Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038220 (status epilepticus)
 7,272 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phenytoin (PHT) is considered a first or second choice in the treatment of status epilepticus that is refractory to benzodiazepines. The use of an intravenous bolus injection of PHT is hazardous due to the risk of cardiac conduction disturbances, dose-dependent side effects in general, as well as the possibility of severe necrotic lesions in case of extravasation. We compared the number and intensity of side effects and serum level profiles of a highly concentrated, non-dilutable bolus (46 mg/ml) of PHT [Fenytoin, DAK] with a dilutable standard solution (1.5 mg/ml) [Phenhydan] administered intravenously in 500 ml saline. Six healthy volunteers received both regiments (9.1 mg/kg). The diluted solution showed a curvilinear saturation curve with a lower concentration maximum (C-max) than the concentrated solution. Lower toxicity of the diluted solution was indicated by a clinical rating of side effects. Based on a higher incidence and degree of side effects following administration of the more concentrated formulation of PHT, compared with the more diluted preparation, we recommend the use of the less concentrated formulation.
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PMID:Phenytoin-loading: pharmacokinetic comparison between an intravenous bolus injection and a diluted standard solution. 157 98

In the past decade, several new antiepileptic drugs have been tested. Most recently, 5 new antiepileptic drugs have been launched onto European and US markets. These include vigabatrin, oxcarbazepine and lamotrigine in Europe, and felbamate and gabapentin in the US. In addition to these, 3 additional drugs are in the clinical investigational stage: flunarizine, fosphenytoin and stiripentol. A fourth agent is midazolam, which was originally introduced in 1986, but recently has shown effectiveness in the treatment of status epilepticus. Flunarizine is a selective calcium channel blocker that has shown anticonvulsant properties in both animal and human studies. It is a long-acting anticonvulsant that clinical studies have shown to have effects similar to those of phenytoin and carbamazepine in the treatment of partial, complex partial and generalised seizures. Fosphenytoin was developed to eliminate the poor aqueous solubility and irritant properties of intravenous phenytoin. It is rapidly converted to phenytoin after intravenous or intramuscular administration. In clinical studies, this prodrug showed minimal evidence of adverse events and no serious cardiovascular or respiratory adverse reactions. It may have a clear advantage over the present parenteral formulation of phenytoin. Midazolam is a benzodiazepine that is more potent than diazepam as a sedative, muscle relaxant and in its influence on electroencephalographic measures. It has been shown to be an effective treatment for refractory seizures in status epilepticus. Stiripentol has anticonvulsant properties as well as the ability to inhibit the cytochrome P450 system. There are significant metabolic drug interactions between stiripentol and phenytoin, carbamazepine and phenobarbital (phenobarbitone). Stiripentol has been studied in patients with partial seizures, refractory epilepsy and refractory absence seizures with some efficacious results.
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PMID:New anticonvulsant drugs. Focus on flunarizine, fosphenytoin, midazolam and stiripentol. 752 21

Status epilepticus occurs in more than 50,000 people in the United States each year and should be considered a neurologic emergency. A variety of drugs are used to treat status epilepticus, including i.v. benzodiazepines, phenytoin, and barbiturates. They are all short of being ideal, primarily because of difficulties with administration or associated toxicity. Fosphenytoin, a prodrug and phosphate ester of phenytoin, was developed to overcome the drawbacks associated with i.v. phenytoin. With its efficacy, safety, and ease of administration, fosphenytoin is a valuable option for the treatment of status epilepticus.
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PMID:Emergency treatment of status epilepticus. 864 10

Phenobarbital, diazepam, lorazepam, and phenytoin are all currently used for the treatment of acute seizures, including status epilepticus. None of these drugs is considered ideal. Fosphenytoin is a new phenytoin prodrug that fulfills many of the properties of an ideal anticonvulsant drug. The safety, tolerance, and pharmacokinetics of intramuscularly administered fosphenytoin have been evaluated in three clinical trials involving patients requiring loading or maintenance doses of phenytoin. These investigations demonstrated that fosphenytoin is rapidly and completely absorbed after injection into muscle and is quickly converted to produce therapeutic phenytoin plasma concentrations within 30 min of administration. Plasma concentrations of phenytoin achieved with i.m. fosphenytoin exceeded those associated with an equimolar dose of oral phenytoin. i.m. fosphenytoin was well tolerated both locally and systemically. Only mild and transient reactions occurred at the injection site. The most common systemic adverse events reported--somnolence, nystagmus, dizziness, and ataxia--are side effects commonly seen with phenytoin and tended to be mild. Preexisting seizure disorders remained stable. Combination treatment with i.v. diazepam or lorazepam to attain rapid seizure control and i.m. fosphenytoin to maintain the anticonvulsant effect theoretically offers many advantages for control of acute seizures and should be studied.
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PMID:Intramuscular use of fosphenytoin: an overview. 864 11

Fosphenytoin sodium is reviewed, and its safety is compared with that of phenytoin. After i.v. or i.m. injection, fosphenytoin, a phenytoin prodrug, is rapidly hydrolyzed to phenytoin. Free-phenytoin concentrations equivalent to those obtained with i.v. phenytoin can be achieved with fosphenytoin given at equimolar loading doses by selecting the appropriate rate of fosphenytoin administration. Fosphenytoin can be expected to interact with the same drugs that interact with phenytoin. The dosage is expressed as phenytoin sodium equivalents (PE). The standard loading dose for adults with status epilepticus is 15-20 mg PE/kg i.v. infused at 100-150 mg/min; i.m. administration is not recommended for this condition. For nonemergency situations, a 10- to 20-mg PE/kg loading dose can be given i.v. or i.m. Fosphenytoin has advantages over phenytoin injection that are related to its greater aqueous solubility, which obviates the extreme alkalinity, propylene glycol, and ethanol needed in the injectable phenytoin formulation. Intravenous fosphenytoin has been associated with less soft-tissue injury and fewer adverse effects in general than phenytoin. Fosphenytoin, when administered i.m., is completely absorbed, is relatively well tolerated, and provides more predictable serum drug concentrations than i.m. phenytoin. Fosphenytoin offers practical and clinical advantages over i.v. phenytoin.
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PMID:Safety of fosphenytoin sodium. 904 73

Fosphenytoin is a phosphate ester prodrug of phenytoin developed as a replacement for standard injectable sodium phenytoin. After absorption, phenytoin is cleaved (conversion half-life 8-15 min) from fosphenytoin. Unlike phenytoin, fosphenytoin is freely soluble in aqueous solutions (including standard intravenous solutions) and rapidly absorbed by the intramuscular route. Fosphenytoin has been tested successfully for three indications in humans: intramuscular maintenance dosing, intramuscular loading dose administration, and intravenous treatment of status epilepticus. Local toxicity (pain, burning, itching) is less by the intramuscular or intravenous route for fosphenytoin than for standard injectable sodium phenytoin. Systemic toxicity is similar with both preparations except that hypotension is less common and paresthesias are more common with fosphenytoin.
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PMID:Fosphenytoin (Cerebyx). 903 68

Fosphenytoin, a prodrug of phenytoin, is rapidly and completely converted to phenytoin in adults after intravenous or intramuscular administration and is significantly better tolerated than parenteral phenytoin. Fosphenytoin is highly plasma-protein bound and, when present in sufficient concentration, will displace phenytoin from plasma proteins. The clinical utility is that fosphenytoin may be used to achieve therapeutic phenytoin concentrations more rapidly than intravenous phenytoin infused at its maximum recommended rate. In a clinical study of generalized convulsive status epilepticus, fosphenytoin, with or without benzodiazepine pretreatment, controlled seizures in 76 (93.8%) of 81 patients. In other studies, fosphenytoin maintained seizure control when substituted for oral phenytoin and for seizure prophylaxis in neurosurgery and trauma patients. Adverse events associated with fosphenytoin generally were related to the central nervous system and were similar to those associated with phenytoin, except for a higher incidence of transient pruritus with fosphenytoin. Intravenous fosphenytoin has significant advantages over intravenous phenytoin: It requires a shorter infusion time and fewer intravenous disruptions, causes less pain and burning at the infusion site and minimal consequences in case of intravenous infiltration, allows longer maintenance of intravenous sites, and has better intravenous fluid compatibility and stability. In contrast to intramuscular phenytoin, intramuscular fosphenytoin is well tolerated in both large loading doses and maintenance doses.
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PMID:Clinical experience with fosphenytoin in adults: pharmacokinetics, safety, and efficacy. 979 47

Two pharmacoeconomic studies on the treatment of acute seizures have been conducted. In 1991, Kriel and colleagues surveyed parents of children with a history of cluster seizures, prolonged seizures, or status epilepticus who had been instructed in the use of rectal diazepam. A comparison of data before instruction with data after instruction showed a reduced need for emergency department visits with rectal diazepam. Instruction thus provided a pharmacoeconomic benefit, despite the cost of the product. In 1996, Marchetti and coworkers found that intravenous fosphenytoin was associated with fewer adverse events than intravenous phenytoin. Fosphenytoin thus reduced the need for adverse event management and provided a substantial pharmacoeconomic benefit, despite its higher cost, compared with phenytoin. This study had a number of limitations, however, and hospital pharmacists remain resistant to the use of fosphenytoin. Additional studies may provide more pharmacoeconomic data to support the greater use of fosphenytoin in the treatment of acute pediatric seizures.
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PMID:Pharmacoeconomic considerations in treatment options for acute seizures. 979 50

Status epilepticus (SE) treatment should proceed on four fronts: termination of SE, prevention of recurrence, management of potential precipitating causes, and management of SE complications and underlying conditions. The intensity of the treatment should reflect the risk to the patient from SE, and drugs likely to depress respiration and blood pressure should initially be avoided. The Veterans Administration cooperative trial showed that when treating overt SE, first-line treatment success rates were: lorazepam 64.9%; phenobarbital 58.2%; diazepam/phenytoin 55.8%; and phenytoin alone 43.6%. The aggregate response rate to second-line agents for patients who did not respond to first-line agents was 7.0%, and it was 2.3% for third-line agents, raising the question of the efficacy of a second and third drug. The recommended treatment for generalized convulsive SE is to begin with lorazepam. As a second-line agent, phenytoin or fosphenytoin, is still recommended if SE control is not achieved within 5 to 7 min. Fosphenytoin achieves a free phenytoin level of about 2 micro/mL in 15 min, as opposed to 25 min with phenytoin itself. Moreover, fosphenytoin is safer and, despite higher cost, it may be cost-effective. High-dose barbiturates, high-dose benzodiazepines, and propofol are employed for major treatment for refractory SE. Patients at this stage should undergo continuous electroencephalogram monitoring. Once SE is controlled, prevention of seizure recurrence should be individualized to each patient. The major complications of generalized convulsive SE (GCSE), rhabdomyolysis and hyperthermia, should be watched for and treated.
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PMID:Management approaches to prolonged seizures and status epilepticus. 1042 62

If continuous seizure activity lasts longer than 5 minutes generalized tonic-clonic seizures require prompt treatment, if significant morbidity and mortality are to be avoided. The mortality varies (mean: 20%) depending on patient age and etiology. Control of status epilepticus is achieved by benzodiazepines in about 80% of cases: Lorazepam is recommended due to its longer-acting effects on the central nervous system. To maintain the anticonvulsive effect phenytoin is usually administered intravenously. Fosphenytoin (not approved in Germany) has advantages over phenytoin, because it can be given three times more rapidly and produces fewer side effects. The IV use of valproic acid in status epilepticus seems to be promising, but needs further evaluation. There is no generally accepted treatment protocol for the therapy of persistent seizure activity lasting more than 60 minutes (i.e., refractory status epilepticus). Usually phenobarbital, or general anesthesia with thiopental or pentobarbital are treatment recommendations. In recent reports, the administration of midazolam or propofol proved to be effective and well-tolerated.
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PMID:[Therapy of generalized tonic-clonic status epilepticus in adulthood]. 1070 6


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