Side effects of valproate

Dermatoprotective effect of Moringa oleifera leaf extract on sodium valproate-induced skin damage in rats

Valproic acid is an antiepileptic drug associated with skin-related issues like excessive hair growth, hair loss, and skin rashes. In contrast, Moringa oleifera, rich in nutrients and antioxidants, is gaining popularity worldwide for its medicinal properties. The protective properties of M. oleifera extract against skin-related side effects caused by valproic acid were investigated. Female rats were divided into control groups and experimental groups such as moringa, sodium valproate, and sodium valproate + moringa groups. A 70% ethanolic extract of moringa (0.3 g/kg/day) was given to moringa groups, and a single dose of sodium valproate (0.5 g/kg/day) was given to valproate groups for 15 days. In the skin samples, antioxidant parameters (such as glutathione, glutathione-S-transferase, superoxide dismutase, catalase, and total antioxidant capacity), as well as oxidant parameters representing oxidative stress (i.e. lipid peroxidation, sialic acid, nitric oxide, reactive oxygen species, and total oxidant capacity), were examined. Additionally, boron, hydroxyproline, sodium-potassium ATPase, and tissue factor values were determined. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was also carried out for protein analysis in the skin samples. The results showed that moringa could increase glutathione, total antioxidant capacity, sodium-potassium ATPase, and boron levels, while decreasing lipid peroxidation, sialic acid, nitric oxide, total oxidant capacity, reactive oxygen species, hydroxyproline, and tissue factor levels. These findings imply that moringa possesses the potential to mitigate dermatological side effects.

Risk factors of hyperammonemia in epilepsy patients with valproic acid therapy

BACKGROUND

Hyperammonemia can occur after acute overdose or chronic use of valproic acid (VPA). Although VPA-related hyperammonemic encephalopathy (VHE) is a rare complication of VPA therapy, early recognition of VHE and identifying its risk factors are important because VHE can lead to loss of consciousness and increased seizure frequency.

PURPOSE

The purpose of our study is to evaluate the risk factors of hyperammonemia in epilepsy patients during treatment with VPA therapy.

METHODS

We reviewed the medical records of 1084 adult patients with epilepsy and enrolled 116 patients with VPA therapy who had results of blood levels of ammonia over a 3-year period. Hyperammonemia was defined as a blood ammonia level exceeding 80 µg/dL. Correlations of blood levels of ammonia with dosages and blood levels of VPA were evaluated. We further performed univariate and multivariate linear regression analyses to identify risk factors for hyperammonemia in epilepsy patients treated with VPA therapy.

RESULTS

Blood levels of ammonia were well correlated with dosages of VPA (p = 0.036), but not with blood levels of VPA (p = 0.463). Hyperammonemia was more common in patients with higher VPA dosage and higher total drug loads of concurrent antiseizure medications (ASMs). Hyperammonemia was also associated with the use of topiramate and phenobarbital. In multivariate analysis, we identified total drug load of ASMs (p = 0.003) and use of topiramate (p = 0.007) as independent predictors of hyperammonemia. Four patients (4/116, 3.4 %) had clinical symptoms of VHE. Three of them had hyperammonemia while the other patient had normal blood level of ammonia with a high blood level of VPA.

CONCLUSION

Our study shows that higher total drug loads of concurrent ASMs and use of topiramate were independent risk factors of hyperammonemia in epilepsy patients with VPA therapy. Although the incidence of VHE was not high in our study, clinicians should be aware of this potential adverse effect of VPA therapy, especially in patients with polytherapy of ASMs including topiramate.

Individually tailored dosage regimen of full-spectrum Cannabis extracts for autistic core and comorbid symptoms: a real-life report of multi-symptomatic benefits

Autism Spectrum Disorders (ASD) may significantly impact the well-being of patients and their families. The therapeutic use of cannabis for ASD has gained interest due to its promising results and low side effects, but a consensus on treatment guidelines is lacking. In this study, we conducted a retrospective analysis of 20 patients with autistic symptoms who were treated with full-spectrum cannabis extracts (FCEs) in a response-based, individually-tailored dosage regimen. The daily dosage and relative proportions of cannabidiol (CBD) and tetrahydrocannabinol (THC) were adjusted based on treatment results following periodic clinical evaluation. Most patients (80%) were treated for a minimum of 6 months. We have used a novel, detailed online patient- or caregiver-reported outcome survey that inquired about core and comorbid symptoms, and quality of life. We also reviewed patients' clinical files, and no individual condition within the autistic spectrum was excluded. This real-life approach enabled us to gain a clearer appraisal of the ample scope of benefits that FCEs can provide for ASD patients and their families. Eighteen patients started with a CBD-rich FCE titrating protocol, and in three of them, the CBD-rich (CBD-dominant) FCE was gradually complemented with low doses of a THC-rich (THC-dominant) FCE based on observed effects. Two other patients have used throughout treatment a blend of two FCEs, one CBD-rich and the other THC-rich. The outcomes were mainly positive for most symptoms, and only one patient from each of the two above-mentioned situations displayed important side effects one who has used only CBD-rich FCE throughout the treatment, and another who has used a blend of CBD-Rich and THC-rich FCEs. Therefore, after FCE treatment, 18 out of 20 patients showed improvement in most core and comorbid symptoms of autism, and in quality of life for patients and their families. For them, side effects were mild and infrequent. Additionally, we show, for the first time, that allotriophagy (Pica) can be treated by FCEs. Other medications were reduced or completely discontinued in most cases. Based on our findings, we propose guidelines for individually tailored dosage regimens that may be adapted to locally available qualified FCEs and guide further clinical trials.

Antipsychotics and Medical Comorbidity: A Retrospective Study in an Urban Outpatient Psychiatry Clinic

Patients with psychotic disorders have increased rates of medical comorbidities. In this cross-sectional study, we investigated the relationship between antipsychotics and medical comorbidities among patients with psychotic disorders in an urban psychiatry clinic in Atlanta, Georgia (n = 860). Each antipsychotic group was compared to a group of patients from the same sample who were not on any antipsychotic, and logistic regression models were constructed for each comorbidity. Ziprasidone was associated with diabetes (aOR 2.56, 95% CI 1.03-6.38) and obesity (aOR 3.19, 95% CI 1.37-7.41). Aripiprazole was associated with obesity (aOR 2.39, 95% CI 1.27-4.51). Clozapine was associated with GERD (aOR 3.59, 95% CI 1.11-11.61), movement disorders (aOR 4.44, 95% CI 1.02-19.32), and arrythmias (4.89, 95% CI 1.44-16.64). Two antipsychotics that are considered weight neutral, ziprasidone and aripiprazole, were associated with cardiometabolic comorbidities. This study suggests that research is warranted to study the association between antipsychotics, medical comorbidity, and psychotic symptom burden.

Valproic-induced Fanconi syndrome: Clinical features, risk factors, diagnosis and management

Objective

Although Fanconi syndrome (FS) induced by valproate (VPA) has occasionally been reported, the detailed clinical features of the disease remain unclear. The aim of this study was to elucidate the clinical features of patients with VPA-induced FS.

Methods

We searched Chinese and English databases for all original studies, clinical reports, and case reports on VPA-induced FS published before March 2022.

Results

A total of 29 articles including 54 patients (28 males and 24 females) were included. The patients had a median age of 7 years (range 2–34 years), had severely disabled (87.0%), tube feeding (64.8%), and received an average of 1.8 medications other than VPA. The median duration of VPA treatment was 4 years (range 0.7–15.5). Pathological fractures (25.9%), unexplained fever (11.1%), muscle weakness (9.3%), and edema (9.3%) were the most common symptoms, while 18 patients were diagnosed in incidental laboratory tests. Blood tests revealed hypokalemia (69.2%), hypophosphatemia (98.0%), and hypouricemia (93.3%). Urinalysis revealed glucosuria (96.1%), proteinuria (100.0%), generalized hyperaminoaciduria (100.0 %), β2 macroglobulin (100.0%). Decreased percent total reabsorption of phosphate (%TRP) found in 94.1% of patients, and increased fractional excretion of uric acid (FEUA) were found in 100% of patients. The median time to resolution of FS after discontinuation of drug therapy was 3 months (range 0.25–18).

Conclusions

The possibility of FS needs to be considered with long-term VPA administration, especially in young, tube-fed, severely disabled patients who are co-administered with anticonvulsants. Patients receiving VPA should have regular blood and urine tests. Abnormal laboratory values returned to normal levels after VPA discontinuation.

Green synthesis of gold nanoparticles using an antiepileptic plant extract: in vitro biological and photo-catalytic activities

Gold nanoparticles are one of the widely used metallic nanoparticle having unique surface plasmon characteristic, offers major utility in biomedical and therapeutic fields. However, chemically synthesized nanoparticle creates toxicity in the living organisms and contradicts the eco-friendly and cost-effective nature. So, developing greener synthetic route for synthesis of gold nanoparticle using natural materials is an enthralling field of research for its effectiveness in synthesizing eco-friendly, non-toxic materials. Moreover, biological components attached as stabilizing agent can exert its own effect along with the advantages of nanoparticle conjugation. In this work, we used for the first time methanolic leaf extract of Moringa oleifera as this fraction of M. oleifera exerts a neuroactive modulation against seizure as evidenced by earlier literature. The green gold nanoparticles synthesized were characterized by different characterization tools, dynamic light scattering and transmission electron microscopy techniques etc. Prepared nanoparticles were biologically (antioxidant, antimicrobial and blood cytotoxicity) characterized to screen their further utility in therapeutic strategies. Characteristics and activities of green gold nanoparticles were compared with conventional citrate stabilized gold nanoparticles. It was observed that green gold nanoparticles prepared using M. oleifera show less cytotoxicity and helps in regeneration of neuronal cells in animal model study. It establishes the fact that conjugation of different plant extract fraction for stabilization of gold nanoparticle may be responsible factor for enhancement of bioactive nature of green gold nanoparticle. In addition, the green gold nanoparticle show efficient photo-catalytic efficiency. Development of such bioactive gold nanoparticles will lead to functional materials for biomedical and therapeutic applications.

Gold nanoparticles are one of the widely used metallic nanoparticle having unique surface plasmon characteristic, offers major utility in biomedical and therapeutic fields.

Differential Expression of Multiple Disease-Related Protein Groups Induced by Valproic Acid in Human SH-SY5Y Neuroblastoma Cells

Valproic acid (VPA) is a multifunctional medication used for the treatment of epilepsy, mania associated with bipolar disorder, and migraine. The pharmacological effects of VPA involve a variety of neurotransmitter and cell signaling systems, but the molecular mechanisms underlying its clinical efficacy is to date largely unknown. In this study, we used the isobaric tags for relative and absolute quantitation shotgun proteomic analysis to screen differentially expressed proteins in VPA-treated SH-SY5Y cells. We identified changes in the expression levels of multiple proteins involved in Alzheimer’s disease, Parkinson’s disease, chromatin remodeling, controlling gene expression via the vitamin D receptor, ribosome biogenesis, ubiquitin-mediated proteolysis, and the mitochondrial oxidative phosphorylation and electron transport chain. Our data indicate that VPA may modulate the differential expression of proteins involved in mitochondrial function and vitamin D receptor-mediated chromatin transcriptional regulation and proteins implicated in the pathogenesis of neurodegenerative diseases.

Effects of CBD-Enriched Cannabis sativa Extract on Autism Spectrum Disorder Symptoms: An Observational Study of 18 Participants Undergoing Compassionate Use

Autism Spectrum Disorders comprise conditions that may affect cognitive development, motor skills, social interaction, communication, and behavior. This set of functional deficits often results in lack of independence for the diagnosed individuals, and severe distress for patients, families, and caregivers. There is a mounting body of evidence indicating the effectiveness of pure cannabidiol (CBD) and CBD-enriched Cannabis sativa extract (CE) for the treatment of autistic symptoms in refractory epilepsy patients. There is also increasing data support for the hypothesis that non-epileptic autism shares underlying etiological mechanisms with epilepsy. Here we report an observational study with a cohort of 18 autistic patients undergoing treatment with compassionate use of standardized CBD-enriched CE (with a CBD to THC ratio of 75/1). Among the 15 patients who adhered to the treatment (10 non-epileptic and five epileptic) only one patient showed lack of improvement in autistic symptoms. Due to adverse effects, three patients discontinued CE use before 1 month. After 6-9 months of treatment, most patients, including epileptic and non-epileptic, showed some level of improvement in more than one of the eight symptom categories evaluated: Attention Deficit/Hyperactivity Disorder; Behavioral Disorders; Motor Deficits; Autonomy Deficits; Communication and Social Interaction Deficits; Cognitive Deficits; Sleep Disorders and Seizures, with very infrequent and mild adverse effects. The strongest improvements were reported for Seizures, Attention Deficit/Hyperactivity Disorder, Sleep Disorders, and Communication and Social Interaction Deficits. This was especially true for the 10 non-epileptic patients, nine of which presented improvement equal to or above 30% in at least one of the eight categories, six presented improvement of 30% or more in at least two categories and four presented improvement equal to or above 30% in at least four symptom categories. Ten out of the 15 patients were using other medicines, and nine of these were able to keep the improvements even after reducing or withdrawing other medications. The results reported here are very promising and indicate that CBD-enriched CE may ameliorate multiple ASD symptoms even in non-epileptic patients, with substantial increase in life quality for both ASD patients and caretakers.

Anemia secondary to the use of sodium valproate for preventing postoperative seizures in a 79-year-old man: A case report

RATIONALE

Sodium valproate is a widely used antiepileptic drug and also used to prevent postoperative seizures in neurosurgery. Anemia caused by sodium valproate is occasionally reported and most are from pediatric patients.

PATIENT CONCERNS

We present the case of a 79-year-old man who developed anemia in the setting of a short-term sodium valproate therapy for the prevention of postoperative seizures.

DIAGNOSIS

By testing complete blood count we found anemia and hepatic enzyme elevations arising after 3-week standard dose sodium valproate therapy for preventing postoperative seizures. Our investigations ruled out most of the known causes of anemia including infection, uncontrolled bleeding, underlying systemic disease, malnutrition, immune hemolytic anemia, and neoplasia. On the drug's discontinuation as diagnostic therapy the patient's hemoglobin began to rise spontaneously and liver function returned to normal. Thus anemia secondary to sodium valproate was considered as the most likely diagnosis.

INTERVENTIONS

Sodium valproate was suspended and the patient was transfused with concentrated red blood cells.

OUTCOMES

The hemoglobin recovered obviously on the drug's discontinuation.

LESSONS

Hematologic toxicity of sodium valproate can occur quickly. Regular complete blood count test helps to make prompt diagnosis and drug discontinuation leads to the recovery.

Restoration of Megalin-Mediated Clearance of Alveolar Protein as a Novel Therapeutic Approach for Acute Lung Injury

Acute respiratory distress syndrome constitutes a significant disease burden with regard to both morbidity and mortality. Current therapies are mostly supportive and do not address the underlying pathophysiologic mechanisms. Removal of protein-rich alveolar edema-a clinical hallmark of acute respiratory distress syndrome-is critical for survival. Here, we describe a transforming growth factor (TGF)-β-triggered mechanism, in which megalin, the primary mediator of alveolar protein transport, is negatively regulated by glycogen synthase kinase (GSK) 3β, with protein phosphatase 1 and nuclear inhibitor of protein phosphatase 1 being involved in the signaling cascade. Inhibition of GSK3β rescued transepithelial protein clearance in primary alveolar epithelial cells after TGF-β treatment. Moreover, in a bleomycin-based model of acute lung injury, megalin^+/- animals (the megalin^-/- variant is lethal due to postnatal respiratory failure) showed a marked increase in intra-alveolar protein and more severe lung injury compared with wild-type littermates. In contrast, wild-type mice treated with the clinically relevant GSK3β inhibitors, tideglusib and valproate, exhibited significantly decreased alveolar protein concentrations, which was associated with improved lung function and histopathology. Together, we discovered that the TGF-β-GSK3β-megalin axis is centrally involved in disturbances of alveolar protein clearance in acute lung injury and provide preclinical evidence for therapeutic efficacy of GSK3β inhibition.

Hyperammonemia induced by prophylactic administration of antiepileptic drugs during the perioperative period of craniotomy

BACKGROUND

Antiepileptic drugs (AEDs) are increasingly used prophylactically during the perioperative period to prevent epilepsy in patients undergoing craniotomy. Evidence concerning the use of AEDs and the incidence, extent and risk factors of hyperammonemia induced by different types of AEDs is lacking.

METHODS

Patients were divided into groups with 3 different AED regimens, levetiracetam, valproate and carbamazepine regimens, and the blood ammonia concentration and liver and coagulation functions were assessed during the perioperative period.

RESULTS

Sixty-five patients were enrolled consecutively and the postoperative hyperammonemia was found in 46 patients (70.77%), and 45 (97.83%) were asymptomatic. A total of 80.95% of the patients using valproate developed hyperammonemia, and the postoperative blood ammonia concentration continued to rise in 61.90% of these patients. Additionally, valproate had the least impact on liver enzymes. The synthetic function of the liver in patients with higher concentrations of preoperative blood ammonia was more seriously damaged than that in patients with normal postoperative ammonia concentrations.

CONCLUSIONS

Selection of AED for patients undergoing craniotomy should be based on the individual medical situation. Carbamazepine may be a proper choice for the majority of these patients, while valproate is likely to be more appropriate for patients with abnormal liver aminotransferases.

Inositol depletion, GSK3 inhibition and bipolar disorder

Valproic acid and lithium are widely used to treat bipolar disorder, a severe illness characterized by cycles of mania and depression. However, their efficacy is limited, and treatment is often accompanied by serious side effects. The therapeutic mechanisms of these drugs are not understood, hampering the development of more effective treatments. Among the plethora of biochemical effects of the drugs, those that are common to both may be more related to therapeutic efficacy. Two common outcomes include inositol depletion and GSK3 inhibition, which have been proposed to explain the efficacy of both valproic acid and lithium. Here, we discuss the inositol depletion and GSK3 inhibition hypotheses, and introduce a unified model suggesting that inositol depletion and GSK3 inhibition are inter-related.

Vitamin U has a protective effect on valproic acid-induced renal damage due to its anti-oxidant, anti-inflammatory, and anti-fibrotic properties

The aim of present study was to investigate the effect of vitamin U (vit U, S-methylmethionine) on oxidative stress, inflammation, and fibrosis within the context of valproic acid (VPA)-induced renal damage. In this study, female Sprague Dawley rats were randomly divided into four groups: Group I consisted of intact animals, group II was given vit U (50 mg/kg/day, by gavage), group III was given VPA (500 mg/kg/day, intraperitonally), and group IV was given VPA + vit U. The animals were treated by vit U 1 h prior to treatment with VPA every day for 15 days. The following results were obtained in vit U + VPA-treated rats: (i) the protective effect of vit U on renal damage was shown by a significant decrease in histopathological changes and an increase in Na(+)/K(+)-ATPase activity; (ii) anti-oxidant property of vit U was demonstrated by a decrease in malondialdehyde levels and xanthine oxidase activity and an increase in glutathione levels, catalase and superoxide dismutase activities; (iii) anti-inflammatory property of vit U was demonstrated by a decrease in tumor necrosis factor-α, interleukin-1β, monocyte chemoattractant protein-1 levels, and adenosine deaminase activity; (iv) anti-fibrotic effect of vit U was shown by a decrease in transforming growth factor-β, collagen-1 levels, and arginase activity. Collectively, these data show that VPA is a promoter of inflammation, oxidative stress, and fibrosis which resulted in renal damage. Vit U can be proposed as a potential candidate for preventing renal damage which arose during the therapeutic usage of VPA.

Risk factors of hyperammonemia in patients with epilepsy under valproic acid therapy

Hyperammonemia has been reported to be associated with patients who receive valproic acid (VPA) therapy. This study aimed to determine the risk factors for hyperammonemia in patients with epilepsy treated with VPA. One hundred and fifty-eight adult patients with epilepsy aged older than 17 years who received VPA therapy were enrolled into this study. Blood samples were taken during the interictal state and analyzed for the blood level of ammonia. Statistical analysis was conducted between different groups of patients. The results showed that the frequency of hyperammonemia associated with VPA therapy was 27.8% (ammonia level >93 µg/dL), and 5.1% of the patients had severe hyperammonemia (ammonia level >150 µg/dL). The blood ammonia level was significantly correlated with the dosage of VPA and the plasma concentration of VPA. An increase of 1 mg in the dosage of VPA increased the risk of hyperammonemia by 0.1%. In addition, combination treatment with liver enzyme inducing antiepileptic drugs (AEDs) and antipsychotic drugs increased the risk of hyperammonemia. In conclusion, the use of VPA in adult patients with epilepsy was associated with a dose-dependent increase in blood concentrations of ammonia. Combination treatment with liver enzyme-inducing AEDs and antipsychotic drugs increased the risk of VPA-induced hyperammonemia. Most of the patients with VPA-induced hyperammonemia were asymptomatic; however, if patients taking VPA present with symptoms such as nausea, fatigue, somnolence, ataxia, and consciousness disturbance, the blood ammonia level should be measured.

Efficacy and mechanism of anticonvulsant drugs in migraine

Anticonvulsants represent one of the main substance classes used for the preventive treatment of migraine. Efficacy has been demonstrated in randomized placebo-controlled trials for topiramate and valproic acid including divalproex sodium. In the case of topiramate, efficacy has recently been proven for chronic migraine and even medication overuse headache, questioning the established concept of medication withdrawal. However, preventive treatment with anticonvulsants is frequently hampered by side effects that occasionally require treatment discontinuation. In addition, these data indicate that some anticonvulsant drugs are effective in migraine, while a number are clearly not useful. Effective anticonvulsants, such as topiramate and valproate, target nociceptive trigeminovascular and trigeminothalamic dural pathways or mechanisms involved in cortical spreading depression. Dissecting out how the anticonvulsants that do not work differ mechanistically from those that do will almost certainly provide avenues through which one can develop new treatments to bring to patients with migraine.

Maintenance therapies in bipolar disorders

OBJECTIVE

Bipolar disorder is an inherently recurrent disorder, requiring maintenance preventive treatments in the vast majority of patients. The authors review the data on maintenance treatments in bipolar disorder, highlighting the controlled trial literature.

METHODS

Literature review using PubMed, Medline, and a hand search of relevant literature.

RESULTS

Over the last decade, a number of effective maintenance treatments for bipolar disorder have been developed with an evidence base for second-generation antipsychotics and some anticonvulsants. Increasing numbers of patients, therefore, are appropriately treated with multiple medications as a maintenance regimen. For some medications, maintenance treatment has been demonstrated in randomized controlled trials for both monotherapy and in combination with other mood stabilizers. Lithium continues as our oldest well-established maintenance treatment in bipolar disorder with somewhat better efficacy in preventing mania than depression. Lamotrigine, olanzapine, and quetiapine have bimodal efficacy in preventing both mania and depression, although lamotrigine's efficacy is more robust in preventing depression and olanzapine's efficacy is greater in preventing mania. Aripiprazole, ziprasidone, and risperidone long-acting injection all prevent mania, but not depression. Less controlled investigations have suggested some evidence of maintenance mood stabilization with carbamazepine, oxcarbazepine, and adjunctive psychotherapy.

CONCLUSIONS

Despite the number of agents with demonstrated efficacy as maintenance treatments in bipolar disorder, optimal treatment regimens are still a combination of evidence-based therapy in combination with individualized creative treatment algorithms.

Anticonvulsant-induced rickets and nephrocalcinosis

Reported here is the case of a severely disabled young girl who developed Fanconi syndrome secondary to long-term valproic acid administration, ultimately leading to hypophosphatemic rickets. Although nephrocalcinosis is not a common feature in patients with proximal tubulopathy, the patient presented also with this condition, and the concomitant use of another anticonvulsant might have potentiated this condition. The purpose of this report is to increase awareness among healthcare providers of such rare but significant complications associated with anticonvulsants.

The influence of valproic acid treatment on hair and serum zinc levels and serum biotinidase activity

Some of the side effects that develop during long-term valproic acid (VPA) treatment are similar to symptoms of zinc and partial biotinidase deficiencies. This situation suggests an association between these side effects and biotinidase and/or zinc deficiencies. In 32 pediatric patients (22 females, 10 males) receiving VPA treatment, hair and serum zinc levels and serum biotinidase activity (BA) were measured prior to and in the 3rd and 6th months of treatment. Also, serum VPA levels were measured in the 3rd and 6th months of treatment. The mean serum and hair zinc levels were found to be reduced in the 3rd and 6th months of treatment as compared with the pre-treatment values, while the mean serum BA was lower than the pre-treatment values in the 3rd month of treatment, but returned to initial values in the 6th month of treatment. In the 3rd and 6th months of treatment, patients complaining about hair loss had lower hair and serum zinc levels and serum BA but greater mean serum VPA than those who did not. However, the differences between parameters were not statistically significant. Our findings suggest that hair loss in patients can be attributed to zinc and BA depletion within the first 3 months, and to zinc depletion only by the 6th month.

Solid-state forms of sodium valproate, active component of the anticonvulsant drug epilim

The results of the first detailed and systematic investigation of the solid-state forms of sodium valproate, one of the most potent and widely used anticonvulsant medicines, are presented. By using wet and dry methods, eight solid forms of varying stability in air were obtained and characterized. Three extremely hygroscopic polycrystalline hydrates, Na(C8H15O2) X H2O (form A), Na(C8H15O2) X xH2O (form B), and Na(C8H15O2) X yH2O (form D), three acid-stabilized stoichiometric solvates, Na3(C8H15O2)3(C8H16O2)H2O (form C), Na(C8H15O2)(C8H16O2) (form E), and Na3(C8H15O2)3(C8H16O2) X 2H2O (form F), the pure anhydrous salt Na(C8H15O2) (form H), and an additional unstable thermal intermediate Na3(C8H15O2)3(C8H16O2)0.5 (form G) were prepared. Under ambient conditions, forms A and B as well as the commercially available compound appear as very hygroscopic white powders. Form C is less hygroscopic, while forms E and F are stable and are not hygroscopic. Partial stabilization of forms A and B can be achieved by evacuation and pressing, which results in a lower hydrate D, or after a heating-cooling cycle, resulting in crystallization of the anhydrous salt H. Addition of one molecule of valproic acid and saturation with one molecule of water of forms A and B results in the less hygroscopic form C. Addition to form C of a second water molecule affords form F, which is not hygroscopic and is indefinitely stable. The symmetric structure and medium alkyl chain length of the valproate ion are some of the probable reasons for the presence of a number of solid solvates: in its most stable conformation, the valproate ion cannot simultaneously pack efficiently and interact strongly through the negatively charged carboxylate group without leaving voids in the crystalline lattice. The conformational flexibility of the aliphatic chains probably aids the penetration of water molecules, which results in a strong affinity for the absorption of water.

Safety and tolerability of emerging pharmacological treatments for bipolar disorder

OBJECTIVES

Over the past few years numerous new agents have been examined for their efficacy in bipolar disorder (BPD). New antiepileptic agents and atypical antipsychotics currently form the bulk of these emerging agents. As the armamentarium for treating BPD increases, it allows for the possibility of choosing drugs on the basis of their tolerability as well as their efficacy, rather than on efficacy alone.

METHODS

Efficacy data for newer antiepileptic drugs (lamotrigine, topiramate, gabapentin, oxcarbazepine) and atypical antipsychotics (olanzapine, clozapine, risperidone, quetiapine, ziprasidone, aripiprazole) are briefly reviewed. The article focuses on relative safety and tolerability of these agents.

RESULTS

In general, most of these newer agents have better side effect and tolerability profiles than older agents commonly used to treat BPD (lithium, valproate, carbamazepine); however, these must be weighed against efficacy demonstrated to date in randomized, controlled trials. Cognitive impairment is a concern with topiramate, weight gain and risk of diabetes with some of the atypical antipsychotic agents, and rash with lamotrigine.

CONCLUSIONS

Side effects of newer emerging agents for the treatment of BPD can be effectively managed and the risks reduced by instituting practical strategies early in management.

Secondary renal Fanconi syndrome caused by valproate therapy

Although renal Fanconi syndrome resulting from valproate (VPA) has occasionally been reported, the detailed clinical characteristics of this disease remain unclear. To clarify the clinical features of patients with VPA-induced Fanconi syndrome, we analyzed the clinical and laboratory data of seven affected patients. All patients were children, were severely disabled and required tube feeding. Five patients required treatment with multiple anticonvulsant agents. Hypophosphatemia and hypouricemia were found in all patients. Mild proteinuria, increased excretion of urinary beta2-microglobulin (beta2MG) and generalized hyperaminoaciduria were present in all patients. The renal biopsy of one patient exhibited tubulointerstitial nephritis without any structural abnormalities of the mitochondria in proximal renal tubular cells. All patients recovered from the Fanconi syndrome after the cessation of VPA therapy without any long-term renal sequellae. These results indicate that young age and being severely disabled with tube feeding and anticonvulsant polytherapy are contributory factors to the development of VPA-induced Fanconi syndrome. Serum phosphate and uric acid concentrations and urinary beta2MG levels in addition to serum electrolytes and urinalysis should be examined regularly in patients receiving VPA therapy, especially in those with the contributory factors outlined above. Patients with Fanconi syndrome caused by VPA have a favorable renal outcome.

Topiramate-valproate-induced hyperammonemic encephalopathy syndrome: case report

A 15-year-old boy with inverted duplication of chromosome 15 was admitted for acute onset of irritability, increasing sleepiness, and worsening of seizures. He had been on valproate and other anti-convulsants. However, he was found to have hyperammonemia within 2 weeks after the addition of low-dose topiramate to valproate. He recovered within 7 days after discontinuation of valproate. Topiramate was tailed off. The reintroduction of valproate monotherapy caused hyperammonemia again without clinical features of encephalopathy. He also developed anticonvulsant hypersensitivity syndrome following the use of phenytoin. We propose the term topiramate-valproate-induced hyperammonemic encephalopathy syndrome to include the following features: excessive sleepiness or somnolence, aggravation of seizures, hyperammonemia, and absence of triphasic waves on electroencephalography in any individual on simultaneous topiramate-valproate therapy. The ammonia level ranged from 1.5 to 2 times normal. The serum valproate level might be within the therapeutic range. The possible mechanism is topiramate-induced aggravation of all the known complications of valproate monotherapy. This condition is reversible with cessation of either valproate or topiramate.

Gingival enlargement in children treated with antiepileptics

This study was conducted to determine the occurrence, severity, and risk factors of gingival enlargement in children treated with valproate and other nonvalproate antiepileptic drugs. A cross-sectional study was carried out in which data obtained from 68 epileptic children under treatment were compared with those from 50 controls. A structured questionnaire was used to collect data on patients' demographics, dental and oral hygiene practices, and medication history. Gingival enlargement, gingival index, plaque index, and probing depth were measured to assess periodontal health. The chi-square and Fisher exact tests were used in statistical analysis. In case of significance, a detailed chi-square analysis was carried out to determine the origin of the difference. Patients in both the valproate and nonvalproate groups showed significantly higher gingival enlargement, gingival index, plaque scores, and pocketing (P < .001 and P < .01, respectively) than the control group. In the valproate group, the duration of the treatment had a significant effect on gingival enlargement (P < .001) but not on gingival index, plaque index, and probing depth values (P > .05). Toothbrushing was most frequent in the control group (P = .000) and more frequent in the valproate group than the nonvalproate group (P = .024). Our study showed significant differences regarding gingival enlargement in children treated with valproate. These findings illustrate that epileptic children on valproate are at risk of periodontal problems.

Lamotrigine as first-line drug in childhood absence epilepsy: a clinical and neurophysiological study

To investigate to which extent lamotrigine (LTG) may be effective and tolerated as a monotherapy for the treatment of newly diagnosed childhood absence seizures and, secondly, to evaluate the efficacy of this drug on the circadian interictal generalized epileptiform discharges, 20 consecutive newly diagnosed patients (five males, 15 females), aged 3-10 years (mean 6.9 years), affected by childhood absence epilepsy, were administered LTG as first-line drug at the initial dose of 0.5 mg/kg/day for 2 weeks, followed by 1.0 mg/kg/day for an additional 2 weeks. Thereafter, doses have been increased in 1-mg/kg/day increments up to 9-12 mg/kg/day in accordance with the clinical response. Each patient underwent an ambulatory (24 h) EEG monitoring before starting LTG therapy (time 0) and during the maintenance period at the end of LTG titration (time 1). After a mean follow-up period of 10.8 months (range 3-28 months), a 100% seizure control was obtained in 11 children (55.5%), a more than 75% seizure decrease was present in four (20%), and a >50% seizure decrease in five (25%), with a mean LTG dose of 6.2 mg/kg/day (range 1.2-11) in the controlled group. Adverse events were present in three patients (15%); they were generally mild and transient. Our series confirms that LTG monotherapy may control typical childhood absence seizures in about half the children as well as it may decrease interictal generalized spike and wave discharges both in seizure-free and uncontrolled patients. The slow titration phase of the drug due to the risk of the skin rash may eventually reduce compliance.

Evaluation of neuroprotection by lithium and valproic acid against ouabain-induced cell damage

BACKGROUND

The pathophysiology of manic-depression may be associated with dysregulation of ion homeostasis. Ouabain is a potent inhibitor of the sodium-potassium adenosine triphosphatase and has been purported to mimic abnormalities seen in acute mania. As manic episodes are believed to be neurotoxic and mood stabilizers have recently been implicated as neuroprotectants, it is of interest to determine if lithium and valproic acid antagonize ouabain-induced neurotoxicity.

METHODS

Human neuroblastoma SH-SY5Y cells were differentiated for 12 days then pretreated with lithium or valproic acid for 24 h and then challenged with a 10 microM ouabain insult. Cellular damage was assessed with lactate dehydrogenase (LDH) release, and apoptotic potential of ouabain was evaluated with DNA fragmentation.

RESULTS

Ouabain significantly increased LDH release after 72 h of treatment. Lithium pretreatment at 1 mM diminished ouabain-induced LDH release. Valproic acid alone at 100 and 1000 micrograms/mL significantly increased LDH release from the cells. Furthermore, it significantly potentiated ouabain-induced LDH release. DNA fragmentation suggests that ouabain induces apoptosis.

CONCLUSIONS

Lithium at the therapeutic level of 1 mM limits the extent of cellular damage caused by 10 microM ouabain in SH-SY5Y cells as measured by LDH release. Valproic acid alone at the therapeutic concentration of 100 micrograms/mL induces LDH release and does not prevent ouabain-induced LDH release.

Do structural properties explain the anticonvulsant activity of valproate metabolites? A QSAR analysis

PURPOSE

Differences in potency among valproate (VPA) metabolites could be explained by structural properties. Therefore, a quantitative structure-activity relation (QSAR) analysis was performed to study the relation between structural parameters and the effect of the following VPA metabolites: 4-en-VPA, 2-en-VPA, 3-en-VPA, 2,4'-dien-VPA, 4,4'-dien-VPA, 4-hydroxy-VPA, 3-ceto-VPA, 3-hydroxy-VPA, 5-hydroxy-VPA, and propylglutaric acid.

METHODS

By using the CAChe program package for biomolecules (Oxford Molecular, Ltd), we performed molecular modeling. The anticonvulsant activity determined on the threshold for maximal electroconvulsions in mice was obtained from a study of Löscher and Nau. Structural parameters were compared between metabolites with a double bond and metabolites with oxygen at either side chain (unpaired Student's t test). A single linear regression analysis between each structural parameter and the relative anticonvulsant potency was also performed.

RESULTS

Similar parameters were found between the cis and trans and R and S isomers. Biologic activity and most of the structural parameters were significantly different between metabolites with a double bond and metabolites with oxygen at either side chain. Activity was directly related to log P(oct) (r(2) = 0.77) and to reactivity parameters and was inversely related to stability parameters and to molecular weight and surface. The most potent metabolites had a log P(oct) value of higher than 2 units.

CONCLUSIONS

Similar data were identified between cis and trans, and R and S isomers of VPA metabolites. Anticonvulsant activity was mainly related to log P(oct), probably reflecting the ability of VPA metabolites to cross the blood-brain barrier.

Topiramate enhances the risk of valproate-associated side effects in three children

PURPOSE

We present three children with severe therapy-refractory epilepsy who tolerated valproate (VPA) well in various combinations with other antiepileptic drugs (AEDs) but developed typical VPA side effects in combination with topiramate (TPM).

METHODS

The clinical symptoms began with apathy in all three children; two of them also had hypothermia. Furthermore all children had elevated blood ammonia levels, one child in combination with increased liver transaminases and one with thrombocytopenia.

RESULTS

All children recovered completely after discontinuation of VPA or TPM.

CONCLUSIONS

TPM seems likely to enhance the risk of side effects usually attributed to VPA and not described in TPM monotherapy. Our case reports suggest that possible adverse effects of VPA should be given particular attention when VPA is combined with TPM.

Valproate, but not lamotrigine, induces ovarian morphological changes in Wistar rats

Valproate (VPA) medication is associated with development of polycystic ovaries, menstrual disorders and hormonal changes in women with epilepsy. We sought to determine if changes in the ovaries also occurred in an animal model without epilepsy, and whether this effect could be related to a carcinogenic effect expressed by overexpression of p53. A potentially alternative antiepileptic drug, lamotrigine (LTG), was evaluated simultaneously. To this end, female Wistar rats were fed perorally with VPA 400 mg/kg/day (n = 15), VPA 600 mg/kg/day (n = 20), LTG 10 mg/kg/day (n = 15) or control solution (n = 15) for 90-95 days. There was a significant, dose-dependent increase in the number of follicular cysts, reduction in the number of corpora lutea and reduction of ovarian weight in the VPA group. No ovarian pathology was observed in the LTG group. In neither of the groups were morphological changes seen in other organs, nor was there any overexpression of the tumor suppressor gene p53 found. An alternative antiepileptic drug, LTG, showed no ovarian pathology, and there were no light microscopic changes in other organs, or evidence of pathologic p53 overexpression in the LTG-treated animals.

Hematologic toxicity of sodium valproate

PURPOSE

Sodium valproate is a commonly used anticonvulsant in the management of childhood refractory epilepsy with good response rates and acceptable toxicity. Hepatotoxicity is the most widely recognized toxicity. With the use of higher drug levels to achieve adequate seizure control, hematologic toxicity is being increasingly encountered, and the pediatric hematologist is consulted for these problems in the pre- or perioperative setting. The purpose of this article is to characterize the various hematologic toxicities encountered in a clinical setting and to provide guidelines to assist in the management of these patients.

METHODS

A literature review was undertaken to identify the hematologic toxicities of valproate used as monotherapy or polytherapy. Key words used in the search were valproate, hematology, and bleeding.

RESULTS

Valproate can cause direct bone marrow suppression leading to aplastic anemia or peripheral cytopenia affecting one or more cell lines. Occasional fatal bone marrow failure, myelodysplasia, and a clinical picture resembling acute promyelocytic leukemia have also been seen. Thrombocytopenia, macrocytosis, neutropenia, and pure red cell aplasia can occur but are not reported to be life-threatening. A bleeding diathesis associated with valproate use may include thrombocytopenia, abnormal platelet function, and acquired von Willebrand disease type I.

CONCLUSIONS

Hematologic toxicities of valproate are common, vary in onset and severity, are recurrent, transient, or persistent, and usually occur with a serum valproate level greater than 100 microg/mL. In most situations, even when highly clinically significant, they can be reversed with dosage reduction; drug discontinuation is rarely required. Potential adverse effects such as thrombocytopenia and leukopenia are easily detected by laboratory monitoring, which should be continued indefinitely at least on a quarterly basis. Caution for elective surgery is advised; preoperative coagulation studies should be done, including platelet function studies and von Willebrand factor levels. Perioperative use of DDAVP to increase von Willebrand factor levels and improve platelet function is appropriate in some cases.

Cross sensitivity of skin rashes with antiepileptic drugs

BACKGROUND

Skin rashes are a well known complication of antiepileptic drug (AED) treatment. It has also been recognized that some patients will develop rashes from multiple AEDs (cross sensitivity). There are very few studies that have attempted to determine the frequency of cross sensitivity among AEDs.

METHODS

Charts of all patients attending an epilepsy outpatient clinic were reviewed to determine AED exposure and the occurrence of a rash from AEDs.

RESULTS

633 patients had 1,875 exposures to 14 AEDs. Rashes occurred from carbamazepine (N = 27), phenytoin (N = 21), phenobarbital (N = 5) and lamotrigine (N = 1). A rash from 2 or more AEDs occurred in 14 patients and involved predominantly carbamazepine and phenytoin. Among the patients exposed to both phenytoin and carbamazepine 10/17 (58%) of patients with a rash from phenytoin also had a rash from carbamazepine; conversely 10/25 (40%) patients with a carbamazepine rash also had a rash from phenytoin. 4/5 patients with a phenobarbital rash were sensitive to carbamazepine and/or phenytoin. Amongst the other most commonly used AEDs no rashes occurred from valproic acid or clobazam.

CONCLUSIONS

The cross sensitivity rate for rashes involving carbamazepine and phenytoin is 40-58%. If a rash develops from either of these AEDs, valproate or clobazam are safe alternatives.

The platelet aggregation in children with epilepsy receiving valproic acid

This study was performed to evaluate the aggregation changes in the whole blood samples of children with epilepsy receiving valproic acid. A total of 25 patients and 15 healthy volunteer adults were included in the study. Platelet aggregation study was performed in whole blood by impedance aggregometry. Platelet counts, the bleeding times, and clotting times of the patients were within normal limits. The aggregation time and maximum aggregation values revealed no significant difference except for those with 2 mu g/ml collagen (p < 0.01) between the two groups. Serum valproic acid levels of the children did not correlate with the maximum aggregation values induced by different concentrations of aggregating agents except for 20 mu M ADP (r = -0.430, p < 0.05). We concluded that the use of valproic acid does not result in thrombocytopenia and platelet dysfunction within therapeutic limits and the drug is reliable in the management of epilepsy.

The emerging role of valproate in bipolar disorder and other psychiatric disorders

Although valproate, a simple branched-chain fatty acid, is generally considered to be an antiepileptic agent, a large literature dating back to 1966 describes its use in primary psychiatric disorders. The significant role that gamma-aminobutyric acid plays in mood provided the rationale to examine valproate in this regard. Numerous uncontrolled as well as placebo- and lithium-controlled studies verified the drug's efficacy in the short-term management of bipolar and schizoaffective disorders. The response appears to be independent of response to traditional therapies such as lithium, neuroleptics, and carbamazepine, and may be maintained for extended periods of time. Valproate should be considered not only in patients with mood disorders who are intolerant of or nonresponsive to traditional therapies, but also in those with rapid cycling, electroencephalographic abnormalities, head trauma antedating the onset of psychiatric illness, or any other factor suggesting an organic component. Preliminary uncontrolled studies suggest that the drug may also eventually play a role in the management of panic disorder and behavioral dyscontrol (agitation, aggression, temper outbursts). Its adverse event profile is well known from years of experience in the management of epilepsy and does not appear to be altered in the presence of psychiatric disorders. Similarly, the drug-drug interaction potential of valproate is reasonably well known, although further research into interactions with psychotropic agents is warranted.

Efficacy and adverse effects of established and new antiepileptic drugs

Antiepileptic drug (AED) selection is based primarily on efficacy for specific seizure types and epileptic syndromes. However, efficacy is often similar for the different AEDs, and other properties such as adverse effects, pharmacokinetic properties, and cost may also be of importance. For idiopathic generalized epilepsies with absence, tonic-clonic, and myoclonic seizures, the AED of choice is valproate (VPA). Secondarily generalized epilepsies with tonic, atonic, and other seizure types are difficult to treat with any single AED or combination of AEDs. The AEDs of choice for absence seizures are ethosuximide (ESM) and VPA. For control of primary generalized tonic-clonic seizures, any of the other major AEDs can be effective. If VPA cannot be prescribed, carbamazepine (CBZ), phenobarbital (PB), phenytoin (PHT), or primidone (PRM) may be effective, but ESM or a benzodiazepine (BZD) must be added to control associated absence or myoclonic seizures. The AEDs of first choice for partial epilepsies with partial and secondarily generalized tonic-clonic seizures are CBZ and PHT. Increasing evidence suggests that VPA is a good alternative when CBZ and PHT fail. PB and PRM are second-choice selections because of adverse effects. A combination of two of the five standard AEDs may be necessary to treat intractable seizures, but no studies have been done to indicate an optimal combination. Other epilepsy syndromes such as neonatal and infantile epilepsies, febrile epilepsy, alcoholic epilepsy, and status epilepticus require specific AED treatment. Ultimately, AED selection must be individualized. No "drug of choice" can be named for all patients. The expected efficacy for the seizure type, the importance of the expected adverse effects, the pharmacokinetics, and the cost of the AEDs all must be weighed and discussed with the patient before a choice is made. A number of new AEDs with unique mechanisms of action, pharmacokinetic properties, and fewer adverse effects hold important promise of improved epilepsy treatment.

Valproate encephalopathy and hypocarnitinaemia in diabetic patients

Two patients with epilepsy and diabetes mellitus developed encephalopathy while on valproate monotherapy. Low plasma carnitine levels were found. Discontinuation of valproate was followed by clinical recovery and normalization of carnitine levels. Both valproate treatment and diabetes mellitus may contribute to secondary carnitine deficiency, with resultant encephalopathy. Thus, diabetic patients may be at increased risk of developing valproate encephalopathy associated with hypocarnitinaemia.

Standard approach to antiepileptic drug treatment in the United States

Antiepileptic drugs (AEDs) are administered to patients for acute and long-term treatment of seizures. Most patients with acute convulsions receive intravenous (i.v.) benzodiazepine (BZD), frequently followed by i.v. loading with phenytoin (PHT), especially when seizures continue. For patients with absence status epilepticus, BZD is usually followed by ethosuximide (ESM) or valproate (VPA). The decision to continue AED therapy is based on the likelihood that seizures will continue or recur. Once epilepsy is diagnosed, long-term treatment with AEDs is recommended, beginning with monotherapy. Two studies sponsored by the U.S. Veterans Administration (VA), which compared the efficacy of carbamazepine (CBZ), PHT, phenobarbital (PB), primidone (PRM), and VPA, recommend that most adults with recurrent partial seizures receive either CBZ or PHT. The 1992 VA study suggests that VPA is equal to CBZ or PHT in efficacy when partial seizures become secondarily generalized. Primary generalized epilepsies are most frequently treated with VPA when combinations of generalized seizures exist. ESM is prescribed most often when typical childhood absence seizures exist alone. Although many authorities do not recommend long-term treatment of childhood febrile seizures, PB is administered by some when febrile seizures have complex symptomatology. In general, AED monotherapy is currently preferred, but those with more refractory epilepsy receive polytherapy. CBZ, PHT, PB, PRM, VPA, and ESM are the primary AEDs prescribed in the United States. PHT, followed by CBZ and VPA, is the most frequently prescribed AED as both new and total prescriptions. The introduction of felbamate, gabapentin,and lamotrigine may alter these patterns in the future.

Haematological disturbances during long-term valproate therapy

A 14-year-old boy with mental retardation presented with severe thrombocytopenia, macrocytic anaemia and allergic dermatitis. He had been treated with valproate for seizures since the age of 2 years. Clinical examination showed severe purpura, mucous bleeding and extensive dermatitis. Tests to detect serum direct antiplatelet antibodies were positive and bone marrow examination revealed myelodysplastic abnormalities. Valproate was discontinued and both dermatitis and general condition of the child improved with normalization of the full blood count. This report suggests that valproate may produce both peripheral immune thrombocytopenia and severe bone marrow depression several years after the initiation of the therapy.

Hematologic manifestations of long-term valproate therapy

Sixty patients receiving long-term valproate (VPA) monotherapy were studied for hematologic side effects. All were patients in a long-term care facility and ranged in age from 2 to 29 years (mean 14.6 years). Twenty developed at least one prominent hematologic abnormality. Thrombocytopenia and macrocytosis were the most common findings. In patients with macrocytosis, platelet counts were inversely related to VPA levels. Serum B12 levels were increased in 51 of the patients. In 12 patients with macrocytosis who were extensively studied, no etiology for the increased MCV could be identified. An increased number of Pelger-Huet-like cells was noted in these 12 patients. None of the patients demonstrated hepatic dysfunction. Hematologic toxicity was never severe enough to discontinue therapy and always responded to small decrements in VPA therapy. VPA was discontinued in only 1 patient, owing to poor seizure control.

Conventional and controlled release valproate in children with epilepsy: a cross-over study comparing plasma levels and cognitive performances

We studied plasma levels and behavioural effects of a newly developed controlled release formulation of valproate (VPA-CR) in children with epilepsy. Valproate plasma levels and performances in attention and vigilance tasks were monitored during a 12-h period (daytime), both during monotherapy of conventional valproate (VPA) and 4 weeks after switching to a similar dosage of VPA-CR taken once daily. There was no significant difference between the two formulations with respect to mean diurnal trough and peak valproate plasma levels, and to mean fluctuation. The significantly higher Cmax/Cmin ratio during VPA-CR seems mainly due to low valproate plasma levels early in the morning. Neuropsychological assessment showed no significant differences, either between patients and controls, or within patients and controls when comparing the results obtained on the VPA and VPA-CR day. During both VPA and VPA-CR treatment, no correlation was found between cognitive performance and valproate plasma levels. The advantage of VPA-CR is that the once daily regimen may increase compliance and is more convenient for schoolchildren.

A comparison of valproate with carbamazepine for the treatment of complex partial seizures and secondarily generalized tonic-clonic seizures in adults. The Department of Veterans Affairs Epilepsy Cooperative Study No. 264 Group

BACKGROUND

Valproate is approved for use primarily in patients with absence seizures, but the drug has a broad spectrum of activity against seizures of all types. Partial or secondarily generalized tonic-clonic seizures are often difficult to control adequately with standard treatment, usually carbamazepine or phenytoin.

METHODS

We conducted a multicenter, double-blind trial that compared valproate with carbamazepine in the treatment of 480 adults with complex partial seizures (206 patients) or secondarily generalized tonic-clonic seizures (274 patients). The patients were randomly assigned to treatment with carbamazepine or divalproex sodium (valproate) at doses adjusted to achieve blood levels in the middle of the therapeutic range. Patients were followed for one to five years or until seizures became uncontrollable, treatment had unacceptable adverse effects, or both these events occurred.

RESULTS

For the control of secondarily generalized tonic-clonic seizures, carbamazepine and valproate were comparably effective (in 136 patients and 138 patients, respectively). For complex partial seizures, four of five outcome measures favored carbamazepine (100 patients) over valproate (106 patients): the total number of seizures (2.7 vs. 7.6, P = 0.05), the number of seizures per month (0.9 vs. 2.2, P = 0.01), the time to the first seizure (P less than 0.02), and the seizure-rating score (P = 0.04). Carbamazepine was also superior according to a composite score that combined scores for the control of seizures and for adverse effects (P less than 0.001). Valproate was associated more frequently than carbamazepine with a weight gain of more than 5.5 kg (12 lb) (20 percent vs. 8 percent, P less than 0.001), with hair loss or change in texture (12 percent vs. 6 percent, P = 0.02), and with tremor (45 percent vs. 22 percent, P less than 0.001). Rash was more often associated with carbamazepine (11 percent vs. 1 percent, P less than 0.001).

CONCLUSIONS

Valproate is as effective as carbamazepine for the treatment of generalized tonic-clonic seizures, but carbamazepine provides better control of complex partial seizures and has fewer long-term adverse effects.

Ammonia and carnitine concentrations in children treated with sodium valproate compared with other anticonvulsant drugs

Plasma ammonia was measured in 59 children requiring anticonvulsant drugs: 37 children (group 1) on sodium valproate alone or in combination with other drugs and 22 children (group 2) on drugs other than sodium valproate. Plasma ammonia was higher in group 1 children. Total and free carnitine was measured in plasma and erythrocytes of all children and in the urine of 16 children from group 1 and eight from group 2. Plasma and erythrocyte free carnitine was significantly lower in the children on sodium valproate, along with a significant increase in the ratio of acyl (bound) carnitine to free carnitine. No significant correlation was found between plasma ammonia and carnitine concentrations for either group of children. Plasma and erythrocyte concentrations were not related. Urinary free carnitine was reduced in children treated with valproate, with a significant increase in the ratio of bound to free carnitine. Carnitine supplementation is discussed.