Hepatotoxicity associated with antiepileptic drugs

A Cross-Sectional Study Comparing Oxidative Stress in Patients with Epilepsy Treated with Old and New Generation Antiseizure Medications

Background and Objectives: Oxidative stress resulting from a disturbance of the endogenous redox system is suspected in numerous diseases of the central nervous system, including epilepsy. In addition, antiseizure medications (ASMs), especially those of the old generation, may further increase oxidative stress. To evaluate the effects of ASM generation on oxidative stress, we conducted a cross-sectional study in patients with epilepsy treated with old, new, and polytherapy. Materials and Methods: The antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, as well as the concentrations of malondialdehyde, protein carbonyl, nitrate, nitrite, and glutathione in reduced and oxidized forms, were measured in 49 patients with epilepsy and 14 healthy controls. In addition, the plasma concentrations of ASMs and metabolites of carbamazepine and valproic acid were measured in the patients. Results: Patients with epilepsy showed increased activities of superoxide dismutase and catalase (p < 0.001), concentrations of glutathione disulfide and markers of nitric oxide metabolism (p < 0.001), and decreased activities of glutathione peroxidase, glutathione reductase, glutathione, and nitrite concentrations (p ≤ 0.005) compared to healthy controls. A comparison of ASM generations revealed increased levels of superoxide dismutase and catalase (p ≤ 0.007) and decreased levels of glutathione peroxidase and glutathione reductase (p ≤ 0.01) in patients treated with old ASMs compared to those treated with new generation ASMs. In addition, an increase in protein carbonyl and nitric oxide metabolites (p ≤ 0.002) was observed in patients treated with old generation ASMs compared to those treated with new generation ASMs. Most oxidative stress parameters in patients receiving polytherapy with ASMs were intermediate between the results of patients treated with the old and new generations of ASMs. Conclusions: An increase in oxidative stress markers and modulation of antioxidant enzyme activities was observed in patients with epilepsy compared to controls. The results of our study showed significantly higher oxidative stress in patients treated with old ASMs compared to those treated with new generation ASMs.

"Should We Phenobarb-it-All?" A Phenobarbital-Based Protocol for Non-Intensive Care Unit Trauma Patients at High Risk of or Experiencing Alcohol Withdrawal

BACKGROUND

Alcohol use is frequent in trauma patients and alcohol withdrawal syndrome (AWS) is associated with significant morbidity. Benzodiazepines are commonly used for AWS, but may cause neurologic and respiratory adverse events (AEs). The objective was to evaluate the effectiveness and safety of a phenobarbital-based protocol for the treatment of AWS in non-intensive care unit (ICU) trauma patients.

METHODS

Adult non-ICU trauma patients at high risk of or experiencing AWS PRE and POST implementation of a phenobarbital-based protocol were included. Outcomes were AWS-related complications (AWS-RC), benzodiazepine use, adjunctive medication use, hospital length of stay (HLOS), and medication-related AEs. Subgroup analyses were performed on patients with traumatic brain injury (TBI), rib fractures, and at high risk of severe AWS.

RESULTS

Overall, 110 patients were included (51 PRE, 59 POST). AWS-RC developed in 17 PRE patients compared to 10 POST patients (33% vs 17%; P = .05). PRE patients were more likely to receive benzodiazepines (88% vs 42%, P < .0001) and higher total dose (11 vs 4 mg lorazepam equivalent; P = .001). No difference noted in HLOS (8 vs 8 days, P = .27), adjunctive medication use (49% vs 54%, P = .60), or AEs (57% vs 39%, P = .06). There was no difference in AWS-RC in the TBI subgroup (P = .19), less AEs in the rib fracture POST subgroup (P = .04), and less AWS-RC in the high risk of severe AWS POST subgroup (P = .03).

DISCUSSION

A phenobarbital-based protocol in trauma patients is effective in preventing AWS-RC and decreasing benzodiazepine use without increasing AEs.

Status epilepticus resulted in rhabdomyolysis-induced AKI associated with hepatotoxicity induced by synergistic carbamazepine and diazepam: A case report

RATIONALE

Rhabdomyolysis is a serious complication of status epilepticus (SE) caused by muscle cell damage and can lead to a life-threatening acute kidney injury (AKI).

PATIENT CONCERNS

A 35-year-old man with a history of seizures treated with 3 different antiepileptic drugs (carbamazepine, lamotrigine, and levetiracetam) presented with SE. The patient received 5 doses of diazepam to control the SE in another hospital and was transferred to our emergency due to AKI.

DIAGNOSES

Laboratory tests corresponded with rhabdomyolysis-induced AKI and disseminated intravascular coagulation. Thereafter, the decrease in renal excretion of both drugs (diazepam and carbamazepine) caused acute liver injury and neurotoxicity. The carbamazepine concentration was 16.39 mcg/mL, which considered in toxic level, despite using the usual dose.

INTERVENTIONS

The patient was treated with hydration and sodium bicarbonate, however; severe AKI mandated a hemodialysis session.

OUTCOMES

The diuresis started to increase, kidney and liver functions improved, and altered mental status reversed.

LESSONS

This case alerts physicians to consider the synergistic drug side effects and interactions, especially when patients present with impaired liver or kidney functions. The reduction in metabolism or excretion of drugs can cause an increase in serum concentrations and induce toxicity, even when the drug intake at the usual dose.

Concurrent administration of farnesol protects acetaminophen-induced acute hepatic necrosis in mice

Acetaminophen (APAP) is known to cause acute liver injury and acute liver failure in Western countries. This study investigates the protective role of farnesol (FAR) (C15 H26 O), a natural sesquiterpene alcohol in essential oils, against APAP-induced acute liver necrosis in mice. Mice were injected with a single dose of APAP (300 mg/kg) via an intraperitoneal route. Different groups of mice were concurrently treated with a single dose of FAR 25 mg/kg, FAR 50 mg/kg, and N-acetylcysteine. APAP administration caused a significant increase in transaminase activities and malondialdehyde (MDA) levels in the serum and liver tissue, respectively, with a concomitant decrease in intracellular antioxidants, including reduced glutathione (GSH) in the liver tissue. APAP intoxication upregulated proinflammatory cytokines such as tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, nuclear factor-κB (NF-κB), and IκB kinase β in the liver tissue. FAR and N-acetylcysteine (NAC) administrations concurrently with APAP prevented serum transaminase increase in serum and MDA levels in the liver tissue. A high dose of FAR and NAC treatments significantly inhibited GSH and other antioxidant depletion. FAR and NAC treatments also downregulated the expression of proinflammatory markers. FAR treatments protects against APAP-induced acute liver injury and offers antioxidant and anti-inflammatory effects by inhibiting the NF-κB pathway involved in the transcription of genes responsible for inflammatory cytokine synthesis.

Black-Box Warnings of Antiseizure Medications: What is Inside the Box?

Antiseizure medications can cause serious adverse reactions and have deleterious drug interactions that often complicate the clinical management of patients. When the US Food and Drug Administration (FDA) wants to alert healthcare providers and patients about the risk of potentially serious or fatal drug reactions, the FDA requires the manufacturers of these medications to format these warnings within a "black-box" border, and prominently display this box on the first section of the package insert; such warnings are called "black-box warnings (BBWs)". The BBW is a way for the FDA to urge physicians to evaluate patients more rigorously and carefully weigh the risks and benefits, before prescribing medication that has the potential to cause serious adverse reactions, and to formulate a plan for close monitoring during therapy. The FDA BBW provides the extra layer of safety but many healthcare providers fail to comply with these warnings. Currently, there are 26 FDA-approved antiseizure medications in the US market, 38% of which have received BBWs, and most of the antiseizure medications with BBWs are older-generation drugs. Some antiseizure medications have multiple BBWs; for example, valproic acid has three BBWs including hepatotoxicity, fetal risk, and pancreatitis, carbamazepine has BBWs of serious skin and hematological reactions, and felbamate also has two BBWs including hepatic failure and aplastic anemia. The purpose of this review is to provide insight into each BBW received by antiseizure medications and discuss the FDA recommendations for evaluating the drug benefit/risk, and for monitoring parameters before the initiation of and during treatment.

The Impact of Epilepsy on Complication Rates After Total Joint Arthroplasty: A Propensity Score-Matched Cohort Study

BACKGROUND

It is unclear how epilepsy may affect total joint arthroplasty outcomes. The purpose of this study is to analyze the impact of epilepsy on prosthesis-related complications following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

A retrospective cohort study was conducted using a national database. Patients who have epilepsy underwent a primary THA (n = 6,981) and TKA (n = 4,987) and were matched 1:4 (THA, n = 27,924; TKA, n = 19,948). Rates of low-energy falls and prosthesis-related complications within 2 years postoperatively were compared for patients who did and did not have epilepsy with multivariable logistic regression.

RESULTS

After primary TKA, patients who have epilepsy exhibited significantly higher rates of aseptic revision (4.3% versus 3.5%, odds ratio [OR] 1.21, P = .017) and revision for prosthetic joint infection (1.8% versus 1.3%, OR 1.29, P = .041). THA patients who have epilepsy exhibited significantly higher rates of prosthetic dislocation (3.2% versus 1.9%, OR 1.54, P < .001), periprosthetic fracture (2.2% versus 0.8%, OR 2.39, P < .001), and aseptic loosening (1.7% versus 1.1%, OR 1.40, P = .002). Rates of low-energy falls within 2 years after TKA (14.1% versus 6.4%, OR 2.19, P < .001) and THA (33.6% versus 7.5%, OR 5.95, P < .001) were also significantly higher for patients who have epilepsy.

CONCLUSION

Epilepsy was associated with significantly higher rates of falls (P < .001) and prosthesis-related complications after primary THA (P < .05) and TKA (P < .05). Precautions should be implemented in this population during intraoperative and perioperative decision-making to reduce complication risk.

LEVEL OF EVIDENCE

Level III.

Potential risk of liver injury in epileptic patients during COVID-19 pandemic

Most of the antiseizure medications (ASMs) are metabolized in liver and many of them particularly first-generation ASMs have the potential to increase liver enzymes or induce liver injury. Hence, treatment of new onset seizures or epilepsy by ASMs during the course of coronavirus disease 2019 (COVID-19), which could potentially be complicated by hepatic dysfunction, is a challenging clinical issue. Intravenous form of levetiracetam which has no significant hepatic metabolism or drug-drug interaction is often a favorable option to control seizures in acute phase of COVID-19. Administration of enzyme inducer ASMs and valproate with the well-known hepatotoxicity and common drug interactions is not generally recommended. In patients with epilepsy who are under control with potentially hepatotoxic ASMs, close observation and cautious dose reduction or drug switch should be considered if any evidence of hepatic impairment exists. However, risks of possible breakthrough seizures should be weighed against benefits of lowering the hazard of liver injury. In patients with epilepsy who receive polytherapy with ASMs, transient dose modification with the tendency to increase the dose of ASMs with more favorable safety profile and less drug interaction and decrease the dose of drugs with main hepatic metabolism, high protein binding, potential to cause liver injury and known drug-drug reaction should be considered. Finally, decision making should be individualized based on patients' conditions and course of illness.

Long-Term Effects of Antiseizure Medications

Most patients with epilepsy will benefit from seizure control with one of an array of chronic antiseizure medications. Knowledge of the potential long-term effects of these medications is critical to prevent adverse consequences on overall health. Antiseizure medications vary in their capacities to affect the brain and peripheral nerves, hormones, bone mineralization, cardiovascular risk, renal health, hepatic, hematological, and dermatological systems. Understanding of pathophysiology and population risk has evolved, although most of the data available are still on older generation antiseizure medications such as phenytoin, carbamazepine, and valproic acid. The enzyme-inducing properties of some antiseizure medications make their effects on cardiovascular risk and bone health detrimental. Few clear guidelines exist for monitoring long-term effects of medication therapy for epilepsy. When selecting an antiseizure medication, consideration should be given to the individual patient's risks of adverse consequences on other organ systems. During monitoring of patients on chronic therapy, screening tools such as metabolic panels and bone density measurements can help stratify risk and guide management.

Glucocorticoid Treatment Strategies in Liver Failure

Liver failure is characterized by serious liver decompensation and high mortality. The activation of systemic immune responses and systemic inflammation are widely accepted as the core pathogenesis of liver failure. Glucocorticoids (GCs) are most regularly utilized to suppress excessive inflammatory reactions and immunological responses. GCs have been used in the clinical treatment of liver failure for nearly 60 years. While there has been no unanimity on the feasibility and application of GC treatment in liver failure until recently. The most recent trials have produced conflicting results when it comes to the dose and time for GC therapy of different etiology of liver failure. Our review outlines the issues and options in managing GC treatment in liver failure based on an investigation of the molecular mechanism that GC may give in the treatment.

Assessment of hepatic prostaglandin E2 level in carbamazepine induced liver injury

Objective. Carbamazepine (CBZ), a widely used antiepileptic drug, is one major cause of the idiosyncratic liver injury along with immune reactions. Conversely, prostaglandin E₂ (PGE2) demonstrates a hepatoprotective effect by regulating immune reactions and promoting liver repair in various types of liver injury. However, the amount of hepatic PGE₂ during CBZ-induced liver injury remains elusive. In this study, we aimed to evaluate the hepatic PGE₂ levels during CBZ-induced liver injury using a mouse model. Methods. Mice were orally administered with CBZ at a dose of 400 mg/kg for 4 days, and 800 mg/kg on the 5th day. Results. Plasma alanine transaminase (ALT) level increased in some of mice 24 h after the last CBZ administration. Although median value of hepatic PGE₂ amount in the CBZ-treated mice showed same extent as vehicle-treated control mice, it exhibited significant elevated level in mice with severe liver injury presented by a plasma ALT level >1000 IU/L. According to these results, mice had a plasma ALT level >1000 IU/L were defined as responders and the others as non-responders in this study. Even though, the hepatic PGE₂ levels increased in responders, the hepatic expression and enzyme activity related to PGE₂ production were not upregulated when compared with vehicle-treated control mice. However, the hepatic 15-hydroxyprostaglandin dehydrogenase (15-PGDH) expression and activity decreased significantly in responders when compared with control mice. Conclusions. These results indicate that elevated hepatic PGE₂ levels can be attributed to the downregulation of 15-PGDH expression under CBZ-induced liver injury.

Correlation between Level of Serum Transaminases and Duration of Antiepileptic Drugs in Epilepsy Children in Sanglah Hospital

BACKGROUND: Some antiepileptic drugs (AEDs), particularly sodium valproate, phenytoin, phenobarbital, and carbamazepine induce and increase production of hepatic enzymes. The adverse metabolic effects of AEDs treatments have become main concern, however data about evaluation of serum transaminases and duration of AEDs in Indonesia still limited. AIM: The aim of the study was to investigate correlation of AEDs and serum transaminases in children with epilepsy. METHODS: This cross-sectional research was conducted in pediatric neurology outpatient clinic in Sanglah Hospital. The target was children with epilepsy who had taken AEDs for at least 6 months. Data were collected from January 2020 to the number of samples were achieved. The exclusion criteria were concomitant liver disease, taking drugs which induce elevated serum transaminase or alcohol abuse. Data including age, gender, nutritional status, type, and duration of AEDs were obtained from medical record. Correlation was analyzed by Pearson’s or Spearman’s correlation, p < 0.05 was considered significant. RESULTS: Total 148 epileptic children enrolled in this study. Aspartate transaminase (AST) and alanine aminotransferase (ALT) level were highest in the group receiving combination therapy (34.37 ± 24.9 U/L and 35.96 ± 23.3 U/L). There was a significant negative correlation between duration of carbamazepine and AST (r = –0.723, p = 0.0001) and ALT (r = –0.457, p = 0.009), as well as duration of valproic acid with AST and ALT (r = –0.689 and –0.677, p = 0.0001). Duration of phenobarbital administration was positively correlated with AST and ALT (r = 0.546 and 0.425, p = 0.0001). Combination therapy also had positive correlation with AST and ALT (r = 0.815 and 0.781, p = 0.0001, respectively). CONCLUSION: Duration administration of carbamazepine and valproic acid had negative correlation with AST and ALT; however, phenobarbital and combination therapy were positively correlated with AST and ALT.

A potential implication of UDP-glucuronosyltransferase 2B10 in the detoxification of drugs used in pediatric hematopoietic stem cell transplantation setting: an in silico investigation

Background

Sinusoidal occlusion syndrome (SOS) is a potentially severe complication following hematopoietic stem cell transplantation (HSCT) in pediatric patients. Treatment related risk factors such as intensity of conditioning, hepatotoxic co-medication and patient related factors such as genetic variants predispose individuals to develop SOS. The variant allele for SNP rs17146905 in UDP-glucuronosyl transferase 2B10 (UGT2B10) gene was correlated with the occurrence of SOS in an exome-wide association study. UGT2B10 is a phase II drug metabolizing enzyme involved in the N-glucuronidation of tertiary amine containing drugs.

Methods

To shed light on the functionality of UGT2B10 enzyme in the metabolism of drugs used in pediatric HSCT setting, we performed in silico screening against custom based library of putative ligands. First, a list of potential substrates for in silico analysis was prepared using a systematic consensus-based strategy. The list comprised of drugs and their metabolites used in pediatric HSCT setting. The three-dimensional structure of UGT2B10 was not available from the Research Collaboratory Structural Bioinformatics - Protein Data Bank (RCSB - PDB) repository and thus we predicted the first human UGT2B10 3D model by using multiple template homology modeling with MODELLER Version 9.2 and molecular docking calculations with AutoDock Vina Version 1.2 were implemented to quantify the estimated binding affinity between selected putative substrates or ligands and UGT2B10. Finally, we performed molecular dynamics simulations using GROMACS Version 5.1.4 to confirm the potential UGT2B10 ligands prioritized after molecular docking (exhibiting negative free binding energy).

Results

Four potential ligands for UGT2B10 namely acetaminophen, lorazepam, mycophenolic acid and voriconazole n-oxide intermediate were identified. Other metabolites of voriconazole satisfied the criteria of being possible ligands of UGT2B10. Except for bilirubin and 4-Hydroxy Voriconazole, all the ligands (particularly voriconazole and hydroxy voriconazole) are oriented in substrate binding site close to the co-factor UDP (mean ± SD; 0.72 ± 0.33 nm). Further in vitro screening of the putative ligands prioritized by in silico pipeline is warranted to understand the nature of the ligands either as inhibitors or substrates of UGT2B10.

Conclusions

These results may indicate the clinical and pharmacological relevance UGT2B10 in pediatric HSCT setting. With this systematic computational methodology, we provide a rational-, time-, and cost-effective way to identify and prioritize the interesting putative substrates or inhibitors of UGT2B10 for further testing in in vitro experiments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-021-00402-5.

Influence of nanoparticle size on blood-brain barrier penetration and the accumulation of anti-seizure medicines in the brain

Anti-seizure medicines constitute a common yet important modality to treat epilepsy. However, some of them are associated with serious side effects including hepatotoxicity and hypersensitivity. Furthermore, the blood-brain barrier (BBB) is an insurmountable obstacle for brain drug delivery. Fortunately, the introduction of the nanoparticles for drug delivery is a feasible approach to overcome these obstacles. Encapsulating drugs into nanoparticles and delivering them to specific sites shows great potential for improving the efficiency of drug delivery and reducing systemic toxicity. Several in vivo studies have investigated the effect of nanoparticle size on biodistribution in mice, but very few have investigated its effects on efficient drug delivery while crossing the BBB. Therefore, we designed a methoxy poly(lactide-co-glycolide)-b-poly(ethylene glycol) methyl ether (mPEG-PLGA) nanoparticle delivery system and explored the cell uptake efficiency of nanoparticles with different sizes and their ability to penetrate the BBB while carrying carbamazepine (CBZ). CBZ-loaded nanoparticles could significantly reduce the cytotoxicity of CBZ to L929 cells at high concentrations. Results from the endocytosis experiment involving human cerebral microvessel endothelial cell/D3 showed that the DiR-loaded mPEG_5K-PLGA_10K nanoparticles possessed the highest cell uptake efficiency. The endocytosis efficiency was 90% at 30 min, which far exceeded that of the other groups. Moreover, similar results were obtained from subsequent experiments where fluorescence images of the isolated organs of the mice were acquired. To summarize, our study demonstrated that drug delivery to the brain using nanocarriers is size dependent. Nanoparticles with the smallest particle size can be internalized more effectively, and easily penetrate the BBB, and accumulate in the brain.

Prevalence of Congenital Disorders of Glycosylation in Childhood Epilepsy and Effects of Anti-Epileptic Drugs on the Transferrin Isoelectric Focusing Test

Introduction: Childhood epilepsy is one of the most common neurological problems. The transferrin isoelectric focusing (TIEF) test is a screening test for congenital disorders of glycosylation (CDG). We identified abnormal TIEF test in children with epilepsy in our epilepsy genetics clinic. To determine if an abnormal TIEF test is associated with anti-epileptic medications or abnormal liver functions, we performed a retrospective cohort study. Methods: This study was performed between January 2012 and March 2020. Electronic patient charts were reviewed. Standard non-parametric statistical tests were applied using R statistical software. Fischer’s exact test was used for comparisons. Results: There were 206 patients. The TIEF test was abnormal in 11% (23 out of 206) of the patients. Nine patients were diagnosed with CDG: PMM2-CDG (n = 5), ALG3-CDG (n = 1), ALG11-CDG (n = 2), SLC35A2-CDG (n = 1). We report 51 different genetic diseases in 84 patients. Two groups, (1) abnormal TIEF test; (2) normal TIEF test, showed statistically significant differences for abnormal liver functions and for valproic acid treatment. Conclusion: The TIEF test guided CDG diagnosis in 2.9% of the patients. Due to the high prevalence of CDG (4.4%) in childhood epilepsy, the TIEF test might be included into the diagnostic investigations to allow earlier and cost-effective diagnosis.

Carbamazepine induces hepatotoxicity in zebrafish by inhibition of the Wnt/β-catenin signaling pathway

As drug abuse has become increasingly serious, carbamazepine (CBZ) is discharged into the aquatic environment with municipal sewage, causing potential harm to aquatic organisms. Here, we utilized zebrafish, an aquatic vertebrate model, to comprehensively evaluate the hepatotoxicity of CBZ. The larvae were exposed to 0.07, 0.13, and 0.26 mmol/L CBZ from 72 hpf to 144 hpf, and the adults were exposed to 0.025, 0.05, and 0.1 mmol/L CBZ for 28 days. The substantial changes were observed in the size and histopathology of livers, indicating that CBZ induced severe hepatoxicity in the larvae and adults. Oil red O staining demonstrated CBZ exposure caused severe lipid accumulation in the livers of both larvae and adults. Furthermore, CBZ exposure facilitated hepatocyte apoptosis through TUNEL staining, which was caused by rising ROS content. Subsequently, down-regulation of genes related to the Wnt pathway in exposure groups indicated that CBZ inhibited the development of liver via the Wnt/β-catenin signaling pathway. In conclusion, CBZ induced severe hepatotoxicity by promoting lipid accumulation, generating excessive ROS production, and inhibiting the Wnt/β-catenin signaling pathway in zebrafish. The results reveal the occurrence of CBZ-induced hepatotoxicity in zebrafish and clarify its mechanism of action, which potentially illustrate environmental concerns associated with CBZ exposure.

Drug-induced liver injury associated with antiseizure medications from the FDA Adverse Event Reporting System (FAERS)

PURPOSE

Treatment with antiseizure medications (ASMs) confers a risk of drug-induced liver injury (DILI), especially for older ASMs. We sought to quantify recent reports of DILI attributed to both older and newer generation ASMs and survey newly marketed ASMs for hepatotoxicity in a large post-marketing database.

METHODS

We queried over 2.6 million adverse event reports made to the FDA Adverse Event Reporting System (FAERS) database between July 1, 2018 and March 31, 2020 for DILI due to ASMs commonly used in clinical practice. Patient characteristics and outcomes were assessed. We calculated the reporting odds ratio (ROR) of DILI for each individual ASM versus all non-ASM reports.

RESULTS

A total of 2175 DILI cases were attributed to an ASM during the study period. 97.2% of these were designated as serious reactions, which include death, hospitalization, disability, and other life-threatening outcomes. A number of older and newer generation ASMs were associated with DILI, specifically: carbamazepine (ROR 2.92), phenobarbital (ROR 2.91), oxcarbazepine (ROR 2.58), phenytoin (ROR 2.40), valproate (ROR 2.22), lamotrigine (ROR 2.06), clobazam (ROR 1.67), levetiracetam (ROR 1.56), and diazepam (ROR 1.53). However, increased odds of DILI were not seen with zonisamide, perampanel, stiripentol, lacosamide, clonazepam, pregabalin, felbamate, eslicarbazepine, cannabidiol, topiramate, gabapentin, ethosuximide, brivaracetam, or primidone. Vigabatrin, tiagabine, and rufinamide all had zero reports of DILI.

CONCLUSIONS

The majority of newer generation ASMs were not significantly associated with DILI. Future studies utilizing FAERS in conjunction with other data sources will be critical for the ongoing surveillance of DILI, particularly as newly marketed ASMs continue to enter into widespread clinical use.

Evidence of drug-induced hepatotoxicity in the Maghrebian population

Drug-induced hepatotoxicity is one of the most challenging hepatic diseases faced nowadays due to a large number of drugs currently used in clinical practice, the enormous dietary supplements which are potentially hepatotoxic, as well as the ability to appear with different clinical symptoms and the absence of specific markers. The current research survey was conducted to investigate drug-induced hepatotoxicity and demographic characteristics of patients with liver damage in the general Maghrebian population between 1992 and 2018. To achieve this goal a questionnaire was adopted to report details on the undesirable effects of drugs and demographic characteristics of affected patients. The results obtained in the current survey showed that 1001 in 25 093 cases of drug-induced toxicity were registered with drug-induced liver damage between 1992 and 2018. Regarding demographic characteristics of affected patients, the most affected age group was 18 to 44-years-old with a percentage of 45.70% followed by the age group 45 to 64-year-old with a percentage of 27.20%. Females were the most frequently affected by the hepatic side effects of drugs vs. males. Paracetamol, isoniazid, rifampicin, and pyrazinamide were the main responsible drugs for liver damage in the study population. Alteration of biological parameters and subclinical phenomena were used as clinical manifestations of liver damage in the study population. The outcome of the present study suggests paying more attention to drugs used for medication and the involvement of rigorous clinical monitoring to prevent or to minimize the side effects of drugs.

S(+)-(2E)-N-(2-Hydroxypropyl)-3-Phenylprop-2-Enamide (KM-568): A Novel Cinnamamide Derivative with Anticonvulsant Activity in Animal Models of Seizures and Epilepsy

Epilepsy is one of the most frequent neurological disorders affecting about 1% of the world’s human population. Despite availability of multiple treatment options including antiseizure drugs, it is estimated that about 30% of seizures still remain resistant to pharmacotherapy. Searching for new antiseizure and antiepileptic agents constitutes an important issue within modern medicinal chemistry. Cinnamamide derivatives were identified in preclinical as well as clinical studies as important drug candidates for the treatment of epilepsy. The cinnamamide derivative presented here: S(+)-(2E)-N-(2-hydroxypropyl)-3-phenylprop-2-enamide (S(+)-N-(2-hydroxypropyl)cinnamamide, compound KM-568) showed anticonvulsant activity in several models of epilepsy and seizures in mice and rats. It was active in a genetic animal model of epilepsy (Frings audiogenic seizure-susceptible mouse model, ED₅₀ = 13.21 mg/kg, i.p.), acute seizures induced electrically (maximal electroshock test ED₅₀ = 44.46 mg/kg mice i.p., ED₅₀ = 86.6 mg/kg mice p.o., ED₅₀ = 27.58 mg/kg rats i.p., ED₅₀ = 30.81 mg/kg rats p.o., 6-Hz psychomotor seizure model 32 mA ED₅₀ = 71.55 mg/kg mice i.p., 44 mA ED₅₀ = 114.4 mg/kg mice i.p.), chronic seizures induced electrically (corneal kindled mouse model ED₅₀ = 79.17 mg/kg i.p., hippocampal kindled rat model ED₅₀ = 24.21 mg/kg i.p., lamotrigine-resistant amygdala kindled seizure model in rats ED₅₀ = 58.59 mg/kg i.p.), acute seizures induced chemically (subcutaneous metrazol seizure threshold test ED₅₀ = 104.29 mg/kg mice i.p., ED₅₀ = 107.27 mg/kg mice p.o., ED₅₀ = 41.72 mg/kg rats i.p., seizures induced by picrotoxin in mice ED₅₀ = 94.11 mg/kg i.p.) and the pilocarpine-induced status epilepticus model in rats (ED₅₀ = 279.45 mg/kg i.p., ED₉₇ = 498.2 mg/kg i.p.). The chemical structure of the compound including configuration of the chiral center was confirmed by NMR spectroscopy, LC/MS spectroscopy, elemental analysis, and crystallography. Compound KM-568 was identified as a moderately stable derivative in an in vitro mouse liver microsome system. According to the Ames microplate format mutagenicity assay performed, KM-568 was not a base substitution or frameshift mutagen. Cytotoxicity evaluation in two cell lines (HepG2 and H9c2) proved the safety of the compound in concentrations up to 100 µM. Based on the results of anticonvulsant activity and safety profile, S(+)-(2E)-N-(2-hydroxypropyl)-3-phenylprop-2-enamide could be proposed as a new lead compound for further preclinical studies on novel treatment options for epilepsy.

Possible Pathways of Hepatotoxicity Caused by Chemical Agents

BACKGROUND

Liver injury induced by drugs has become a primary reason for acute liver disease and therefore posed a potential regulatory and clinical challenge over the past few decades and has gained much attention. It also remains the most common cause of failure of drugs during clinical trials. In 50% of all acute liver failure cases, drug-induced hepatoxicity is the primary factor and 5% of all hospital admissions.

METHODS

The various hepatotoxins used to induce hepatotoxicity in experimental animals include paracetamol, CCl4, isoniazid, thioacetamide, erythromycin, diclofenac, alcohol, etc. Among the various models used to induce hepatotoxicity in rats, every hepatotoxin causes toxicity by different mechanisms.

RESULTS

The drug-induced hepatotoxicity caused by paracetamol accounts for 39% of the cases and 13% hepatotoxicity is triggered by other hepatotoxic inducing agents.

CONCLUSION

Research carried out and the published papers revealed that hepatotoxins such as paracetamol and carbon- tetrachloride are widely used for experimental induction of hepatotoxicity in rats.

Non-Dose-Dependent Changes in Liver Enzyme Levels of Children With Epilepsy on Treatment With Sodium Valproate

Background:

Sodium valproate (VPA) is considered as the drug of choice for the treatment of generalized epilepsy in children. Sodium Valproate may be hepatotoxic.

Aim:

To assess the level of derangement of liver enzymes in children with epilepsy on treatment with sodium valproate.

Methods:

A cohort study. One hundred fifty-three children, comprising 51 with epilepsy on treatment with VPA (group I), 51 with epilepsy on treatment with other antiepileptic drugs (AEDs) but not VPA (group II), and 51 with nonconvulsive disorders (group III) had liver function tests performed for them. Data were analyzed by SPSS version 23.0.

Results:

There were 85 males and 68 females, aged 6 months to 14 years (median = 7.0 years). There was no significant difference in the mean plasma levels of alanine transaminase (ALT), alkaline phosphatase, and gamma glutamyl transferase across the three groups of children. The mean aspartate transaminase level was significantly higher in children in group III. There was a statistically significant negative correlation between the duration of AED therapy and the mean serum level of AST (r = −0.266, P = 0.016). The serum ALT level showed a statistically significant positive correlation with the duration of AED therapy (r = 0.268, P = 0.015).

Conclusion:

Sodium valproate monotherapy does not appear to be associated with significant hepatotoxicity in children in our cohort.

Drug-Induced Liver Injury in Critically Ill Children Taking Antiepileptic Drugs: A Retrospective Study

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Critically ill children on anti-epileptic drugs often receive multiple concomitant drugs with potential to result in liver injury.

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Antimicrobial drugs followed by drugs for stress ulcer prophylaxis form the major drug classes with the risk of DILI that are concomitantly administered with anti-epileptic drugs in critically ill children.

Background

Antiepileptic drugs are among the leading causes of drug-induced liver injury (DILI). Due to critical illness, children admitted to intensive care units are more prone to DILI.

Objective

We attempted to elucidate the association between antiepileptic drug use and the associated factors resulting in DILI in a pediatric intensive care unit of a tertiary care hospital.

Methods

We carried out an observational retrospective study on children receiving antiepileptic drugs. Details on their demographic characteristics, drugs, serum levels of antiepileptic drugs and liver function tests, and hospital stay were recorded. Council for International Organizations of Medical Sciences definitions were adhered to when defining DILI. LiverTox (https://livertox.nih.gov) and DILIrank were used to assess the risks of hepatotoxicity of the concomitant drugs. Regression models were developed for predicting DILI.

Results

Five out of 9 patients taking phenobarbitone (55.6%), 9 out of 12 taking phenytoin monotherapy (75%), 7 out of 10 taking phenytoin/phenobarbitone (70%), all 3 receiving phenytoin/phenobarbitone/valproate sodium, and 1 with phenytoin/carbamazepine developed DILI either in the form of hepatocellular injury or liver biochemical test abnormalities. None of the patients had cholestatic or mixed type of liver injury. All the critically ill children received at least 2 concomitant drugs with hepatotoxic potential. Concomitant category B hepatotoxic drugs and toxic drug levels were significantly associated with increased risk of DILI. Similarly, a trend was observed for less-DILI-concern concomitant drug class and toxic drug levels when the drugs were analyzed by DILIrank classification.

Conclusions

A significant proportion of critically ill children taking antiepileptic drugs experience DILI. Guidelines recommending use of drugs with reduced risk of potential hepatotoxicity for various concomitant disease states in such children admitted to intensive care units receiving antiepileptic drugs are urgently needed.

Preoperative 5-aminolevulinic acid administration for brain tumor surgery is associated with an increase in postoperative liver enzymes: a retrospective cohort study

BACKGROUND

Besides 5-aminolevulinic acid (5-ALA), liver enzyme elevation after brain tumor surgery can be caused by anesthesia and medications. In this retrospective study, we determined whether preoperative 5-ALA administration is associated with postoperative elevation of liver enzymes (PELE) in brain tumor patients and identified predictive factors for PELE in patients treated with 5-ALA.

METHODS

In 179 patients undergoing brain tumor surgery with preoperative normal values of liver enzymes, laboratory data on serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total bilirubin (T.bil) levels were collected preoperatively and through postoperative day (POD) 45.

RESULTS

Ninety-nine PELEs (ALT, 56; AST, 34; ALP, 5; and TB, 4) were observed in 62 (34.6%) patients. Four (4.2%) patients treated with 5-ALA showed grade 3 elevation of transaminases based on the Common Terminology Criteria for Adverse Effects. Preoperative 5-ALA treatment was predictive of PELE (odds ratio [95% confidence interval], 2.30 [1.14-4.67]; P = 0.021). In patients treated with 5-ALA (n = 95), 70 PELEs (ALT, 39; AST, 22; ALP, 5; and TB, 4) were observed in 41 (43.2%) patients and significant predictive factors for PELE were preoperative ALT level (1.10 [1.04-1.17]; P = 0.001) and body mass index (BMI, 1.29 [1.08-1.56]; P = 0.006). In patients treated with 5-ALA, 13 and 36 patients, of 39 patients whose maximum postoperative ALT levels > 40 U/L, showed the normal value of serum ALT on PODs 14 and 45, respectively. Only three patients showed ALT elevation > 40 U/L on PODs 15-45, with a downward trend.

CONCLUSIONS

The use of 5-ALA for brain tumor surgery in patients with preoperative normal values of liver enzymes was associated with increased transient PELE, but a low incidence of severely elevated liver transaminases levels. When 5-ALA is administered to patients with the upper normal value of preoperative serum ALT and overweight, attention is paid to PELE.

The Management of Glucocorticoid Therapy in Liver Failure

Liver failure is characterized by rapid progression and high mortality. Excessive systemic inflammation is considered as the trigger of liver failure. Glucocorticoids (GCs) can rapidly suppress excessive inflammatory reactions and immune response. GCs have been applied in the treatment of liver failure since the 1970s. However, until now, the use of GCs in the treatment of liver failure has been somewhat unclear and controversial. New research regarding the molecular mechanisms of GCs may explain the controversial actions of GCs in liver failure. More results should be confirmed in a larger randomized clinical trial; this can aid the discovery of better definitions in terms of treatment schedules according to different clinical settings. Meanwhile, the timing and dosing of GCs in the treatment of liver failure should also be explored.

EASL Clinical Practice Guidelines: Drug-induced liver injury

Idiosyncratic (unpredictable) drug-induced liver injury is one of the most challenging liver disorders faced by hepatologists, because of the myriad of drugs used in clinical practice, available herbs and dietary supplements with hepatotoxic potential, the ability of the condition to present with a variety of clinical and pathological phenotypes and the current absence of specific biomarkers. This makes the diagnosis of drug-induced liver injury an uncertain process, requiring a high degree of awareness of the condition and the careful exclusion of alternative aetiologies of liver disease. Idiosyncratic hepatotoxicity can be severe, leading to a particularly serious variety of acute liver failure for which no effective therapy has yet been developed. These Clinical Practice Guidelines summarize the available evidence on risk factors, diagnosis, management and risk minimization strategies for drug-induced liver jury.

Research Progress on the Animal Models of Drug-Induced Liver Injury: Current Status and Further Perspectives

Drug-induced liver injury (DILI) is a major concern in clinical studies as well as in postmarketing surveillance. It is necessary to establish an animal model of DILI for thorough investigation of mechanisms of DILI and searching for protective medications. This article reviews the current status and future perspective on establishment of DILI models based on different hepatotoxic drugs, as well as the underlying mechanisms of liver function damage induced by specific medicine. Therefore, information from this article can help researchers make a suitable selection of animal models for further study.

Carbamazepine adverse drug reactions

INTRODUCTION

Carbamazepine (CBZ) is used for the treatment of epilepsy and other neurological and psychiatric disorders. The occurrence of adverse reactions (ADRs) to CBZ can negatively impact the quality of life of patients, as well as increase health-care costs. Thus, knowledge of CBZ-induced ADRs is important to achieve safer treatment outcomes. Areas covered: This review describes the clinical features, known mechanisms, and clinical management of the main CBZ-induced ADRs. In addition, pharmacogenetic studies focused on ADRs induced by CBZ are cited. Expert commentary: CBZ-induced ADRs are well known in the literature. The metabolite CBZ-10,11-epoxide plays an important role in the mechanism that underlies the ADRs induced by CBZ. Several factors should be considered for a safer use of CBZ, such as monotherapy prescription when possible, an adequate dose titration, knowledge of previous ADRs in the patient, and routine monitoring of CBZ plasma concentrations in symptomatic patients. Pharmacogenetics is a potential tool for CBZ therapy improvement, and the design of multicenter studies focused on the identification of biomarkers for CBZ-induced ADRs could provide useful information for a safer CBZ therapy.

Mitochondrial dysfunction as a mechanism of drug-induced hepatotoxicity: current understanding and future perspectives

Mitochondria are critical cellular organelles for energy generation and are now also recognized as playing important roles in cellular signaling. Their central role in energy metabolism, as well as their high abundance in hepatocytes, make them important targets for drug-induced hepatotoxicity. This review summarizes the current mechanistic understanding of the role of mitochondria in drug-induced hepatotoxicity caused by acetaminophen, diclofenac, anti-tuberculosis drugs such as rifampin and isoniazid, anti-epileptic drugs such as valproic acid and constituents of herbal supplements such as pyrrolizidine alkaloids. The utilization of circulating mitochondrial-specific biomarkers in understanding mechanisms of toxicity in humans will also be examined. In summary, it is well-established that mitochondria are central to acetaminophen-induced cell death. However, the most promising areas for clinically useful therapeutic interventions after acetaminophen toxicity may involve the promotion of adaptive responses and repair processes including mitophagy and mitochondrial biogenesis, In contrast, the limited understanding of the role of mitochondria in various aspects of hepatotoxicity by most other drugs and herbs requires more detailed mechanistic investigations in both animals and humans. Development of clinically relevant animal models and more translational studies using mechanistic biomarkers are critical for progress in this area.

Relevance for patients:This review focuses on the role of mitochondrial dysfunction in liver injury mechanisms of clinically important drugs like acetaminophen, diclofenac, rifampicin, isoniazid, amiodarone and others. A better understanding ofthe mechanisms in animal models and their translation to patients will be critical for the identification of new therapeutic targets.

Role of cytochrome P450-mediated metabolism and involvement of reactive metabolite formations on antiepileptic drug-induced liver injuries

Several drugs have been withdrawn from the market or restricted to avoid unexpected adverse outcomes. Drug-induced liver injury (DILI) is a serious issue for drug development. Among DILIs, idiosyncratic DILIs have been a serious problem in drug development and clinical uses. Idiosyncratic DILI is most often unrelated to pharmacological effects or the dosing amount of a drug. The number of drugs that cause idiosyncratic DILI continue to grow in part because no practical preclinical tests have emerged that can identify drug candidates with the potential for developing idiosyncratic DILIs. Nevertheless, the implications of drug metabolism-related factors and immune-related factors on idiosyncratic DILIs has not been fully clarified because this toxicity can not be reproduced in animals. Therefore, accumulated evidence for the mechanisms of the idiosyncratic toxicity has been limited to only in vitro studies. This review describes current knowledge of the effects of cytochrome P450 (CYP)-mediated metabolism and its detoxification abilities based on studies of idiosyncratic DILI animal models developed recently. This review also focused on antiepileptic drugs, phenytoin (diphenyl hydantoin, DPH) and carbamazepine (CBZ), which have rarely caused severe adverse reactions, such as fulminant hepatitis, and have been recognized as sources of idiosyncratic DILI. The studies of animal models of idiosyncratic DILIs have produced new knowledge of chronic administration, CYP inductions/inhibitions, glutathione contents, and immune-related factors for the initiation of idiosyncratic DILIs. Considering changes in the drug metabolic profile and detoxification abilities, idiosyncratic DILIs caused by antiepileptic drugs will lead to understanding the mechanisms of these DILIs.

All guns blazing: management and survival of massive valproic acid overdose - case report and literature review

A 51-year-old woman, who intentionally ingested a massive dose of ~60 g of valproic acid which she was using as a mood stabilizer for bipolar affective disorder, presented within 30 minutes of ingestion to the emergency department. The patient was asymptomatic and was immediately started on decontamination therapy with activated charcoal (AC). Drug serum levels, liver functions, and ammonia levels were tested and followed up during treatment. Due to the massive ingestion and continuous rise in serum drug levels, the patient received regular multiple doses of AC, as well as l-carnitine for liver protection. The patient was started on extracorporeal therapy in the form of renal replacement therapy in the intensive care unit (ICU), followed by intermittent hemodialysis. Drug serum levels dropped significantly. Ammonia levels showed improvement with treatment. The patient was discharged from the ICU after 14 days of treatment. She was stable and in good condition with no residual hepatic or central nervous system (CNS) manifestations.

Antiepileptic Drugs and Liver Disease

Acute, symptomatic seizures or epilepsy may complicate the course of hepatic disease. Choosing the most appropriate antiepileptic drug in this setting represents a difficult challenge, as most medications are metabolized by the liver. This article focuses on the acute and chronic treatment of seizures in patients with advanced liver disease and reviews the hepatotoxic potential of specific antiepileptic drugs. Newer antiepileptic drugs without, or with minimal, hepatic metabolism, such as levetiracetam, lacosamide, topiramate, gabapentin, and pregabalin should be used as first-line therapy. Medications undergoing extensive hepatic metabolism, such as valproic acid, phenytoin, and felbamate should be used as drugs of last resort. In special circumstances, as in patients affected by acute intermittent porphyria, exposure to most antiepileptic drugs could precipitate attacks. In this clinical scenario, bromides, levetiracetam, gabapentin, and vigabatrin constitute safe choices. For the treatment of status epilepticus, levetiracetam and lacosamide, available in intravenous preparations, are good second-line therapies after benzodiazepines fail to control seizures. Hepatotoxicity is also a rare and unexpected side effect of some antiepileptic drugs. Drugs such as valproic acid, phenytoin, and felbamate, have a well-recognized association with liver toxicity. Other antiepileptic drugs, including phenobarbital, benzodiazepines, ethosuximide, and the newer generations of antiepileptic drugs, have only rarely been linked to hepatotoxicity. Thus physicians should be mindful of the pharmacokinetic profile and the hepatotoxic potential of the different antiepileptic drugs available to treat patients affected by liver disease.

A Case of Carbamazepine-induced Severe Cholestatic Hepatitis: Case Report and Review of Literature

Carbamazepine (CBZ) is one of the widely prescribed drugs in the field of neuropsychiatry. We report a case of a 27-year-old female patient presenting with severe cholestatic hepatitis presenting after the initiation of CBZ. We establish the probability of drug-induced liver injury using Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method causality assessment scale, and the patient had high probability with a score of 9. We briefly review the literature in this field discussing the scope of the problem, etiopathogenesis, clinical manifestation, course, and management.

Maternal carbamazepine alters fetal neuroendocrine-cytokines axis

This study detected the impact of maternal carbamazepine (CBZ) on the fetal neuroendocrine-cytokines axis. 25 or 50mg/kg of CBZ was intraperitoneally administrated to pregnant albino rats from the gestation day (GD) 1 to 20. Both administrations of CBZ caused a hypothyroidism in dams and fetuses whereas the decreases in serum thyroxine (T4) and triiodothyronine (T3) and increases in serum thyrotropin (TSH) levels were highly significant (LSD; P <0.01) at GD 20 compared to untreated control dams. Also, both administrations had undesirable impacts on the maternofetal body weight, litter weight, survival of dams and fetuses, and their food consumption in comparison to the corresponding control. These administrations also elicited a reduction in fetal serum growth hormone (GH), interferon-γ (IFNγ), interleukins (IL-2 & 4) and prostaglandin E2 (PGE2) levels. Also, the elevation in fetal serum tumor necrosis factor-alpha (TNFα), transforming growth factor-beta (TGFβ), and interleukins (IL-1β & 17) levels was observed at embryonic day (ED) 20. Moreover, there were a cellular fragmentation, distortion, hyperemia, oedema and vacuolation in the fetal cerebellar cortex due to both maternal administrations. These developmental changes were dose-dependent. These novel results suggest that CBZ may act as a developmental immunoneuroendocrine disruptor.

Association between antiepileptic drugs and hepatocellular carcinoma in patients with epilepsy: a population-based case-control study

BACKGROUND

This study explored whether antiepileptic drugs (AEDs) use increases the risk of hepatocellular carcinoma (HCC).

METHODS

We conducted a case-control study using data from the National Health Insurance system of Taiwan. The case group comprised 1,454 epilepsy patients with newly diagnosed HCC, and the control group comprised 1,448 epilepsy patients without HCC. Both groups had similar distributions of sex and age, and follow-up duration. Possible associations with the AEDs in Taiwan were examined.

RESULTS

After adjusted for AEDs (phenobarbital and primidone, clonazepam, clorazepate and diazepam, and other AEDs), and for the comorbidities of diabetes, chronic liver disease and cirrhosis, hepatitis B and C virus infection, and alcoholism, the odds ratio (OR) of HCC was 1.22 (95% confidence interval [CI]: 1.01-1.47) for the group of phenytoin users compared with nonphenytoin users. An annual means of 61-120, 121-180, and >180 of defined daily doses (DDDs) of phenytoin (OR: 4.07, 95% CI: 2.03-8.18; OR: 7.51, 95% CI: 3.03-18.7, and OR: 14.6, 95% CI: 7.88-26.9, respectively) were significantly correlated with the risk of HCC but not with a DDD of ≤60. Compared with nonphenytoin users, HCC patients who had used phenytoin within 1 year of HCC diagnosis were at a greatest risk of HCC (adjusted OR: 2.29, 95% CI: 1.71-3.08), followed by who had used phenytoin within 2 years of diagnosis (adjusted OR: 1.92, 95% CI: 1.44-2.56).

CONCLUSION

The results indicate that high dose of phenytoin was associated with a statistically significant increased OR for HCC, which was not demonstrated for low-dose phenytoin.

The pathogenesis of drug-induced liver injury

Drugs can induce liver injury when taken as an over-dose, or even at therapeutic doses in susceptible individuals. Although severe drug-induced liver injury (DILI) is a relatively uncommon clinical event, it is a potentially life threatening adverse drug reaction and is the most common indication for the drug withdrawal. Areas covered: However, the diagnosis of DILI remains a significant challenge, because the establishment of causality is very difficult, and the histopathologic findings of DILI may be indistinguishable from those of other hepatic disorders, such as viral and alcoholic hepatitis. In this review, we provide an overview of recent advances in identification of serologic markers of diagnosis and prognosis, etiologic factors for susceptibility and diagnostic evaluation of DILI, with a focus on its pathogenic mechanisms and the role of liver biopsy. Expert commentary: Further studies of divergent research platforms, using a systems biology approach such as genomics and transcriptomics, may provide a deeper understanding of human drug metabolism and the causes, risk factors, and pathogenesis of DILI.

Ferulic acid exhibits antiepileptogenic effect and prevents oxidative stress and cognitive impairment in the kindling model of epilepsy

AIMS

Some conventional antiepileptic drugs induce oxidative stress and cognitive impairment which may limit their clinical applications. Ferulic acid is a phenolic phytochemical with antioxidant and neuroprotective properties that prompted us to evaluate its therapeutic potential in epilepsy which is usually associated with oxidative stress and cognitive decline.

MATERIALS AND METHODS

Male Wistar rats received 30mg/kg of pentylenetetrazole (PTZ) intraperitoneally (i.p.) once every alternate day until the development of kindling. The locomotor activity, elevated plus maze, and passive avoidance tests were performed. Oxidative stress was evaluated by the determination of brain malondialdehyde and reduced glutathione. The effects of pre-treatment with ferulic acid (25, 50, 75, and 100mg/kg, i.p.) against PTZ-kindled seizures, cognitive impairment, and oxidative stress were investigated.

KEY FINDINGS

Kindling was developed 34.18±1.54days after PTZ treatment which was associated with generalized tonic-clonic seizures (GTCS), myoclonic jerks, cognitive deficit, and oxidative stress. Ferulic acid at doses of 75 and 100mg/kg significantly reduced the seizure score, number of myoclonic jerks, cognitive decline and oxidative stress. Spontaneous locomotor activity did not significantly differ between the groups.

SIGNIFICANCE

Ferulic acid exhibits antiepileptogenic effect and prevents oxidative stress and cognitive impairment induced by PTZ kindling. Therefore, this phenolic phytochemical appears as a promising adjuvant for antiepileptic drugs. Meanwhile, further experimental and clinical studies are required to provide insights into the cellular/molecular mechanism(s) underlying the action of ferulic acid.

Oxcarbazepine-induced liver injury after sensitization by valproic acid: a case report

OBJECTIVE

The aim of the present case report is to describe a potential interaction between valproic acid and oxcarbazepine that resulted in hepatic injury.

METHODS

We report the case of a 46-year-old man with schizoaffective disorder who was cross-titrated from valproic acid to oxcarbazepine because of liver injury.

RESULTS

Initiation of oxcarbazepine four days after stopping valproic acid produced a significant elevation in liver enzymes that normalized with oxcarbazepine discontinuation and did not reappear with its reintroduction five days later.

CONCLUSIONS

Our findings suggest that a longer washout period or another agent should be considered when transitioning from valproic acid to oxcarbazepine.

Hepatic Dysfunction as a Complication of Combined Valproate and Ketogenic Diet

BACKGROUND

The ketogenic diet has long been shown to be an effective therapy for children with medication-refractory seizures. Most complications of the ketogenic diet include short-lived gastrointestinal disturbances, acidosis, and dyslipidemia. Hepatic dysfunction and pancreatitis are among the less common but more serious complications of the ketogenic diet. Many patients on the ketogenic diet receive adjunct treatment with an anticonvulsant drug, and valproate is frequently used.

METHODS AND RESULTS

We describe a child who developed hepatic dysfunction in association with the combined use of valproate and the ketogenic diet. After stopping the valproate and then restarting the ketogenic diet, her liver enzymes normalized, and she was able to achieve markedly improved seizure control and quality of life.

CONCLUSIONS

Although caution should be advised when using both treatments simultaneously, the development of hepatic dysfunction should not preclude continuation of the ketogenic diet, as the hepatotoxic effects may be completely reversed once the valproate is stopped.

A two-photon fluorescent sensor revealing drug-induced liver injury via tracking γ-glutamyltranspeptidase (GGT) level in vivo

Currently drug-induced liver injury (DILI) has become a major and challenging public health issue in terms of medicine development and clinical therapy. The level of γ-glutamyl transpeptidase (GGT) has long been regarded as a preclinical/clinical biomarker for prediction of DILI. Herein, we report a two-photon fluorescent sensor for tracking GGT level changes resulted from DILI in vivo. The sensor was prepared by linking a glutamic acid to a dicyanomethylene-4H-pyran (DCM) derivative; and the presence of GGT cleaves γ-glutamyl amide group from the sensor and thereby restores the fluorescence emission (at 635 nm) of DCM moiety under femtosecond pulses at 800 nm. This two-photon sensor exhibits superior sensing performance such as red emission, high photostability and low detection limit (∼0.057 U/L). On a two-photon microscope, the sensor shows a bright red fluorescence in GGT-overexpressing A2780 cells; and it can fluorescently respond to the GGT generated in the liver of zebrafishes as a result of clinical drug (phenytoin) treatment. These findings demonstrate that a commonly-used clinical drug phenytoin can cause remarkable elevation in GGT level in liver, and this sensor may be useful as a marker to detect clinical drug-induced organ damages.

Carbamazepine-Induced Liver Injury Requires CYP3A-Mediated Metabolism and Glutathione Depletion in Rats

Carbamazepine (CBZ) is widely used as an antiepileptic agent and causes rare but severe liver injury in humans. It has been generally recognized that reactive metabolites formed via the metabolic activation reaction contribute to the onset of liver injuries by several drugs. However, the role of CBZ metabolism in the development of liver injury is not fully understood. In this study, we developed a novel rat model of CBZ-induced liver injury and attempted to elucidate the associated mechanisms by focusing on the metabolism of CBZ. The repeated administration of CBZ for 5 days in combination with l-buthionine sulfoximine (BSO), a glutathione (GSH) synthesis inhibitor, resulted in increases in the plasma alanine aminotransferase (ALT) levels and centrilobular necrosis in the liver that were observed in various degrees. The CBZ and 2-hydroxy-CBZ concentrations in the plasma after the last CBZ administration were lower in the rats with high plasma ALT levels compared with those with normal plasma ALT levels, showing the possibility that the further metabolism of CBZ and/or 2-hydroxy-CBZ is associated with the liver injury. Although a single administration of CBZ did not affect the plasma ALT levels, even when cotreated with BSO, pretreatment with dexamethasone, a CYP3A inducer, increased the plasma ALT levels. In addition, the rats cotreated with troleandomycin or ketoconazole, CYP3A inhibitors, suppressed the increased plasma ALT levels. In conclusion, reactive metabolite(s) of CBZ produced by CYP3A under the GSH-depleted condition might be involved in the development of liver injury in rats.

Valproate-induced liver injury: modulation by the omega-3 fatty acid DHA proposes a novel anticonvulsant regimen

Background

The polyunsaturated, ω-3 fatty acid, docosahexaenoic acid (DHA), claims diverse cytoprotective potentials, although via largely undefined triggers. Thus, we currently first tested the ability of DHA to ameliorate valproate (VPA)-evoked hepatotoxicity, to modulate its anticonvulsant effects, then sought the cellular and molecular basis of such actions. Lastly, we also verified whether DHA may kinetically alter plasma levels/clearance rate of VPA.

Methods and Results

VPA (500 mg/kg orally for 14 days in rats) evoked prominent hepatotoxicity that appeared as a marked rise (2- to 4-fold) in serum hepatic enzymes (γ-glutamyl transferase [γ-GT], alanine aminotransferase [ALT], and alkaline phosphatase [ALP]), increased hepatic lipid peroxide (LPO) and tumor necrosis factor-alpha (TNFα) levels, as well as myeloperoxidase (MPO) activity (3- to 5-fold), lowering of serum albumin (40 %), and depletion of liver reduced-glutathione (GSH, 35 %). Likewise, histopathologic examination revealed hepatocellular degeneration, replacement by inflammatory cells, focal pericentral necrosis, and micro/macrovesicular steatosis. Concurrent treatment with DHA (250 mg/kg) markedly blunted the elevated levels of liver enzymes, lipid peroxides, TNFα, and MPO activity, while raising serum albumin and hepatic GSH levels. DHA also alleviated most of the cytologic insults linked to VPA. Besides, in a pentylenetetrazole (PTZ) mouse convulsion model, DHA (250 mg/kg) markedly increased the latency in convulsion evoked by VPA, beyond their individual responses. Lastly, pharmacokinetic studies revealed that joint DHA administration did not alter serum VPA concentrations.

Conclusions

DHA substantially ameliorated liver injury induced by VPA, while also markedly boosted its pharmacologic effects. DHA manipulated definite cellular machinery to curb liver oxidative stress and inflammation, without affecting VPA plasma levels. Collectively, these protective and synergy profiles for DHA propose a superior VPA-drug combination regimen.