Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cross reactivity between phenytoin, carbamazepine, and oxcarbazepine is reported. An 8 year old boy with partial seizures developed maculopapular rashes with itching on day 15 of carbamazepine therapy. After stopping carbamazepine, phenytoin 100 mg daily was prescribed two days later. On the 12th day of phenytoin therapy he developed cervical and axillary lymphadenopathy with fever. Lymph nodes revealed reactive hyperplasia. Oxcarbazepine 75 mg twice daily also resulted in oral and mucosa ulceration. The seizures were controlled without any side effects with sodium valproate 200 mg three times a day and gabapentin 300 mg twice a day. Due to the cross reactivity of aromatic anticonvulsants (phenytoin, carbamazepine, and oxcarbazepine), valproate or newer anticonvulsants should be used if a patient has sensitivity to these drugs.
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PMID:Phenytoin and carbamazepine cross reactivity: report of a case and review of literature. 1470 49

Oxcarbazepine (Trileptal, Timox) is structurally related to carbamazepine and has anticonvulsant activity. Studies suggest that the anticonvulsant activity of oxcarbazepine is mediated via the blocking of neuronal ion channels. In patients aged <18 years, the efficacy of oxcarbazepine monotherapy was similar to that of phenytoin in children with partial onset or generalised tonic-clonic seizures in a 48-week trial. Additional supporting findings demonstrated that 43-71% of patients with partial onset, generalised or undetermined epilepsy were seizure free after oxcarbazepine monotherapy (mean dosage 27.7-50 mg/kg/day; duration 1-5 years). In contrast, one small nonblind trial showed more patients treated with oxcarbazepine monotherapy than with carbamazepine monotherapy had recurrent seizures during 16 months of therapy (although the conclusions that can be drawn from this trial are limited). As adjunctive therapy, oxcarbazepine was significantly better than placebo at reducing seizure frequency in children and adolescents with refractory partial onset seizures with or without secondary generalisation: the median percentage change in partial onset seizure frequency was 35% versus 9%, respectively, during 16 weeks of therapy. In noncomparative trials of adjunctive oxcarbazepine (mean dosage of 34.5-56.7 mg/kg/day), 7-11% of patients with partial onset or generalised seizures were seizure free during treatment, and 20-54% had seizure reductions of > or =50%. Oxcarbazepine was generally well tolerated during monotherapy and adjunctive therapy; 2.5% and 10% of patients withdrew from well controlled trials of oxcarbazepine monotherapy and adjunctive therapy. Oxcarbazepine monotherapy was better tolerated than phenytoin and events observed in oxcarbazepine-treated patients were transient. Oxcarbazepine metabolism is largely unaffected by induction of the cytochrome (CYP) P450 system. However, oxcarbazepine can inhibit CYP2C19 and induce CYP3A4 and CYP3A5, thereby interfering with the metabolism of other drugs (e.g. phenytoin). In addition, oxcarbazepine decreases plasma levels of oral contraceptives and alternative contraceptive methods should be used. In conclusion, oxcarbazepine (as both monotherapy and adjunctive therapy) has shown efficacy in the treatment of partial onset seizures in children with epilepsy. Nevertheless, the generally favorable tolerability profile and relatively low potential for drug interactions of oxcarbazepine make it a valuable option in the treatment of childhood epilepsy.
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PMID:Spotlight on oxcarbazepine in epilepsy. 1473 Oct 60

Oxcarbazepine (OXC, trade names Timox, Trileptal is a new antiepileptic drug (AED) for treatment of mono- and adjunctive therapy of partial seizures with or without secondary generalization for adults and children older than 6 years of age. Although OXC was developed through structural variation of carbamazepine in order to avoid side effects from metabolites, significant differences have emerged between the two drugs. The mechanism of action mainly involves blockade of sodium currents but differs from CBZ by modulating different types of calcium channels. In contrast to CBZ, which is oxidized by the cytochrome P-450 system, OXC undergoes reductive metabolism at its ketomoiety to form MHD, which is glucuronidated and excreted in the urine. Involvement of the hepatic cytochrome P450-dependent enzymes in the metabolism of OXC is minimal. This allows for better combining of OXC with other AEDs such as valproate. In postmarketing experience of over 800,000 patient-years, OXC also showed an advantageous risk-benefit ratio. Oxcarbazepine should be preferred over CBZ and other older AEDs due to its very good efficacy and better side effect profile in children, adolescents, and adults with partial seizures.
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PMID:[How is oxcarbazepine different from carbamazpine?]. 1477 Feb 87

Oxcarbazepine (OXC, Trileptal) is a modern antiepileptic drug (AED) used as both monotherapy and adjunctive therapy for the treatment of partial seizures with or without secondary generalization in adults and children above 4 years (USA) or 6 years (Europe) of age. Although OXC has been developed through structural variation of carbamazepine (CBZ) with the intent to avoid metabolites causing side effects, significant differences have emerged between the two drugs. The mechanism of action of OXC involves mainly blockade of sodium currents but differs from CBZ by modulating different types of calcium channels. In contrast to CBZ, which is oxidized by the cytochrome P-450 system, OXC undergoes reductive metabolism at its keto moiety to form the monohydroxy derivative (MHD), which is glucuronidated and excreted in the urine. The involvement of the hepatic cytochrome P-450-dependent enzymes in the metabolism of OXC is minimal. Although it does not prevent interaction with oral contraceptives, it explains why OXC can be more effectively combined with other AEDs such as valproate compared with CBZ. Switching from CBZ to OXC normalized CBZ-associated thyroid and sexual hormone abnormalities and pathological lipid values in small patient samples. OXC is often better tolerated than CBZ and causes fewer rashes than CBZ. Add-on or substitution treatment with OXC was effective in controlled trials even when CBZ did not achieve sufficient seizure control. This constitutes compelling clinical evidence that OXC and CBZ are distinctly different medications. From postmarketing experience in over 1,000,000 patient years, OXC had an advantageous risk-benefit balance also in comparison to other new AEDs. OXC should be preferred over CBZ and other older AEDs because of its proven efficacy and excellent side effect profile in children, adolescents, and adults with partial seizures.
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PMID:What is the evidence that oxcarbazepine and carbamazepine are distinctly different antiepileptic drugs? 1538 Jan 12

SIB 1893 (a non-competitive antagonist of group I metabotropic glutamate receptors), given at 40 mg/kg (but not at 20-30 mg/kg), shortened the afterdischarge duration in amygdala-kindled rats, being ineffective on other seizure parameters - seizure severity, seizure duration, and afterdischarge threshold. Oxcarbazepine (at 7.5 mg/kg, but not at 5 mg/kg), a newer antiepileptic drug, reduced seizure severity, seizure and afterdischarge durations. When combined at ineffective doses in amygdala kindling, SIB 1893 at 20 or 30 mg/kg and oxcarbazepine at 5 mg/kg, significantly reduced seizure and afterdischarge durations. The results indicate that combinations of oxcarbazepine with antagonists of group I metabotropic glutamate receptors may offer a novel therapeutic approach in cases of drug-resistant epilepsy.
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PMID:SIB 1893, a selective mGluR5 receptor antagonist, potentiates the anticonvulsant activity of oxcarbazepine against amygdala-kindled convulsions in rats. 1552 May 1

The incidence of new-onset epilepsy is higher among the elderly, the most rapidly growing segment of the population, than in any other age group. New-onset seizures in elderly patients are typically cryptogenic or symptomatic partial seizures that require long-term treatment. Because seizures in the elderly are often readily controlled, considerations of tolerability and safety, including pharmacokinetics and the potential for drug interactions, may be as important as efficacy in the selection of an antiepileptic drug (AED). The newer AEDs introduced during the past decade offer advantages in this respect over older agents. Phenytoin is the most widely used AED in the United States, but its hepatic metabolism and associated enzyme induction, as well as its nonlinear pharmacokinetics, are particular disadvantages for elderly patients. Because of their potential effects on cognitive function, sedating AEDs such as phenobarbital and primidone have little place in the treatment of new-onset seizures in elderly patients. Carbamazepine also is an enzyme-inducing agent with significant potential for drug interactions. Among the newer AEDs, gabapentin and levetiracetam have good safety and cognitive effect profiles and do not interact with other drugs, and lamotrigine offers many of the same benefits. Oxcarbazepine has better tolerability than carbamazepine, and topiramate and zonisamide, although they have more cognitive side effects than the other new AEDs, can be considered for some elderly patients. Forthcoming data from the Veterans Affairs Cooperative Trial 428, as well as recent guidelines from the American Academy of Neurology and the American Epilepsy Society, are likely to provide support for the use of selected second-generation AEDs as first-line agents for the treatment of epilepsy in elderly patients.
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PMID:Initial treatment of epilepsy: special issues in treating the elderly. 1555 50

Antiepileptic drug (AED) treatment is associated with multiple short- and long-term side effects. Effects on endocrine function, including weight change, reproductive function, thyroid function, and bone health are examples of these side effects. Some AEDs affect weight, resulting in weight gain or loss. Levetiracetam and lamotrigine are weight-neutral agents, whereas valproate is associated with weight gain. Reproductive dysfunction is reported in women and men with epilepsy treated with AEDs. In women, the most common symptoms are hyperandrogenism, menstrual disorders with ovulatory failure, polycystic ovary-appearing ovaries or polycystic ovary syndrome, and hyperinsulinemia. These symptoms may be secondary to epilepsy or to AED treatment, particularly with valproate. In men, effects on sperm quality and motility, delayed sexual development, and small testicular size have been described in association with AED treatment. Carbamazepine reduces testosterone levels, whereas valproate increases androgen levels. Oxcarbazepine is not associated with changes in testosterone levels. Treatment with all of these agents can result in changes in sperm, including concentration, morphology, and motility. Enzyme-inducing AEDs are known to result in decreased thyroid hormones. Recent studies found reduced serum thyroid hormone concentrations in men and young girls treated with carbamazepine and oxcarbazepine. However, all patients were clinically euthyroid, and these changes were reversible after AED withdrawal. Persons with epilepsy treated with AEDs are at increased risk for fracture. Not only is this increased because of seizure activity, but also because of treatment with AEDs. AED treatment results in decreased bone mineral density, the most sensitive predictor of fracture and changes in biochemical indices of bone metabolism, including calcium, vitamin D, and markers of bone formation and resorption. Identifying each of these endocrine abnormalities is important because it may be necessary and beneficial to change AED treatment. In addition, multiple therapies exist for the treatment of polycystic ovary syndrome, infertility, and decreased bone mineral density.
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PMID:Effects of Treatment on Endocrine Function in Patients with Epilepsy. 1596 90

Oxcarbazepine (OXC) was introduced in 1990 and is now registered in 54 countries worldwide as monotherapy, as add-on treatment for partial seizures, with or without secondarily generalised seizures, and primary generalised tonic-clonic seizures. OXC and its active metabolite, monohydroxy derivative (MHD), block voltage-dependent sodium channels and may effect potassium and calcium channels. In animal models of epilepsy, OXC and MHD have efficacy similar to that of CBZ. There is no evidence for clinically important teratogenicity, mutagenicity or carcinogenicity. OXC has no effect on serum concentrations of hepatically metabolised anti-epileptic drugs (AEDs) and no clinically important interactions with common non-AEDs, other than hormonal contraceptives. MHD has low protein binding and linear pharmacokinetics. Adverse effects (AEs) are usually related to the central nervous system. Approximately three-quarters of patients who experience adverse effects with CBZ improve when switched to OXC, without loss of seizure control. The incidence of rash appears to be less than that expected with CBZ. While hyponatraemia may occur more often with OXC than with CBZ, it is rarely symptomatic. OXC is an effective and safe drug for the treatment of partial-onset and primary generalised tonic-clonic seizures. Placebo- and low-dose controlled double-blind monotherapy studies prove that OXC has anticonvulsant activity and that therapeutic dosages may be obtained with a 24 h titration in hospitalised patients, if necessary. Comparative double-blind trials show that OXC has similar efficacy to VPA, CBZ and PHT, but has advantages compared to those agents in terms of pharmacokinetics, side-effects and tolerability.
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PMID:Oxcarbazepine: current status and clinical applications. 1599 10

Oxcarbazepine is an antiepileptic drug (AED) indicated for use as monotherapy and add-on therapy in adults and children 4 years of age and older. Despite being structurally related to carbamazepine, oxcarbazepine differs substantially in its pharmacokinetic and safety profile; oxcarbazepine has a much lower risk of pharmacokinetic drug-drug interactions than carbamazepine. Carbamazepine has also been shown to induce the hepatic synthesis of sex hormone-binding globulin, thus reducing free serum testosterone levels and possibly causing erectile dysfunction (ED) in some men; these effects have not been observed with oxcarbazepine. This paper provides a discussion of recent clinical experience with men who presented in private clinical practice with complaints of ED while being treated with carbamazepine for seizure disorders. The four illustrative case studies presented in this report suggest that switching AED treatment from carbamazepine to oxcarbazepine in men with epilepsy can reduce the ED side effects observed with carbamazepine.
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PMID:Amelioration of erectile dysfunction following a switch from carbamazepine to oxcarbazepine: recent clinical experience. 1600 74

Relatively few well-designed studies have demonstrated the long-term safety and tolerability of newer antiepileptic drugs (AEDs) in a large group of children. Extensive clinical data from the worldwide Clinical Development Program (CDP) and a compassionate use program on the safety and tolerability of oxcarbazepine in children are presented. Oxcarbazepine is a newer AED that is indicated for use as monotherapy and adjunctive therapy in children (United States 4 years of age, Europe 6 years of age) with partial epilepsy. The most common adverse events (10%) in the CDP were headache (32.5%), somnolence (31.5%), vomiting (27.6%), and dizziness (23.1%), whereas in the compassionate use program (clinical practice situation), the most common adverse events (1%) reported were rash (2.7%), fatigue (1.6%), nausea (1.2%), and somnolence (1.2%). These data indicate that oxcarbazepine has a good long-term safety and tolerability profile, whether given as monotherapy or adjunctive therapy, in children with partial seizures.
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PMID:Long-term safety and tolerability of oxcarbazepine in children: a review of clinical experience. 1617 88


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