Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clonazepam or 5-(2-chlorphenyl)-1, 3-dihydro-7-nitro-2H-1,4benzodiazepin-2-one, is a close structural and pharmacological relative of nitrazepam. It has a broad spectrum of activity against the various types of epilepsy, and is effective in many patients whose condition has proved resistant to other antiepileptic drugs. Its chief uses are in status epilepticus, in which intravenous clonazepam may replace diazepam as the drug of first choice, and in the minor motor seizures of childhood, particularly petit mal absences, the Lennox-Gastaut syndrome and infantile spasms. Clonazepam is also at least as effective as current treatment in psychomotor and myoclonic epilepsies, but seems unlikely to replace phenytoin and the barbiturates in the treatment of grand mal or focal motor seizures except in patients resistant to standard therapy. Initial success with clonazepam can be followed by loss of effect, but benefit can often be restored, at least initially, by temporary interruption and re-institution of treatment. Side-effects are common with clonazepam. Most patients experience drowsiness and fatigue, which are frequent causes of withdrawal, together with lesser incidences of ataxia, dystonia, hypotonia, and hyperactivity. These effects usually disappear with continued therapy, and are minimised by gradual introduction of the drug over 2-4 weeks. Hypersalivation and excessive bronchial secretion may be a problem in children and infants.
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PMID:Clonazepam: a review of its pharmacological properties and therapeutic efficacy in epilepsy. 97 34

1. This study presents the results of the preliminary screening of vigabatrin as add-on therapy in an open, non-controlled multicentre study in children with refractory epilepsy. 2. There were 135 children, with an age range of 2 months-12 years. Main seizure type was partial in 42%, generalized in 29%, Lennox-Gastaut syndrome in 19% and West syndrome in 10%. 3. Vigabatrin was added onto current antiepileptic treatment in an initially recommended dose of 40-80 mg kg-1 day-1. However, the doses were frequently increased when tolerance allowed it, and the final mean dose used was 87 mg kg-1 day-1 (27-600). 4. A 75% to 100% reduction in seizure frequency was observed in 25% of patients (11 patients became seizure free) and 50 to 75% decrease in a further 13%. Efficacy was better in partial seizures, with good to excellent results in 49% of patients. The use of high doses, above 100 mg kg-1 day, was not associated with greater efficacy in this preliminary study. 5. No side effects were reported in 79% of patients. Agitation and insomnia were observed in 8.8% and somnolence in 6%. Other adverse events included ataxia (2.2%), nausea (2.2%) and increased appetite (1%). A moderate and transient decrease in haemoglobin was reported in six patients from the same centre; these patients were all receiving very high doses of vigabatrin (250 to 600 mg kg-1 day-1). 6. Vigabatrin thus appears to be a safe antiepileptic drug that may be effective in the treatment of severe epilepsy in children.
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PMID:Vigabatrin in the treatment of epilepsy in children. 275 1

Lamotrigine is an antiepileptic drug which is believed to suppress seizures by inhibiting the release of excitatory neurotransmitters. Efficacy has been demonstrated for lamotrigine as add-on therapy to existing regimens in patients with resistant partial seizures. Total seizure frequency was reduced by 17 to 59% compared with placebo, and 13 to 67% of patients experienced reductions of > or = 50% in seizure frequency. Secondarily generalised tonic-clonic seizures respond well to lamotrigine, and there is preliminary evidence of improvement in patients with primary generalised seizures, Lennox-Gastaut syndrome and in children with multiple seizure types. Seizure control has been maintained in patients who have continued to receive lamotrigine as monotherapy after discontinuation of other medications. Results of one trial suggest similar efficacy for lamotrigine monotherapy as for carbamazepine, but confirmation of its use in this setting awaits more extensive controlled comparisons with established agents. Adverse events associated with lamotrigine as add-on therapy are typical of antiepileptic drugs, namely dizziness, ataxia and other CNS-related symptoms. Rash, which has occurred in 10% of patients in placebo-controlled trials, may be severe and its appearance has led to discontinuation of therapy in 1% of patients. Lamotrigine appears well tolerated in the longer term, but this facet of its profile requires further monitoring. Influences of valproic acid and enzyme-inducing anti-epileptics on lamotrigine eliminate necessitate dosage modification of lamotrigine. Conversely, lamotrigine has little apparent influence on the pharmacokinetics of other agents, although it may increase plasma concentrations of the active metabolite of carbamazepine during concomitant administration. Thus, lamotrigine permits improved seizure control in some patients with refractory partial seizures, and may prove to be especially effective in secondarily generalised tonic-clonic seizures. As is usual at this stage in a drug's development, several aspects of the profile of lamotrigine are incompletely defined, notably its efficacy in other seizure types, in children, as monotherapy, and its longer term tolerability. Nonetheless, lamotrigine presently offers a worthwhile alternative for the physician confronted with the challenge of treating patients with intractable partial seizures with or without secondarily generalised seizures, and shows potential for broader applications in other areas of epilepsy management.
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PMID:Lamotrigine. A review of its pharmacological properties and clinical efficacy in epilepsy. 769 4

The antiepileptic effect of vigabatrin (gamma-vinyl GABA, VGB) in children has been demonstrated in controlled and open studies. According to the literature, results were good to excellent in partial seizures (with and without becoming secondarily generalized) and promising in infantile spasms (IS). In patients with myoclonic epilepsies of early childhood and especially those with Lennox-Gastaut syndrome (LGS), the effect of VGB has been investigated only to a limited extent and the pattern of response was variable. The present open, add-on, dose-ranging study was initiated to assess the long-term effect and safety of VGB in a cohort of 20 children with LGS who were not responding sufficiently to first-line drug monotherapy with valproate (VPA) instead of adding classical second-line antiepileptic drugs [AEDs: benzodiazepines (BZD), phenobarbital (PB), primidone (PRM)], which usually are associated with rapid diminution of their antiepileptic properties and a high frequency of side effects. Eighty-five percent of children experienced a 50-100% reduction in seizure frequency, even after dose reduction of VPA. No serious side effects occurred except in 1 patient who experienced dyskinesia. Mood changes, sedation, ataxia, and hypersalivation, well-known complications of other AEDs, were not observed.
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PMID:Gamma-vinyl-GABA (vigabatrin) in the therapy of Lennox-Gastaut syndrome: an open study. 792 71

One hundred twenty children aged 10 months to 16 years 9 months were included in three studies with lamotrigine (LTG): a single-blind study (n = 60), a pharmacokinetic study (n = 23), and a compassionate group (n = 37). At 3 months, 11 patients had become seizure-free and 34 had > 50% decrease in seizure frequency. The best results involved absence epilepsy, Lennox-Gastaut syndrome (LGS), and other symptomatic generalized epilepsy. Forty-two patients were followed > 1 year, 22 for a mean of 2.2 years, and there was no significant increase in seizure frequency as compared with 3-month follow-up. Fourteen patients became seizure-free for > 6 months; all except 1 had generalized epilepsy. For 12 patients, treatment could be reduced to monotherapy, but for those with valproate (VPA) comedication LTG dosage had to be increased; 25% of patients with VPA monotherapy exhibited skin rash, appearing 3-18 days after starting LTG. For 4 patients, LTG could be reintroduced after VPA was withdrawn. Ten patients had ataxia and/or drowsiness and 2 had vomiting. For all other patients, tolerance was excellent.
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PMID:Lamotrigine in treatment of 120 children with epilepsy. 815 58

Lamotrigine is an antiepileptic agent which blocks voltage-dependent sodium channels, thereby preventing excitatory neurotransmitter release. Clinical evidence indicates that lamotrigine is effective against partial and secondarily generalised tonic-clonic seizures, as well as idiopathic (primary) generalised epilepsy. As monotherapy, lamotrigine 100 to 300 mg/day has similar medium term (30 to 48 weeks) efficacy to carbamazepine 300 to 1400 mg/day and phenytoin 300 mg/day against partial onset seizures and idiopathic generalised tonic-clonic seizures in adults with newly diagnosed epilepsy, and appears to be better tolerated than the older agents. As adjunctive therapy, lamotrigine (50 to 500 mg/day) has shown efficacy in short term ( < or = 6-months) placebo-controlled studies in adults with refractory partial epilepsy, reducing total seizure frequency (by < or = 60%) and producing improvement ( > or = 50% reduction in seizure frequency) in < or = 67% of patients. Both simple and complex partial seizures and secondarily generalised tonic-clonic seizures are reduced by lamotrigine, with generalised seizures (particularly absence seizures, atonic seizures and Lennox-Gastaut syndrome) tending to be more responsive than partial seizures. This reduction in seizure frequency is sustained on long term ( < or = 3 years) therapy and is reportedly accompanied by an improvement in psychological well-being. In children with refractory multiple seizure types, lamotrigine ( < or = 15 mg/kg/day; 400 mg/day) has proved effective as add-on therapy, with approximately equal to 40% of patients showing > or = 50% reductions in seizure frequency and approximately equal to 10 % achieving abolition of seizures after 3 months' treatment. Generalised seizures, including atypical and typical absence seizures, atonic and tonic seizures and Lennox-Gastaut syndrome are most responsive. The most common adverse events associated with lamotrigine are primarily neurological, gastrointestinal and dermatological. Maculopapular or erythematous skin rash, occasionally severe, occurs in approximately equal to 10% of patients and is the most common cause of treatment withdrawal. The risk of rash can, however, be minimised through adoption of a low, slow dosage titration schedule on initiating therapy. As monotherapy, lamotrigine produces less drowsiness than carbamazepine or phenytoin, and less asthenia and ataxia than phenytoin. Clinical experience would therefore suggest that lamotrigine is a particularly effective and generally well tolerated broad-spectrum agent for adjunctive treatment of both partial epilepsy and idiopathic generalised epilepsy in adults and children. Initial indications point to the drug filling an increasingly important future role in the monotherapy of newly diagnosed epilepsy.
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PMID:Lamotrigine. An update of its pharmacology and therapeutic use in epilepsy. 853 54

Lamotrigine (LTG) inhibits repetitive high frequency firing in depolarised neurones by selectively prolonging slow inactivation of the sodium channel, thereby suppressing the release of excitatory amino acids. It has been shown to be effective in 11 pivotal double-blind add-on trials in patients with refractory partial seizures with or without secondary generalisation. Subsequent anecdotal data support its efficacy for typical and atypical absences, myoclonic jerks, tonic or clonic seizures, Lennox-Gastaut syndrome and infantile spasms. Most recently LTG has been compared with carbamazepine and phenytoin in double-blind trials in patients with newly diagnosed partial and primary and secondary generalised tonic-clonic seizures. At the doses used, its efficacy was similar to the older agents for all seizure types, but LTG was better tolerated than both of the older agents. The commonest side-effects with LTG include headache, nausea, diplopia, dizziness, ataxia and tremor. Rash occurs in fewer than 5% patients. Its incidence can be reduced by starting treatment with a low dose, particularly in patients receiving concomitant sodium valproate which inhibits LTG metabolism. Enzyme inducers, such as carbamazepine, phenytoin and phenobarbital, accelerate its elimination, but LTG itself has no effect on hepatic metabolic processes. A pharmacodynamic interaction with carbamazepine necessitates a dosage reduction in some patients when LTG is introduced. LTG is a new antiepileptic agent with a long elimination half-life, a broad spectrum of activity, and a wide therapeutic ratio.
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PMID:Lamotrigine--an update. 895 Dec 13

The effects of topiramate in 15 patients with drug refractory epilepsy or Lennox-Gastaut syndrome were assessed in an open, add-on prospective study. After a follow-up of 14-21 months, six patients are still on topiramate (mean dosage 583 mg/day, range 400-800 mg/day), and nine have discontinued treatment because of adverse events (n = 6), inefficacy (n = 2) or poor compliance (n = 1). Nine patients (69%) continued to have > or = 50% reduction in seizure frequency during the last two months of treatment, and one has been seizure-free for the last 19 months. The most common adverse events were somnolence, weight loss, mental slowing, fatigue, ataxia and irritability. Most of these events were reversible, but withdrawal of treatment was required in six cases as a result of ataxia (two patients), somnolence, metabolic acidosis, irritability or psychotic symptoms (one patient each). It is concluded that topiramate is a valuable agent for long-term management of refractory epilepsy.
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PMID:Efficacy and safety of topiramate in refractory epilepsy: a long-term prospective trial. 897 50

The introduction on the French market of vigabatrin, gabapentin and lamotrigine has considerably diversified our conventional therapeutical schemes in epilepsies, as will be as amplified by the arrivals of topiramate, tiagabine and oxcarbazepine. Compared to the conventional drugs, these new products present more favorable pharmacokinetics, no or very weak interactions and a better tolerability, specially regarding the cognitive field. They should be used according to their spectrum of activity, function of their modes of action. In add-on trials on partial epilepsy patients all these new products have shown efficacy on partial and secondarily generalized seizures. Seizure frequency is reduced by at least 50 p. 100 in 30 to 50 p. 100 of the patients. A substantial number of patients can be rendered seizure-free with vigabatrin. Lamotrigine has a broader spectrum, as it is also efficacious on the different seizure types of generalized, symptomatic or idiopathic epilepsies. Main adverse events are non-specific central nervous system disturbances such as dizziness, drowsiness, ataxia, tremor or diplopia. More specifically, vigabatrin may induce weight gain and requires closer supervision in case of psychiatric history; lamotrigine which has also probable antidepressant properties, may induce skin rashs, rarely severe. Further data are needed for gabapentin which is now used at daily dosages which are two to three times those used in the initial studies. Gabamimetic agents may be worsening in some cases of generalized epilepsies, more specially on absence and myoclonic seizures. The most obvious benefits, some patients becoming seizure-free, are obtained in cases of intermediate severity, with a bitherapy including one of these new drugs. Developments in children are often delayed. Nevertheless the prognosis, including cognitive outcome, is considerably improved in infantile spasms with vigabatrin and in Lennox-Gastaut syndrome with lamotrigine and felbamate, the latter being highly toxic. For the moment in France, authorities have limited the use of all these new antiepileptic drugs to adjunctive therapy in epilepsies resisting to conventional drugs. But recent monotherapy data show similar efficacy with better tolerability. Once the pivotal, controlled studies have enabled to obtain regulatory approval, all these compounds must undergo a large-scale evaluation phase in order to better define dosages, long-term tolerability, indications and eventual contra-indications in the various epileptic syndromes, including children.
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PMID:[Therapeutic options provided by new antiepileptic drugs]. 929 53

Six studies are cited to demonstrate that topiramate is effective as adjunctive therapy for refractory partial-onset seizures in adults. Subsequent studies indicate that topiramate is also effective as monotherapy in adults and as adjunctive therapy for partial-onset seizures in children, tonic-clonic seizures of nonfocal origin in children and adults, and drop attacks in Lennox-Gastaut syndrome. Adverse effects for adults and children included dizziness, fatigue, ataxia, confusion, somnolence, nephrolithiasis, paresthesia, and weight loss. More adverse effects were observed at higher doses. Topiramate exhibits rapid absorption, long duration of action, and minimal interaction with other antiepileptic drugs.
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PMID:Topiramate. 1053 Jun 97


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