Valproate-associated coagulopathies are frequent and variable in children

Coagulation abnormalities in children undergoing epilepsy surgery

OBJECT

Surgery is increasingly used to treat children with refractory epilepsy. Before surgery, the authors routinely evaluated the coagulation profile to identify coagulation abnormalities not established by personal and family history, physical examination, and routine screening tests.

METHODS

Thirty-nine consecutive children undergoing testing prior to epilepsy surgery were prospectively evaluated. The authors evaluated a detailed hematological history and an elaborative hematological panel including complete blood count, hepatic panel, anticoagulant levels, coagulation profile (prothrombin time, partial thromboplastin time, international normalized ratio, fibrinogen, thrombin time, von Willebrand antigen, ristocetin cofactor, factor VIII, and individual factor assays when indicated) and platelet aggregation studies (in the presence of adenosine diphosphate, epinephrine, collagen, and ristocetin). Patient variables included tuberous sclerosis complex (TSC), age at epilepsy onset, age at surgery, seizure frequency, number and type of antiepileptic drugs, recent or present ketogenic diet, and use of selective serotonin reuptake inhibitors.

RESULTS

Ten children (25.6%) had either coagulation or platelet function abnormalities. Abnormal coagulation was identified in 5 children, and abnormal platelet function was discovered in 6. A diagnosis of TSC was associated with a platelet function abnormality (p = 0.012), whereas children without TSC had a higher rate of coagulopathy (p = 0.041). None of the other characteristics reached statistical significance. In 2 patients (5.1%) with TSC and platelet aggregation abnormalities, the authors noted normal standard screening laboratory studies and an uneventful detailed personal and family history. One of these 2 patients developed a significant intraoperative bleeding complication.

CONCLUSIONS

A preoperative screening with standard laboratory studies and detailed history may not be adequate to fully examine underlying coagulation abnormalities in children with refractory epilepsy. Platelet aggregation studies should be considered in patients with TSC.

A preliminary investigation on the possible association between diminished copper availability and non-alcoholic fatty liver disease in epileptic patients treated with valproic acid

BACKGROUND

Patients treated with valproic acid (VPA) present a high incidence of non-alcoholic fatty liver disease (NAFLD) (around 61%). Several recent studies suggest that low copper stores could be associated with NAFLD, and a significant decrease of copper availability in VPA-treated patients has been described.

DESIGN AND METHODS

In 101 adult epileptic patients treated with valproic acid in monotherapy (n = 75) and polytherapy (n = 26) the copper availability was evaluated using the specific oxidase activity of ceruloplasmin (activity per unit mass of enzyme protein) and the copper/ceruloplasmin ratio. Copper deficiency was supposed in the cases in which this biochemical variable was smaller than the lower reference limit (333 U/g).

RESULTS

The differences between the groups of patients with ceruloplasmin oxidase activity smaller or greater than 333 U/g for the serum levels of aminotransferases, gamma-glutamyltransferase, butyrylcholinesterase, cholesterol, triglycerides, and C-reactive protein, and the APRI and FIB-4 liver fibrosis scores were not statistically significant. Most patients (93%) had low APRI and FIB-4 scores, suggesting absence of significant liver fibrosis.

CONCLUSIONS

The results obtained do not confirm the hypothesis of an association between diminished copper availability and NAFLD in patients treated with valproic acid.

Acyl glucuronides: the good, the bad and the ugly

Acyl glucuronidation is the major metabolic conjugation reaction of most carboxylic acid drugs in mammals. The physiological consequences of this biotransformation have been investigated incompletely but include effects on drug metabolism, protein binding, distribution and clearance that impact upon pharmacological and toxicological outcomes. In marked contrast, the exceptional but widely disparate chemical reactivity of acyl glucuronides has attracted far greater attention. Specifically, the complex transacylation and glycation reactions with proteins have provoked much inconclusive debate over the safety of drugs metabolised to acyl glucuronides. It has been hypothesised that these covalent modifications could initiate idiosyncratic adverse drug reactions. However, despite a large body of in vitro data on the reactions of acyl glucuronides with protein, evidence for adduct formation from acyl glucuronides in vivo is limited and potentially ambiguous. The causal connection of protein adduction to adverse drug reactions remains uncertain. This review has assessed the intrinsic reactivity, metabolic stability and pharmacokinetic properties of acyl glucuronides in the context of physiological, pharmacological and toxicological perspectives. Although numerous experiments have characterised the reactions of acyl glucuronides with proteins, these might be attenuated substantially in vivo by rapid clearance of the conjugates. Consequently, to delineate a relationship between acyl glucuronide formation and toxicological phenomena, detailed pharmacokinetic analysis of systemic exposure to the acyl glucuronide should be undertaken adjacent to determining protein adduct concentrations in vivo. Further investigation is required to ascertain whether acyl glucuronide clearance is sufficient to prevent covalent modification of endogenous proteins and consequentially a potential immunological response.

Valproate attenuates the risk of myocardial infarction in patients with epilepsy: a nationwide cohort study

PURPOSE

Patients with epilepsy have increased risk of myocardial infarction (MI). Valproate can exert anti-atherosclerotic effects. We therefore examined the risk of MI in patients with epilepsy receiving valproate.

METHODS

Two cohorts of patients with valproate-treated epilepsy and sex- and age-matched individuals (controls) from the general Danish population were identified by individual-level-linkage of nationwide registries and followed for 10 years. The two cohorts comprised patients treated with valproate at baseline and valproate-naïve patients initiating treatment in the study period, respectively. The hazard ratios (HR) of MI and all-cause death were estimated by two different Cox proportional-hazard models; valproate treatment was analysed as a baseline categorical covariate in the first cohort and as a time-dependent exposure covariate in the second cohort.

RESULTS

The two cohorts comprised 53,086 and 102,003 individuals, respectively. In the first cohort, the risk of MI was decreased (HR 0.75, 95% confidence interval 0.59-0.97) while the risk of all-cause death was increased (HR 2.11, 95% confidence interval 1.95-2.28), compared to the controls. In the second cohort, the risk of MI was decreased (HR 0.62, 95% confidence interval 0.53-0.73) while the risk of all-cause death was similar to the controls (HR 1.02, 95% confidence interval 0.97-1.07).

CONCLUSIONS

In this nationwide pharmacoepidemiological study, we found a consistent association between valproate treatment and a reduced risk of MI in patients with epilepsy.

Antiplatelet activity of valproic acid contributes to decreased soluble CD40 ligand production in HIV type 1-infected individuals

CD40L is a type II membrane glycoprotein of the TNF family that is found on activated T cells, B cells, and platelets. We previously reported that the soluble form of this inflammatory mediator (sCD40L) is elevated in the plasma and cerebrospinal fluid of HIV-1-infected, cognitively impaired individuals. In this study, we demonstrate that the mood-stabilizing drug valproic acid (VPA) reduces sCD40L levels in plasma samples of HIV-1-infected patients (n = 23) and in washed human platelets, which are the main source of circulating sCD40L. VPA also inhibited HIV-1 transactivator of transcription-induced release of sCD40L and platelet factor 4 in C57BL/6 mice. The mechanism by which VPA was able to do so was investigated, and we demonstrate that VPA, a known glycogen synthase kinase 3β inhibitor, blocks platelet activating factor-induced activation of glycogen synthase kinase 3β in platelets in a manner that alters sCD40L release from platelets. These data reveal that VPA has antiplatelet activity, and they convey important implications for the potential of VPA as an adjunct therapy not only for cognitively impaired patients with HIV-1 infection, but also numerous inflammatory diseases for which such antiplatelet therapies are currently lacking.

Molecular and therapeutic potential and toxicity of valproic acid

Valproic acid (VPA), a branched short-chain fatty acid, is widely used as an antiepileptic drug and a mood stabilizer. Antiepileptic properties have been attributed to inhibition of Gamma Amino Butyrate (GABA) transaminobutyrate and of ion channels. VPA was recently classified among the Histone Deacetylase Inhibitors, acting directly at the level of gene transcription by inhibiting histone deacetylation and making transcription sites more accessible. VPA is a widely used drug, particularly for children suffering from epilepsy. Due to the increasing number of clinical trials involving VPA, and interesting results obtained, this molecule will be implicated in an increasing number of therapies. However side effects of VPA are substantially described in the literature whereas they are poorly discussed in articles focusing on its therapeutic use. This paper aims to give an overview of the different clinical-trials involving VPA and its side effects encountered during treatment as well as its molecular properties.

The status of intravenous valproate for status

Sodium Valproate vs Phenytoin in Status Epilepticus: A Pilot Study. Misra UK, Kalita J, Patel R. Neurology 2006;67(2):340–342. Sixty-eight patients with convulsive status epilepticus (SE) were randomly assigned to two groups to study the efficacy of sodium valproate (VPA) and phenytoin (PHT). Seizures were aborted in 66% in the VPA group and 42% in the PHT group. As a second choice in refractory patients, VPA was effective in 79% and PHT was effective in 25%. The side effects in the two groups did not differ. Sodium valproate may be preferred in convulsive SE because of its higher efficacy.

Seizures in patients with low-grade gliomas--incidence, pathogenesis, surgical management, and pharmacotherapy

Seizures complicate the clinical course of > 80% of patients with low-grade gliomas. Patients with some tumor variants almost always have epilepsy. Diffuse low-grade gliomas (LGG) are believed to cause epilepsy through partial deafferentiation of nearby brain cortex (denervation hypersensitivity). Glioneural tumors may interfere with local neurotransmitter levels and are sometimes associated with structural abnormalities of the brain which may produce seizures. The severity of tumor associated epilepsy varies considerably between patients. Some cases may present with a first seizure. Others suffer from long-standing pharmacoresistant epilepsy. Seizure control rates of > 70-80% can be expected after complete tumor resections. Patients with drug-resistant epilepsy require a comprehensive preoperative epileptological work-up which may include the placement of subdural (and intraparenchymal) electrodes or intraoperative electrocorticography (ECoG) for the delineation of extratumoral seizure foci. Partial and subtotal tumor resections are helpful in selected cases, i.e. for gliomas involving the insula. In one series, 40% of patients presented for surgery with uncontrolled seizures, i.e. medical therapy alone often fails to control tumor-related epilepsy. Use of the newer (second generation) non-enzyme inducing antiepileptic drugs (non-EIAED) is encouraged since they seem to have lesser interactions with other medications (e.g. chemotherapy). Chemotherapy and irradiation may have some minor beneficial effects on the patients' seizure disorder. Overall 60-70% of patients may experience recurrent epilepsy during long-term follow-up. Recurrent seizures (not infrequently heralding tumor recurrence) after surgery continue to pose significant clinical problems.

Valproato de sódio: efeitos colaterais em crianças

OBJETIVO: O valproato de sódio é um fármaco anticonvulsivante usado com frequência no manejo dos quadros epilépticos refratários na infância e habitualmente apresenta boas taxas de resposta e toxicidade aceitável. O objetivo deste artigo é destacar os efeitos colaterais secundários ao uso prolongado de valproato de sódio em uma criança e alertar para a importância do acompanhamento dos pacientes em uso crônico de anticonvulsivantes. DESCRIÇÃO DO CASO: Criança do sexo masculino, com quatro anos e oito meses, portadora de síndrome de West, em uso de valproato de sódio desde os seis meses de idade, admitida no hospital com anemia, macrocitose, plaquetopenia, deficiência de vitamina B12, hipoalbuminemia e hiponatremia. Durante a internação e o acompanhamento ambulatorial, relacionou-se o quadro clínico ao uso do valproato de sódio. COMENTÁRIOS: A toxicidade hematológica do valproato de sódio é bem conhecida e comum, podendo variar em relação à época de instalação e gravidade. Os achados mais frequentes são a plaquetopenia e a macrocitose. Além das alterações hematológicas, a literatura relata outros efeitos colaterais relacionados ao uso do fármaco. Destaca-se a importância do conhecimento e monitorização dos eventos adversos nos pacientes submetidos a esse tipo de terapia, para que eles possam ser detectados e tratados o mais precocemente.

Valproate-associated coagulopathies in children during short-term treatment

Valproic acid is one of the most frequently prescribed antiepileptic drugs for the therapy of generalized and focal epilepsies. Valproate induces a variety of hemostatic disorders such as thrombocytopenia, abnormal platelet function, hypofibrinogenemia, and decreased concentrations of von Willebrand factor, and it rarely causes serious bleeding complications. It may also lead to atherosclerosis and thrombosis. However, there is still lack of knowledge about the incidence and occurrence of these particular side effects. In this prospective systematic study, we assessed the early effects of sodium valproate on both pro- and anticoagulatory factors, homocysteine, and lipoprotein (a) in 24 newly diagnosed epileptic children treated with valproate. Valproate causes decreased factor VII levels, platelet count, factor VIII, Protein C, fibrinogen, and increased lipoprotein (a) levels. To the best of our knowledge, our report is the first in the medical literature, which describes that valproate significantly reduces factor VII levels even during short-term therapy.

The International Society for Bipolar Disorders (ISBD) consensus guidelines for the safety monitoring of bipolar disorder treatments

OBJECTIVES

Safety monitoring is an important aspect of bipolar disorder treatment, as mood-stabilising medications have potentially serious side effects, some of which may also aggravate existing medical comorbidities. This paper sets out the International Society for Bipolar Disorders (ISBD) guidelines for the safety monitoring of widely used agents in the treatment of bipolar disorder. These guidelines aim to provide recommendations that take into consideration the balance between safety and cost-effectiveness, to highlight iatrogenic and preventive clinical issues, and to facilitate the broad implementation of therapeutic safety monitoring as a standard component of treatment for bipolar disorder.

METHODS

These guidelines were developed by an ISBD workgroup, headed by the senior author (MB), through an iterative process of serial consensus-based revisions. After this, feedback from a multidisciplinary group of health professionals on the applicability of these guidelines was sought to develop the final recommendations.

RESULTS

General safety monitoring recommendations for all bipolar disorder patients receiving treatment and specific monitoring recommendations for individual agents are outlined.

CONCLUSIONS

These guidelines are derived from evolving and often indirect data, with minimal empirical cost-effectiveness data available to provide guidance. These guidelines will therefore need to be modified to adapt to different clinical settings and health resources. Clinical acumen and vigilance remain critical ingredients for safe treatment practice.

Hemostatic and hemorrhagic problems in neurosurgical patients

BACKGROUND

Abnormalities of the hemostasis can lead to hemorrhage, and on the other hand to thrombosis. Intracranial neoplasms, complex surgical procedures, and head injury have a specific impact on coagulation and fibrinolysis. Moreover, the number of neurosurgical patients on medication (which interferes with platelet function and/or the coagulation systems) has increased over the past years.

METHOD

The objective of this review is to recall common hemostatic disorders in neurosurgical patients on the basis of the "new concept of hemostasis". Therefore the pertinent literature was searched to provide a structured and up to date manuscript about hemostasis in Neurosurgery.

FINDINGS

According to recent scientific publications abnormalities of the coagulation system are discussed. Pathophysiological background and the rational for specific (cost)-effective perioperative hemostatic therapy is provided.

CONCLUSIONS

Perturbations of hemostasis can be multifactorial and maybe encountered in the daily practice of neurosurgery. Early diagnosis and specific treatment is the prerequisite for successful treatment and good patients outcome.

A double-blind, randomized, placebo-controlled trial of divalproex extended-release in the treatment of bipolar disorder in children and adolescents

OBJECTIVE

To compare the efficacy and safety of divalproex extended-release (ER) to placebo in a 28-day double-blind study of bipolar disorder in children and adolescents and evaluate the safety of divalproex ER in a 6-month open-label extension study.

METHOD

In the double-blind study, 150 patients (manic or mixed episode, aged 10-17 years) with baseline Young Mania Rating Scale (YMRS) score of 20 or higher were randomized to once-daily placebo or divalproex ER, which was titrated to clinical response or serum valproate concentration of 80 to 125 microg/mL. Sixty-six patients enrolled in the extension study.

RESULTS

In the double-blind study, a treatment effect was not observed with divalproex ER based on change in mean YMRS score (divalproex ER -8.8 [n = 74]; placebo -7.9 [n = 70]) or secondary measures. Divalproex was similar to placebo based on incidence of adverse events. Four subjects treated with divalproex ER and three treated with placebo discontinued because of adverse events. Mean ammonia levels increased in the divalproex ER group, but only one patient was symptomatic. In the long-term study, YMRS scores decreased modestly (2.2 points from baseline). The most common adverse events were headache and vomiting.

CONCLUSIONS

The results of the study do not provide support for the use of divalproex ER in the treatment of youths with bipolar I disorder, mixed or manic state. Further controlled trials are required to confirm or refute the findings from this study.

Approach to pediatric epilepsy surgery: State of the art, Part I: General principles and presurgical workup

In 1990, the National Institute of Health adopted epilepsy surgery in children as an option when medications fail. In the past few years several concepts have become increasingly recognized as key to a successful approach to epilepsy surgery in children. These include the concepts of neuronal plasticity, the epileptogenic lesion, the ictal onset, symptomatogenic, irritative, and epileptogenic zones. In addition, several techniques have increasingly been utilized to delineate the above areas in an attempt to determine, in each patient, the epileptogenic zone, defined as the zone the resection of which leads to seizure freedom. When seizure semiology (which defines the symptomatogenic zone), ictal EEG (which identifies the ictal onset zone), and structural imaging (which identifies the epileptogenic lesion) can be reconciled to infer the location of the epileptogenic zone, surgery is usually, subsequently, undertaken. When these diagnostic modalities are discordant, not definitive, or when the epileptogenic zone is close to eloquent cortex, invasive EEG, complemented by other imaging techniques may be needed. These include magnetoencephalography, single photon emission tomography, various types of positron emission tomography, various magnetic resonance imaging modalities (functional, diffusion weighted, other) and other emerging and experimental techniques. While MRI, video-EEG, and neuropsychological assessments are well established components of the presurgical evaluation, the use of the new emerging imaging technologies is dictated by the degree of anatomo-electro-clinical correlations, and, awaiting multicentric studies and more detailed guidelines, remains center-dependent.

Valproate-associated reversible encephalopathy in a 3-year-old girl with Pallister-Killian syndrome

Valproic acid (VPA) is considered to be a drug of first choice for the therapy of generalized and focal epilepsies, including special epileptic syndromes. The drug is usually well tolerated, rare serious complications may occur in some patients, including hemorrhagic pancreatitis, coagulapathies, bone marrow suppression, VPA-induced hepatotoxicity and encephalopathy. We report a case of VPA-associated encephalopathy without hyperammonemia in a 3-year-old girl with Pallister-Killian-Syndrom, combined with a mild hepatopathy and thrombopathy. After withdrawal of VPA, the clinical symptoms and the electroencephalography-alterations vanished rapidly.

Simultaneous toxicities in a child on multiple anticonvulsants

It is rare to develop simultaneous toxicities while on anticonvulsants. This article presents a 3(1/2)-year-old child on valproic acid, lamotrigine, and phenytoin who developed simultaneous hepatotoxicity and bone marrow toxicity during a parainfluenza virus type 3 infection. These toxicities resolved after the cessation of anticonvulsants, and her seizures were managed acutely with scheduled lorazepam. This article discusses the possibility that simultaneous use of valproic acid, lamotrigine, and phenytoin could give this combination of toxicities and that concurrent viral infection may increase this risk.

Oral valproic acid for epilepsy--long-term experience in therapy and side effects

Valproic acid (VPA) is considered to be a drug of first choice and one of the most frequently-prescribed antiepileptic drugs worldwide for the therapy of generalized and focal epilepsies, including special epileptic. It is a broad-spectrum antiepileptic drug and is usually well tolerated. Rarely, serious complications may occur in some patients, including hemorrhagic pancreatitis, coagulopathies, bone marrow suppression, VPA-induced hepatotoxicity and encephalopathy, but there is still a lack of knowledge about the incidence and occurrence of these special side effects. Additionally, the consequences for VPA therapy and indication are more or less unclear. By literature review and own data this review addresses some of the challenges of VPA therapy and its side effects, which are not unique to epilepsy in childhood.

Hematologic problems in psychosomatic medicine

Vitamin B12 deficiency is associated with problems in cognition, mood, psychosis, and less commonly, anxiety. Folate deficiency primarily is associated with problems in mood. Patients who have sickle cell disease, a disease of chronic pain, experience difficulties with depression, anxiety, stigma, and are at risk for substance abuse and dependence. Patients with hemophilia have benefited from advances in treatment; however, their morbidity and mortality were compounded in those who received blood products contaminated with HIV, or hepatitis B and C. Psychiatrists who practice psychosomatic medicine should expect to encounter patients with the above problems, as they are frequently seen in medical settings. Finally, most of the commonly used psychotropic medications have uncommon but potentially important hematologic side effects or may interact with the anticoagulants used in medically ill patients.

Intravenous sodium valproate versus diazepam infusion for the control of refractory status epilepticus in children: a randomized controlled trial

An open-label, randomized controlled study was conducted at a tertiary care teaching hospital to compare efficacy and safety of intravenous sodium valproate versus diazepam infusion for control of refractory status epilepticus. Forty children with refractory status epilepticus were randomized to receive either intravenous sodium valproate or diazepam infusion. Refractory status epilepticus was controlled in 80% of the valproate and 85% of the diazepam patients. The median time to control refractory status epilepticus was less in the valproate group (5 minutes) than the diazepam group (17 minutes; P < .001). None of the patients in the valproate group required ventilation or developed hypotension, whereas in the diazepam group 60% required ventilation and 50% developed hypotension after starting diazepam infusion. No adverse effects on liver functions were seen with valproate. It is concluded that intravenous sodium valproate is an effective alternative to diazepam infusion in controlling refractory status epilepticus in children and is free of respiratory depression and hypotension.

Reversible hepatotoxicity, pancreatitis, coagulation disorder and simultaneous bone marrow suppression with valproate in a 2-year-old girl

Valproic acid (VPA) is considered to be a drug of first choice for the therapy of generalized and focal epilepsies, including special epileptic syndromes like the WEST-syndrome. The drug is usually well tolerated; rare serious complications may occur in some patients, including haemorrhagic pancreatitis, coagulapathies, bone marrow suppression, VPA-induced hepatotoxicity and encephalopathy. We report a case of combined appearance of several severe VPA-associated side effects in a two- and a half-year-old girl with lissencephaly.

Epilepsy in patients with brain tumours: epidemiology, mechanisms, and management

Epilepsy is common in patients with brain tumours and can substantially affect daily life, even if the tumour is under control. Several factors affect the mechanism of seizures in brain tumours, including tumour type, tumour location, and peritumoral and genetic changes. Prophylactic use of antiepileptic drugs is not recommended, and potential interactions between antiepileptic and chemotherapeutic agents persuades against the use of enzyme-inducing antiepileptic drugs. Multidrug-resistance proteins prevent the access of antiepileptic drugs into brain parenchyma, which partly explains why seizures are frequently refractory to treatment. Lamotrigine, valproic acid, and topiramate are first-line treatments of choice; if insufficient, add-on treatment with levetiracetam or gabapentin can be recommended. On the basis of clinical studies, we prefer to start treatment with valproic acid, adding levetiracetam if necessary. Risks of cognitive side-effects with antiepileptic drugs can add to previous damage by surgery or radiotherapy, and therefore appropriate choice and dose of antiepileptic drug is crucial.