patients with a concurrent opioid use disorder.
Topics: Humans; Analgesics, Opioid; Substance Withdrawal Syndrome; Alcoholism; Opioid Epidemic; Buprenorphine; Methadone; Phenobarbital; Opioid-Related Disorders; Opiate Substitution Treatment
PubMed: 36967706
DOI: 10.1111/add.16194 -
The Cochrane Database of Systematic... Nov 2016Any type of seizure can be observed in Alzheimer's disease (AD). Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with AD. There... (Review)
Review
BACKGROUND
Any type of seizure can be observed in Alzheimer's disease (AD). Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with AD. There are pharmacological and non-pharmacological treatments for epilepsy in people with AD. There are no current systematic reviews to evaluate the efficacy and tolerability of the treatment. This review aims to review those different modalities.
OBJECTIVES
To assess the efficacy and tolerability of the treatment of epilepsy for people with Alzheimer's disease (AD) (including sporadic AD and dominantly inherited AD).
SEARCH METHODS
We searched the Cochrane Epilepsy Group Specialized Register (1 February 2016), the Cochrane Central Register of Controlled Trials (1 February 2016), MEDLINE (Ovid, 1 February 2016) and ClinicalTrials.gov (1 February 2016). In an effort to identify further published, unpublished and ongoing trials, we searched ongoing trials' registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies.
SELECTION CRITERIA
We included randomised and quasi-randomised controlled trials investigating treatment for epilepsy in people with AD, with the outcomes of proportion of seizure freedom or experiencing adverse events.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted data, cross-checked the data for accuracy and assessed the methodological quality. We performed no meta-analyses due to the limited available data.
MAIN RESULTS
We included one randomised controlled trial with 95 participants. Concerning the proportion of participants with seizure freedom, no significant differences were found in levetiracetam (LEV) versus lamotrigine (LTG) (risk ratio (RR) 1.20, 95% confidence interval (CI) 0.53 to 2.71), in levetiracetam versus phenobarbital (PB) (RR 1.01, 95% CI 0.47 to 2.19), or in LTG versus PB (RR 0.84, 95% CI 0.35 to 2.02). It seemed that LEV could improve cognition and LTG could relieve depression; while PB and LTG could worsen cognition, and LEV and PB could worsen mood. We judged the quality of the evidence to be very low.
AUTHORS' CONCLUSIONS
This review does not provide sufficient evidence to support LEV, PB and LTG for the treatment of epilepsy in people with AD. Regarding the efficacy and tolerability, no significant differences were found between LEV, PB and LTG. In the future, large randomised, double-blind, controlled, parallel-group clinical trials are required to determine the efficacy and tolerability of treatment for epilepsy in people with AD.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Anticonvulsants; Cognition; Depression; Epilepsy; Female; Humans; Lamotrigine; Levetiracetam; Male; Phenobarbital; Piracetam; Randomized Controlled Trials as Topic; Triazines
PubMed: 27805721
DOI: 10.1002/14651858.CD011922.pub2 -
The Cochrane Database of Systematic... May 2021Any type of seizure can be observed in Alzheimer's disease. Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with Alzheimer's...
BACKGROUND
Any type of seizure can be observed in Alzheimer's disease. Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with Alzheimer's disease. There are pharmacological and non-pharmacological treatments for epilepsy in people with Alzheimer's disease, however there are no current systematic reviews to evaluate the efficacy and tolerability of these treatments. This review aims to investigate these different modalities. This is an updated version of the Cochrane Review previously published in 2018.
OBJECTIVES
To assess the efficacy and tolerability of pharmacological or non-pharmacological interventions for the treatment of epilepsy in people with Alzheimer's disease (including sporadic Alzheimer's disease and dominantly inherited Alzheimer's disease).
SEARCH METHODS
For the latest update, on 3 August 2020 we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 31 July 2020). CRS Web includes randomized or quasi-randomized controlled trials from PubMed, EMBASE, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups, including Cochrane Epilepsy. In an effort to identify further published, unpublished and ongoing trials, we searched ongoing trials registers, reference lists and relevant conference proceedings; we also contacted trial authors and pharmaceutical companies.
SELECTION CRITERIA
We included randomized and quasi-randomized controlled trials investigating treatment for epilepsy in people with Alzheimer's disease, with the primary outcomes of proportion of participants with seizure freedom and proportion of participants experiencing adverse events.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted data, cross-checked the data for accuracy and assessed the methodological quality. We performed no meta-analyses due to there being limited available data.
MAIN RESULTS
We included one randomized controlled trial (RCT) on pharmacological interventions; the trial included 95 participants. No studies were found for non-pharmacological interventions. Concerning the proportion of participants with seizure freedom, no significant differences were found for the comparisons of levetiracetam versus lamotrigine (RR) 1.20, 95% CI 0.53 to 2.71; 67 participants; very low-certainty evidence), levetiracetam versus phenobarbital (RR 1.01, 95% CI 0.47 to 2.19; 66 participants; very low-certainty evidence), or lamotrigine versus phenobarbital (RR 0.84, 95% CI 0.35 to 2.02; 57 participants; very low-certainty evidence). It seemed that levetiracetam could improve cognition and lamotrigine could relieve depression, while phenobarbital and lamotrigine could worsen cognition, and levetiracetam and phenobarbital could worsen mood. The risk of bias relating to allocation, blinding and selective reporting was unclear. We judged the certainty of the evidence for all outcomes to be very low.
AUTHORS' CONCLUSIONS
This review does not provide sufficient evidence to support levetiracetam, phenobarbital or lamotrigine for the treatment of epilepsy in people with Alzheimer's disease. Regarding efficacy and tolerability, no significant differences were found between levetiracetam, phenobarbital and lamotrigine. Large RCTs with a double-blind, parallel-group design are required to determine the efficacy and tolerability of treatment for epilepsy in people with Alzheimer's disease.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Anticonvulsants; Cognition; Depression; Epilepsy; Female; Humans; Lamotrigine; Levetiracetam; Male; Phenobarbital; Randomized Controlled Trials as Topic; Secondary Prevention
PubMed: 33973646
DOI: 10.1002/14651858.CD011922.pub4