Antiseizure medications for idiopathic generalized epilepsies: a systematic review and network meta-analysis.

OBJECTIVES: To compare the efficacy and safety of antiseizure medications (ASMs), both as monotherapies and adjunctive therapies, for idiopathic generalized epilepsies (IGEs) and related entities. METHODS: Two reviewers independently searched PubMed, Embase, and the Cochrane Library for relevant randomized controlled trials from December 2022 to February 2023. Studies on the efficacy and safety of ASM monotherapies or adjunctive therapies for IGEs and related entities-including juvenile myoclonic epilepsy, childhood absence epilepsy (CAE), juvenile absence epilepsy, or generalized tonic-clonic seizures alone (GTCA)-were included. Efficacy outcomes were the proportions of patients remaining seizure free for 1, 3, 6, and 12 months; safety outcomes were the proportions of any treatment-emergent adverse event (TEAE) and TEAEs leading to discontinuation. Network meta-analyses were performed in a random-effects model to obtain odds ratios and 95% confidence intervals. Rankings of ASMs were based on the surface under the cumulative ranking curve (SUCRA). This study is registered with PROSPERO (No. CRD42022372358). RESULTS: Twenty-eight randomized controlled trials containing 4282 patients were included. As monotherapies, all ASMs were more effective than placebo, and valproate and ethosuximide were significantly better than lamotrigine. According to the SUCRA for efficacy, ethosuximide ranked first for CAE, whereas valproate ranked first for other types of IGEs. As adjunctive therapies, topiramate ranked best for GTCA as well as overall for IGEs, while levetiracetam ranked best for myoclonic seizures. For safety, perampanel ranked best (measured by any TEAE). CONCLUSIONS: All of the studied ASMs were more effective than placebo. Valproate monotherapy ranked best overall for IGEs, whereas ethosuximide ranked best for CAE. Adjunctive topiramate and levetiracetam were most effective for GTCA and myoclonic seizures, respectively. Furthermore, perampanel had the best tolerability.

Model-Informed Precision Dosing Guidance of Ethosuximide Developed from a Randomized Controlled Clinical Trial of Childhood Absence Epilepsy.

Ethosuximide was identified as the optimal option for new-onset childhood absence epilepsy (CAE) in a randomized, two-phase dose escalation comparative effectiveness trial of ethosuximide, lamotrigine, and valproic acid. However, 47% of ethosuximide initial monotherapy participants experienced short-term treatment failure. This study aimed to characterize the initial monotherapy ethosuximide exposure-response relationship and to propose model-informed precision dosing guidance. Dose titration occurred over a 16-20-week period until patients experienced seizure freedom or intolerable side effects. Subjects with initial monotherapy failure were randomized to one of the other two medications and dose escalation was repeated. A population pharmacokinetic model was created using plasma concentration data (n = 1,320), collected at 4-week intervals from 211 unique participants during both the initial and second monotherapy phases. A logistic regression analysis was performed on the initial monotherapy cohort (n = 103) with complete exposure-response data. Eighty-four participants achieved seizure freedom with a wide range of ethosuximide area under the curves (AUC) ranging from 420 to 2,420 µg·h/mL. AUC exposure estimates for achieving a 50% and 75% probability of seizure freedom were 1,027 and 1,489 µg·h/mL, respectively, whereas the corresponding cumulative frequency of intolerable adverse events was 11% and 16%. Monte Carlo Simulation indicated a daily dose of 40 and 55 mg/kg to achieve 50% and 75% probability of seizure freedom in the overall population, respectively. We identified the need for adjusted mg/kg dosing in different body weight cohorts. This ethosuximide proposed model-informed precision dosing guidance to achieve seizure freedom carries promise to optimize initial monotherapy success for patients with CAE.

Severe Raynaud's phenomenon from ethosuximide raised concern over possible onset of systemic vasculitis: a case report.

BACKGROUND: Ethosuximide and other anti-epileptic drugs have been reported to cause idiosyncratic reactions such as lupus-like syndromes, with elevated antinuclear antibody (ANA) levels. Herein, we present a case of a girl who developed a very severe Raynaud's phenomenon reaction and anti-Scl-70 antibodies related to treatment with ethosuximide, due to juvenile absence epilepsy (JAE). CASE PRESENTATION: A 12-year-old girl was diagnosed with JAE and treatment with ethosuximide was initiated. Two and a half months later her fingers, digits II-V bilaterally, began to ache and were discolored, alternatingly white, blue, or normal-colored. Two weeks later, her fingers were bluish-black, aching severely, almost continuously. The family sought medical advice. Ethosuximide was halted and due to the severe symptoms, treatment with both prednisolone and intravenous iloprost was commenced. Laboratory tests revealed high ANA levels with anti-Scl-70 pattern and confirmed anti-Scl-70 antibodies. After a few weeks, she started to improve and the symptoms slowly decreased over five months. Anti-Scl-70 was still detectable four months after onset of symptoms, though she was much improved. After eleven months, repeated ANA analyses were completely negative. CONCLUSION: Although extremely rare, it is important to recognize that severe Raynaud's phenomenon, threatening peripheral digital circulation, may occur as an idiosyncratic reaction to ethosuximide, raising concern over possible onset of vasculitis.

Effects of antiseizure monotherapy on visuospatial memory in pediatric age.

INTRODUCTION: Visuospatial abilities are fundamental for good school achievements and good daily functioning. Previous studies showed an impairment of visuospatial skills in pediatric patients with epilepsy; pharmacological treatment, although indispensable for the seizure control, could further affect cognitive functions. The aim of our study was to evaluate the visuospatial skills in children and adolescents with different forms of epilepsy well-controlled by antiseizure monotherapy, both at baseline and after one year follow-up, through a standardized neuropsychological assessment. METHODS: We recruited 207 children and adolescents (mean age = 10.35 ± 2.39 years) with epilepsy, well controlled by monotherapy with levetiracetam, valproic acid, ethosuximide, oxcarbazepine or carbamazepine and 45 age/sex-matched controls. All the participants performed the Rey-Osterrieth Complex Figure, a standardized test for visuospatial perception and visuospatial memory assessment, at baseline and after 12 month of drug therapy. Age, sex, executive functions, non-verbal intelligence, age at onset of epilepsy, epilepsy duration, epilepsy type, lobe and side of seizure onset were considered in our analysis. EEG, seizure frequency, and drug dose were also recorded. RESULTS: At baseline, the epilepsy group performed significantly worse than controls in the Immediate Recall test but not the Direct Copy test, without differences between epilepsy subgroups. Immediate Recall scores were related to age of seizure onset and epilepsy duration and executive functions. The re-assessment after 1 year showed that the Immediate Recall mean scores were not significantly changed in the levetiracetam and oxcarbazepine group, while they significantly worsened in the valproic acid, ethosuximide and carbamazepine groups. The Immediate Recall scores were correlated to age, age at onset of epilepsy, epilepsy duration, and executive functions. CONCLUSIONS: Children with epilepsy may exhibit visuospatial memory impairment compared to their peer, that may be correlated to some features of the epilepsy itself and to the impairment of executive functions. Different antiseizure medications can affect visuospatial memory differently, so it is important monitoring this aspect in pediatric patients.

Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents.

BACKGROUND: This is an updated version of the Cochrane Review previously published in 2019. Absence seizures (AS) are brief epileptic seizures which present in childhood and adolescence. Depending on clinical features and electroencephalogram (EEG) findings they are divided into typical, atypical absences, and absences with special features. Typical absences are characterised by sudden loss of awareness and an EEG typically shows generalised spike wave discharges at three cycles per second. Ethosuximide, valproate and lamotrigine are currently used to treat absence seizures. This review aims to determine the best choice of antiepileptic drug for children and adolescents with AS. OBJECTIVES: To review the evidence for the effects of ethosuximide, valproate and lamotrigine as treatments for children and adolescents with absence seizures (AS), when compared with placebo or each other. SEARCH METHODS: For the latest update we searched the Cochrane Register of Studies (CRS Web, 22 September 2020) and MEDLINE (Ovid, 1946 to September 21, 2020). CRS Web includes randomised or quasi-randomised, 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 Epilepsy. No language restrictions were imposed. In addition, we contacted Sanofi Winthrop, Glaxo Wellcome (now GlaxoSmithKline) and Parke Davis (now Pfizer), manufacturers of sodium valproate, lamotrigine and ethosuximide respectively. SELECTION CRITERIA: Randomised parallel group monotherapy or add-on trials which include a comparison of any of the following in children or adolescents with AS: ethosuximide, sodium valproate, lamotrigine, or placebo. DATA COLLECTION AND ANALYSIS: Outcome measures were: 1. proportion of individuals seizure free at one, three, six, 12 and 18 months post randomisation; 2. individuals with a 50% or greater reduction in seizure frequency; 3. normalisation of EEG and/or negative hyperventilation test; and 4. adverse effects. Data were independently extracted by two review authors. Results are presented as risk ratios (RR) with 95% confidence intervals (95% CIs). We used GRADE quality assessment criteria to evaluate the certainty of evidence for the outcomes derived from all included studies. MAIN RESULTS: On the basis of our selection criteria, we included no new studies in the present review. Eight small trials (total number of participants: 691) were included from the earlier review. Six of them were of poor methodological quality (unclear or high risk of bias) and seven recruited less than 50 participants. There are no placebo-controlled trials for ethosuximide or valproate, and hence, no evidence from randomised controlled trials (RCTs) to support a specific effect on AS for either of these two drugs. Due to the differing methodologies used in the trials comparing ethosuximide, lamotrigine and valproate, we thought it inappropriate to undertake a meta-analysis. One large randomised, parallel double-blind controlled trial comparing ethosuximide, lamotrigine and sodium valproate in 453 children with newly diagnosed childhood absence epilepsy found that at 12 months, seizure freedom was higher in patients taking ethosuximide (70/154, 45%) than in patients taking lamotrigine (31/146, 21%; P < 0.001), with no difference between valproate (64/146, 44%) and ethosuximide (70/154, 45%; P > 0.05). In this study, the frequency of treatment failures due to intolerable adverse events was significantly different among the treatment groups, with the largest proportion of adverse events in the valproic acid group (48/146, 33%) compared to the ethosuximide (38/154, 25%) and the lamotrigine (29/146, 20%) groups (P < 0.037). Overall, this large study demonstrates the superior effectiveness of ethosuximide and valproic acid compared to lamotrigine as initial monotherapy aimed to control seizures without intolerable adverse effects in children with childhood absence epilepsy. This study provided high certainty of the evidence for outcomes for which data were available. However, the certainty of the evidence provided by the other included studies was low, primarily due to risk of bias and imprecise results because of the small sample sizes. Hence, conclusions regarding the efficacy of ethosuximide, valproic acid and lamotrigine derive mostly from this single study. AUTHORS' CONCLUSIONS: Since the last version of this review was published, we have found no new studies. Hence, the conclusions remain the same as the previous update. With regards to both efficacy and tolerability, ethosuximide represents the optimal initial empirical monotherapy for children and adolescents with AS. However, if absence and generalised tonic-clonic seizures coexist, valproate should be preferred, as ethosuximide is probably inefficacious on tonic-clonic seizures.

Efficacy of anticonvulsant ethosuximide for major depressive disorder: a randomized, placebo-control clinical trial.

Results of a preclinical study suggested that the anticonvulsant drug ethosuximide may elicit ketamine-like rapid-acting antidepressant actions. We evaluated the antidepressant efficacy of ethosuximide versus placebo in non-medicated adult patients with major depressive disorder (MDD). This randomized, double-blind, placebo-controlled trial included patients at three mental health centers in China. Eighty eligible adults (aged 18-65 years) met the DSM-5 criteria for MDD. Patients in the acute single study received three doses (500, 1000, or 1500 mg) of ethosuximide or placebo. Patients in the repeated study received ethosuximide (1500 mg/day) or placebo for 2 weeks. The Hamilton Depression Rating Scale (HAM-D), the Montgomery-Åsberg Depression Rating Scale (MADRS), and the Hamilton Anxiety Rating Scale were used to assess antidepressant and antianxiety responses to ethosuximide. No significant reductions in depression and anxiety rating scale scores were observed after a single oral administration of ethosuximide, in comparison with placebo. Furthermore, patients receiving ethosuximide for 2 weeks did not show reductions in depression and anxiety rating scale scores. There were no serious adverse events. Responses to the study's primary and secondary outcome measures, the clinician-rated HAM-D and MADRS, showed no change from baseline to the end of treatment, with either ethosuximide or placebo. These results suggest that ethosuximide does not produce ketamine-like robust antidepressant actions in adult patients with MDD.

Identification of significant protein markers by mass spectrometry after co-treatment of cells with different drugs: An in vitro survey platform.

RATIONALE: Understanding drug-drug interactions and predicting the side effects induced by polypharmacy are difficult because there are few suitable platforms that can predict drug-drug interactions and possible side effects. Hence, developing a platform to identify significant protein markers of drug-drug interactions and their associated side effects is necessary to avoid adverse effects. METHODS: Human liver cells were treated with ethosuximide in combination with cimetidine, ketotifen, metformin, metronidazole, or phenytoin. After sample preparation and extraction, mitochondrial proteins from liver cells were isolated and digested with trypsin. Then, peptide solutions were detected using a nano ultra-performance liquid chromatographic system combined with tandem mass spectrometry. The Ingenuity Pathway Analysis tool was used to simulate drug-drug interactions and identify protein markers associated with drug-induced adverse effects. RESULTS: Several protein markers were identified by the proposed method after liver cells were co-treated with ethosuximide and other drugs. Several of these protein markers have previously been reported in the literature, indicating that the proposed platform is workable. CONCLUSIONS: Using the proposed in vitro platform, significant protein markers of drug-drug interactions could be identified by mass spectrometry. This workflow can then help predict indicators of drug-drug interactions and associated adverse effects for increased safety in clinical prescriptions.

Ethosuximide-induced drug reaction with eosinophilia and systemic symptoms with mediastinal lymphadenopathy.

Lymphadenopathy is a common sign for drug reaction and eosinophilia with systemic symptoms (DRESS) syndrome, but hilar and mediastinal lymphadenopathy may be underreported. We describe a 7-year-old boy who started taking ethosuximide for absence seizures and presented with diffuse rash, fever, elevated transaminases, facial swelling, and hilar and mediastinal lymphadenopathy. His mediastinal lymphadenopathy was concerning for lymphoma, which led to more invasive testing to rule out malignancy. This report highlights an unusual and likely underreported presenting sign of DRESS syndrome in children.

Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents.

BACKGROUND: This is an updated version of the Cochrane Review previously published in 2017.Absence seizures (AS) are brief epileptic seizures which present in childhood and adolescence. Depending on clinical features and electroencephalogram (EEG) findings they are divided into typical, atypical absences, and absences with special features. Typical absences are characterised by sudden loss of awareness and an EEG typically shows generalised spike wave discharges at three cycles per second. Ethosuximide, valproate and lamotrigine are currently used to treat absence seizures. This review aims to determine the best choice of antiepileptic drug for children and adolescents with AS. OBJECTIVES: To review the evidence for the effects of ethosuximide, valproate and lamotrigine as treatments for children and adolescents with absence seizures (AS), when compared with placebo or each other. SEARCH METHODS: For the latest update we searched the Cochrane Register of Studies (CRS Web, 29 May 2018), which includes the Cochrane Epilepsy Group's Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid, 1946 to 29 May 2018), ClinicalTrials.gov (29 May 2018) and the WHO International Clinical Trials Registry Platform (ICTRP, 29 May 2018). Previously we searched Embase (1988 to March 2005) and SCOPUS (1823 to 31 March 2014), but this is no longer necessary because randomised controlled trials (RCTs) and quasi-RCTs in Embase and SCOPUS are now included in CENTRAL. No language restrictions were imposed. In addition, we contacted Sanofi Winthrop, Glaxo Wellcome (now GlaxoSmithKline) and Parke Davis (now Pfizer), manufacturers of sodium valproate, lamotrigine and ethosuximide respectively. SELECTION CRITERIA: Randomised parallel group monotherapy or add-on trials which include a comparison of any of the following in children or adolescents with AS: ethosuximide, sodium valproate, lamotrigine, or placebo. DATA COLLECTION AND ANALYSIS: Outcome measures were: (1) proportion of individuals seizure free at one, three, six, 12 and 18 months post randomisation; (2) people with a 50% or greater reduction in seizure frequency; (3) normalisation of EEG and/or negative hyperventilation test; and (4) adverse effects. Data were independently extracted by two review authors. Results are presented as risk ratios (RR) with 95% confidence intervals (95% CIs). We used GRADE quality assessment criteria to evaluate the certainty of evidence derived from all included studies. MAIN RESULTS: On the basis of our selection criteria, we included no new studies in the present review. Eight small trials (total number of participants: 691) were included from the earlier review. Six of them were of poor methodological quality (unclear or high risk of bias) and seven recruited less than 50 participants. There are no placebo-controlled trials for ethosuximide or valproate, and hence, no evidence from RCTs to support a specific effect on AS for either of these two drugs. Due to the differing methodologies used in the trials comparing ethosuximide, lamotrigine and valproate, we thought it inappropriate to undertake a meta-analysis. One large randomised, parallel double-blind controlled trial comparing ethosuximide, lamotrigine and sodium valproate in 453 children with newly diagnosed childhood absence epilepsy found that at 12 months, the freedom-from-failure rates for ethosuximide and valproic acid were similar and were higher than the rate for lamotrigine. The frequency of treatment failures due to lack of seizure control (P < 0.001) and intolerable adverse events (P < 0.037) was significantly different among the treatment groups, with the largest proportion of lack of seizure control in the lamotrigine cohort, and the largest proportion of adverse events in the valproic acid group. Overall, this large study demonstrates the superior effectiveness of ethosuximide and valproic acid compared to lamotrigine as initial monotherapy aimed to control seizures without intolerable adverse effects in children with childhood absence epilepsy. The risk of bias for this study was low. We rated the overall certainty of the evidence available from the included studies to be moderate or high. AUTHORS' CONCLUSIONS: Since the last version of this review was published, we have found no new studies. Hence, the conclusions remain the same as the previous update. With regards to both efficacy and tolerability, ethosuximide represents the optimal initial empirical monotherapy for children and adolescents with AS. However, if absence and generalised tonic-clonic seizures coexist, valproate should be preferred, as ethosuximide is probably inefficacious on tonic-clonic seizures.

[Medicaments and oral healthcare. Proliferation of the gingiva]. / Serie: Medicamenten en mondzorg. Proliferatie van de gingiva.

Adverse effects of medications and self care products on the gingiva can be divided into inflammation, intrinsic discolouration, irritation, trauma, cytotoxicity, lichenoid reaction, and proliferation. This article deals with the last-mentioned type of adverse effects; the other 6 have been discussed in a previous article. Proliferation of the gingiva as an adverse effect of medications has been reported for anticonvulsants, calcineurin inhibitors, calcium channel blockers and isotretinoin. With regard to the anticonvulsants that have been registered in the Netherlands, proliferation of the gingiva is predominantly induced by phenytoin, but also by carbamazepine, ethosuximide, phenobarbital, gabapentin, levetiracetam, primidone and valproic acid. All calcineurin inhibitors registered in the Netherlands may induce the adverse effect. This is also the case for nearly all calcium channel blockers, but particularly for dihydropyridines. Presumably, proliferation of the gingiva may be prevented or reduced in a number of ways. The most important one is good oral hygiene. Furthermore, proteins and cells that play an important role [in the process of gingival proliferation] have been discovered and there are medications that have the potential to eliminate these proteins and cells.

Ethosuximide-induced Stevens-Johnson syndrome: Beneficial effect of early intervention with high-dose corticosteroid therapy.

We report two rare cases of childhood epilepsy patients who developed ethosuximide-induced Stevens-Johnson syndrome (SJS). Unlike typical SJS, the initial eruption of both patients presented well-demarcated, infiltrating firm papules mainly on the cheeks and the extensor aspects of the arms (case 1), and multiple vesicles on the soles and oral aphthosis (case 2), which closely mimicked viral exanthema. We diagnosed both patients with ethosuximide-induced SJS, based on the dosing period and the positive results of drug-induced lymphocyte stimulation test. Systemic corticosteroids are usually selected as a standard therapy for SJS, despite controversial results regarding their effectiveness. In case 1, an i.v. pulse therapy of methylprednisolone (30 mg/kg, 3 days consecutively) was initiated on day 7 from the onset of illness, and an i.v. immunoglobulin (400 mg/kg, 5 days consecutively) was added the following day. In case 2, an i.v. prednisone treatment (1 mg/kg, for 1 week) was initiated on day 4 from the onset. Eventually, the early therapeutic interventions resulted in good outcomes in both patients.

Development of forced normalisation psychosis with ethosuximide.

A 50-year-old man with known multidrug resistant coexistent focal and generalised epilepsy was commenced on ethosuximide, with normalisation of his electroencephalogram and cessation of absence seizures. Within 3 weeks, he developed a rapidly worsening paranoid psychosis with visual and olfactory hallucinations. A month after the cessation of ethosuximide and concurrent treatment with olanzapine, his psychosis resolved and permitted reinitiation of ethosuximide at a lower dose without recurrence of psychotic symptoms.

Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents.

BACKGROUND: This is an updated version of the original Cochrane review originally published in 2003, Issue 3, and updated in 2005, Issue 4.Absence seizures are brief epileptic seizures which present in childhood and adolescence. Depending on clinical features and electroencephalogram (EEG) findings they are divided into typical, atypical absences, and absences with special features. Typical absences are characterised by sudden loss of awareness and an EEG typically shows generalised spike wave discharges at three cycles per second. Ethosuximide, valproate and lamotrigine are currently used to treat absence seizures. This review aims to determine the best choice of antiepileptic drug for children and adolescents with typical absence seizures. OBJECTIVES: To review the evidence for the effects of ethosuximide, valproate and lamotrigine as treatments for children and adolescents with absence seizures, when compared with placebo or each other. SEARCH METHODS: We searched the Cochrane Epilepsy Group's Specialized Register (1 September 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO, 1 September 2016), MEDLINE (Ovid, 1946 to 1 September 2016), ClinicalTrials.gov (1 September 2016) and the WHO International Clinical Trials Registry Platform ICTRP (1 September 2016). Previously we searched Embase (1988 to March 2005) and SCOPUS (1823 to 31 March 2014). No language restrictions were imposed. In addition, we contacted Sanofi Winthrop, Glaxo Wellcome (now GlaxoSmithKline) and Parke Davis (now Pfizer), manufacturers of sodium valproate, lamotrigine and ethosuximide respectively. SELECTION CRITERIA: Randomised parallel group monotherapy or add-on trials which include a comparison of any of the following in children or adolescents with absence seizures: ethosuximide; sodium valproate; lamotrigine; or placebo. DATA COLLECTION AND ANALYSIS: Outcome measures were: (1) proportion of individuals seizure free at one, three, six, 12 and 18 months post randomisation; (2) people with a 50% or greater reduction in seizure frequency; (3) normalisation of EEG and/or negative hyperventilation test; and (4) adverse effects. Data were independently extracted by two review authors. Results are presented as risk ratios (RR) with 95% confidence intervals (95% CIs). MAIN RESULTS: Eight small trials were found (three of them not included in the previous version of the review). Six of them were of poor methodological quality and seven recruited less than 50 participants. There are no placebo-controlled trials for ethosuximide or valproate, and hence, no evidence from randomised controlled trials to support a specific effect on absence seizures for either of these two drugs. Due to the differing methodologies used in the trials comparing ethosuximide, lamotrigine and valproate, we thought it inappropriate to undertake a meta-analysis. One large randomised, parallel double-blind controlled trial comparing ethosuximide, lamotrigine and sodium valproate in children with newly diagnosed childhood absence epilepsy found that at 12 months, the freedom-from-failure rates for ethosuximide and valproic acid (VPA) were similar and were higher than the rate for lamotrigine. The frequency of treatment failures due to lack of seizure control (P < 0.001) and intolerable adverse events (P < 0.037) was significantly different among the treatment groups, with the largest proportion of lack of seizure control in the lamotrigine cohort, and the largest proportion of adverse events in the VPA group. Overall, this large study demonstrates the superior effectiveness of ethosuximide and VPA compared to lamotrigine as initial monotherapy aimed to control seizures without intolerable adverse effects in children with childhood absence epilepsy. AUTHORS' CONCLUSIONS: With regards to both efficacy and tolerability, ethosuximide represents the optimal initial empirical monotherapy for children and adolescents with absence seizures. However, if absence and generalised tonic-clonic seizures coexist, valproate should be preferred, as ethosuximide is probably inefficacious on tonic-clonic seizures.

Effect of ethosuximide on cortisol metabolism in the treatment of congenital adrenal hyperplasia.

BACKGROUND: Antiepileptics may affect cortisol metabolism through CYP3A4. There is little known about ethosuximide. CLINICAL CASE: Our patient is a 12-year-old girl with salt-wasting congenital adrenal hyperplasia (CAH) owing to 21 hydroxylase deficiency. A standard treatment regimen was initiated with satisfactory results until the age of 6 years, when she developed absence seizures treated with ethosuximide. She received such therapy until the age of 12 years, at which point ethosuximide was discontinued. During ethosuximide administration, she experienced worsening control of CAH disease activity that responded to progressive increases in hydrocortisone dose up to 28 mg/m2 per day. Despite high doses of hydrocortisone, she suffered no cushingoid symptoms. Her requirements for high glucocorticoid replacement doses resolved shortly after ethosuximide was discontinued. We provide data over 6 years demonstrating a correlation between adrenal hormone secretion, cortisol requirements and ethosuximide dose. CONCLUSION: This is the first case demonstrating an interaction between ethosuximide and hydrocortisone clearance in the treatment of salt-wasting CAH.