Differential display PCR reveals novel targets for the mood-stabilizing drug valproate including the molecular chaperone GRP78.
Differential display polymerase chain reaction was used to identify genes regulated by the mood-stabilizing drug valproate (VPA). Four differentially displayed valproate-regulated gene fragments were isolated in rat cerebral cortex after i.p. injection of sodium VPA (300 mg/kg) for 3 weeks, and their expression was confirmed by Northern and slot blot analysis in rat cerebral cortex and C6 glioma cells. Sequencing analysis revealed three previously unidentified cDNA fragments in addition to a sequence with 100% homology with a molecular chaperone, 78-kDa glucose-regulated protein (GRP78). VPA treatment did not increase mRNA expression of 70-kDa heat shock protein, which is a related stress-induced molecular chaperone protein. All four candidate genes, including GRP78, showed similar VPA concentration-dependent increases in mRNA abundance. Another commonly prescribed mood-stabilizing anticonvulsant, carbamazepine, also increased GRP78 mRNA expression in C6 glioma cells, whereas lithium had no effect at doses up to 2 mM. Immunoblotting revealed that GRP78 protein levels were also increased in C6 glioma cells treated with VPA under the same conditions. Nuclear runoff analysis showed that VPA increased GRP78 gene transcription. Because GRP78 possesses molecular chaperone activity, binds Ca2+ in the endoplasmic reticulum, and protects cells from the deleterious effects of damaged proteins, the present findings suggest that VPA (and possibly carbamazepine) treatment may target one or more of these processes. (+info)
Does withdrawal of different antiepileptic drugs have different effects on seizure recurrence? Further results from the MRC Antiepileptic Drug Withdrawal Study.
One thousand and thirteen patients, in remission of epilepsy for at least 2 years, were randomized to continued therapy or slow withdrawal over 6 months and were followed up for a median period of 5 years. At the time of randomization 83% of patients were receiving monotherapy with carbamazepine (237 patients), phenobarbitone/primidone (72 patients), phenytoin (184 patients) or valproate (228 patients) in low doses, and plasma levels were below the usual optimal range. The most important factor determining seizure recurrence was continued therapy, which was the case for barbiturates, phenytoin and valproate. There was no significant difference for patients taking carbamazepine at randomization, because of a low rate of recurrence in those withdrawing treatment. The difference between carbamazepine and other drugs was not explained by differences in covariate prognostic factors. There was no evidence that withdrawal of phenobarbitone was associated with withdrawal seizures. These data provide unique evidence for the effectiveness of standard antiepileptic drugs as monotherapy. The results for carbamazepine may be open to a number of interpretations. (+info)
Perphenazine distribution in a postmortem case.
The case of a 34-year-old, mentally challenged, Caucasian female found dead in a group home is presented. Empty containers of perphenazine and valproic acid were found next to her bed. The perphenazine had been prescribed to another patient. No anatomic cause of death was determined at autopsy. Comprehensive testing of the heart blood for ethanol and drugs identified perphenazine at a concentration of 4.4 mg/L and valproic acid at a concentration of 950 mg/L. The distribution of perphenazine in other specimens was consistent with previously reported phenothiazine cases. The medical examiner ruled that the cause of death in this case was multiple drug intoxication and the manner of death was suicide. (+info)
Effects of valproate and other antiepileptic drugs on brain glutamate, glutamine, and GABA in patients with refractory complex partial seizures.
Preclinical studies suggested valproate increased brain gamma-aminobutyric acid (GABA) with no major effects on brain glutamate or glutamine. Valproate increased human cerebrospinal fluid GABA and glutamine in some studies; others reported no effect. In vivo measurements of glutamate, glutamine, and GABA were made of a 14 cm3volume in the occipital cortex using a1H spectroscopy with a 2.1 Tesla magnetic resonance spectrometer and an 8 cm surface coil. Ten control subjects and 14 patients with refractory complex partial seizures were examined. Brain glutamine concentrations were above normal in three of five patients taking valproate and two of nine taking carbamazepine or phenytoin. Mean glutamine levels of patients taking valproate were higher than control subjects and patients taking carbamazepine or phenytoin. Brain glutamate concentrations were above normal in four of nine patients taking phenytoin or carbamazepine and two of five taking valproate. Brain GABA levels were below normal in four of nine patients taking carbamazepine or phenytoin and one of five taking valproate. Above normal glutamate or below normal GABA was present in nine of 14 patients and may contribute to their refractory epilepsy. Increased brain glutamine associated with valproate therapy may reflect mild hyperammonemia. (+info)
Pharmacoeconomic and health outcome comparison of lithium and divalproex in a VA geriatric nursing home population: influence of drug-related morbidity on total cost of treatment.
OBJECTIVE: Clinicians use mood stabilizers for treating agitation in older patients, but limited information is available regarding side effects and costs in clinical practice. Total costs of treatment were assessed for a subset of geriatric patients receiving either lithium carbonate or divalproex sodium for agitation. STUDY DESIGN: Retrospective cohort examination of the medical records of 72 patients, 55 years of age or older, in a Veterans Administration long-term, skilled nursing care facility, with a diagnosis of dementia or bipolar affective disorder or both. PATIENTS AND METHODS: Patients treated with lithium or divalproex during the previous 4 years (1994-1997) were evaluated. Quantitative information was collected and compared regarding routine care, including cost of treatment and laboratory monitoring; and occurrence of adverse events and associated diagnostic and treatment measurements. RESULTS: Routine care costs for the 2 groups were similar. The lower annual acquisition cost per patient-year for lithium ($15 vs $339 for divalproex) was offset by higher laboratory monitoring costs associated with its administration ($278 vs $53 for divalproex). Examining the adverse events showed that the lithium group had more medication-related adverse events (32 total) than the divalproex group (10 total) and more severe occurrences, including 6 cases requiring medical intensive care unit (MICU) hospitalization. The total mean cost of treating drug-related mild-to-moderate morbidity was $3472 for lithium and $672 for divalproex. An additional cost per admission of $12,910 ($77,462 for all 6 cases) increased total morbidity-related expenditures in the lithium group to $80,934. CONCLUSIONS: Treating geriatric patients with lithium requires careful monitoring because of side effects. Staffing and resource limitations of a skilled nursing care facility may compromise optimal lithium monitoring in elderly patients. The collected data indicated that divalproex does not result in as many as or as severe adverse events and is, therefore, a safer treatment. The use of lithium was not only more expensive (on average $2875 more per patient) than treatment with divalproex but, more importantly, it was associated with poorer patient outcomes. (+info)
Panipenem, a carbapenem antibiotic, enhances the glucuronidation of intravenously administered valproic acid in rats.
Previously, a significant decrease in the trough plasma-concentration of valproic acid (VPA) owing to the concomitant administration of panipenem (PAPM)/betamipron, a carbapenem antibiotic, in epileptic patients was reported. To determine the site and mechanism of the drug interaction between VPA and PAPM, we performed in vivo and in vitro experiments using rats. A 30 mg/kg bolus dose of VPA was given i.v. to normal Sprague-Dawley rats, nephrectomized rats, and hepatectomized rats, with and without prior treatment of PAPM. PAPM treatment resulted in a significant reduction of biological half-life and a significant increase of total body clearance in normal rats. The effects of PAPM on the disposition kinetics of VPA were also observed in nephrectomized rats, whereas hepatectomy abolished the interaction completely. Thus, the site of interaction was identified as the liver. At steady state, PAPM treatment significantly increased total body clearance, the biliary excretion rate of VPA glucuronide, and the apparent metabolic clearance of VPA by glucuronidation, but did not affect the biliary excretion clearance of VPA glucuronide. Initial uptake velocity of VPA into rat hepatocytes proportionally increased as a function of VPA concentration added and was not affected by PAPM. The plasma-unbound fraction of VPA in vitro was not altered by PAPM. These data demonstrate that PAPM does not affect the uptake of VPA into the liver, the plasma-unbound fraction, and the excretion process of VPA glucuronide. Consequently, PAPM appears to enhance the rate of metabolism of VPA to VPA glucuronide in the liver. (+info)
Bipolar disorder in old age.
OBJECTIVE: To review the classification, clinical characteristics, and epidemiology of bipolar disorders in old age with a special focus on neurologic comorbidity, high mortality, and management. QUALITY OF EVIDENCE: Most available data is gleaned from retrospective chart reviews and cohort studies. Treatment recommendations are based on evidence from younger populations and a few anecdotal case reports and series involving elderly people. MAIN MESSAGE: While relatively rare in the community setting, mania in old age frequently leads to hospitalization. It is associated with late-onset neurologic disorders (especially cerebrovascular disease) involving the right hemisphere and orbitofrontal cortex. Prognosis is relatively poor; morbidity and mortality rates are high. Management of bipolarity includes cautious use of mood stabilizers, especially lithium and divalproex. CONCLUSIONS: Mania in old age should trigger a careful assessment of underlying neurologic disease, especially cerebrovascular disease. Close clinical follow up is essential. (+info)
A case of fever following antiepileptic treatment.
A 23-year-old female patient treated with 900 mg oxcarbazepine for complex partial seizures is presented. Good seizure control and slight fever were noted a few weeks after drug administration. Reduction of oxcarbazepine and replacement with valproate resulted in a transient normothermia. Because of fever reappearance, vigabatrin was added and valproate was gradually reduced. Seizures reappeared, but the body temperature fell below 37 degrees C. Substitution of valproate for lamotrigine resulted in seizure control but abnormal body temperature (37- 37.6 degrees C) was noted again. Repeated hospital admission for clinical and laboratory investigation before any change of treatment revealed no other abnormal findings. The patient's abnormal temperature possibly reflects a derangement of high-level temperature control. (+info)