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)

Epilepsy is a common comorbidity among developmentally disabled (DD) patients, and special considerations apply to its treatment. In particular, clinicians should try to avoid antiepileptic drugs (AEDs) with sedating properties or adverse cognitive effects that might further diminish quality of life for DD patients. Behavioral changes due to medication and significant pharmacokinetic interactions with other medications are also concerns. The newer AEDs, approved in the 1990s, offer new options for the treatment of individuals with developmental disability and epilepsy. Gabapentin does not interact with the hepatic metabolism of other AEDs or psychotropic agents, results in a statistically significant reduction in seizure frequency in mentally retarded children, and is generally well tolerated. Felbamate is an effective broad-spectrum AED, but has serious toxicity issues limiting its use. Lamotrigine has been extensively studied in the DD population, achieving seizure reduction rates of up to 50% in some trials. Although it is usually well tolerated in this population, its pharmacokinetic profile is influenced by concomitant medications. Levetiracetam has been found to be effective against kindled seizures and has been approved as adjunctive therapy for partial epilepsies. It does not cause any pharmacokinetic interactions, but may have behavioral side effects. Oxcarbazepine is a homologue of carbamazepine that has fewer drug interactions. It is approved for mono- or adjunctive therapy in patients with partial seizures, and its use in DD individuals appears to be worthwhile. Tiagabine is extensively bound to plasma proteins and is therefore subject to protein-binding displacement interactions by other highly protein-bound drugs, such as sodium valproate. While there are trial data showing its efficacy as adjunctive therapy in partial epilepsy in adults and children, there is a paucity of data specific to the DD population. Common side effects include sedation. Topiramate is a broad-spectrum AED approved as adjunctive therapy for partial and primary generalized tonic-clonic seizures. It appears to be particularly effective in patients with Lennox-Gastaut syndrome and those with cognitive disabilities. It appears to be better tolerated in the DD population than in the general population. Zonisamide has been effective in the DD population, yielding a seizure reduction of 50% in 41% of children in 1 trial. It has been associated with renal stone formation, sedation, and cognitive effects, however. The new AEDs have a role in treating seizures in the DD. Side effects that limit their use include anorexia, behavioral changes, and sedation. Seizure exacerbation can occur with the new AEDs and success is defined empirically and by improvements in quality of life.
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PMID:Antiepileptic drug treatment in the developmentally disabled: treatment considerations with the newer antiepileptic drugs. 1260 9

Zonisamide is an antiepileptic drug developed and first marketed in Japan in 1989. Cases of oligohydrosis, characterized by deficient production and secretion of sweat, were reported in children treated with zonisamide in Japan during development and in the postmarketing period. Zonisamide was approved in the United States in March 2000 for adjunctive treatment of partial seizures in adults. Searching the Food and Drug Administration's Adverse Events Reporting System, we identified six domestic cases of zonisamide-associated oligohydrosis and/or fever, all in patients </= 18 years of age. The calculated reporting rate was 13 cases per 10,000 pediatric-years of exposure, approximately 10-fold the reporting rate in Japan. A possible risk factor for the development of oligohydrosis in these cases was pediatric age, leading to exposure to elevated zonisamide blood levels relative to patient size. Although the mechanism for zonisamide-associated oligohydrosis has not been fully elucidated, the drug may mediate its effect on eccrine sweat glands by inhibiting carbonic anhydrase, thereby influencing pH dynamics, hydrogen ion concentration, and available calcium transients. Awareness of zonisamide-associated oligohydrosis may prevent morbidity, especially in the pediatric population.
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PMID:Oligohydrosis and fever in pediatric patients treated with zonisamide. 1277 Jun 70

We report a case of adversive seizures featuring neck rotation and conjugate deviation induced by the hyperventilation maneuver. At the age of 6 years the patient suffered from conjugate deviation to the left. She herself felt no symptoms other than oculomotor symptoms. Hyperventilation induced an adversive seizure and ictal EEG showed sharp waves in the right frontal, central, and parietal areas. No brain image showed abnormal findings. Zonisamide completely attenuated her attacks. It is well known that hyperventilation induces absence seizures, and it has been reported that hyperventilation can induce complex partial seizures. However, no previous reports have described patients diagnosed as having adversive seizures with conjugate deviation induced by hyperventilation. We report the present case because, although its epileptogenesis is unknown, the patient is a rare case not only clinically but also electrophysiologically.
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PMID:A case of adversive seizures induced by hyperventilation. 1292 16

Although the significant progress in pharmacotherapy of epilepsy during last decade was achieved, about one third of patients are resistant to the current treatment. When the monotherapy is not efficient, the polytherapy should be applied. Zonisamide (ZNS) is a new antiepileptic drug (AED) efficient in treating refractory epilepsy. Its efficacy in different types of seizures was confirmed in various animal studies as well as in clinical conditions. ZNS inhibits voltage-dependent Na(+) channels and Ca(2+) channels of T-type. The drug influences also monoamine neurotransmission and exhibits free radical scavenging properties. ZNS has a linear and favorable pharmacokinetics with excellent oral bioavailability. Furthermore, ZNS treatment, compared to other anticonvulsants, is relatively safe and well tolerated. Since ZNS is often used in polytherapy, its interactions with other AEDs seem to be of particular importance. However, the experimental data are rather inconsistent and further studies are necessary to elucidate exact effects of coadministration of ZNS with other AEDs. Recently, the clinical and experimental studies have suggested some new indications for ZNS administration, as mania, neuropathic pain, Parkinson's disease or migraine prophylaxis. Nowadays, it is also well established that ZNS exerts neuroprotective properties.
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PMID:Zonisamide: a new antiepileptic drug. 1470 63

The risk of epileptic seizures after craniotomy is extremely important but the incidence of postoperative epilepsy varies greatly, depending on the patient's conditions such as primary diseases, severity of surgical insult, and pre-existing epilepsy. Animal studies suggest that neurosurgical insults lead to seizures by two different mechanisms: One mechanism is mediated by free radical generation and the other by impaired ion balance across the cell membrane caused by ischemia or hypoxia. Conventional antiepileptic agents such as phenytoin, phenobarbital, carbamazepine, and valproic acid are promising for the prevention of early seizures, but the effect in preventing postoperative epilepsy is still controversial. Studies on the prophylactic effect of newer antiepileptic agents in craniotomized patients were very limited. Zonisamide, an antiepileptic agent with antiepileptogenic, free radical scavenging and neuroprotective actions in experimental animals, showed promising effects against postoperative epilepsy in a randomized double blind controlled trial. Prophylactic treatment for craniotomized patients significantly prevented the development of partial seizures during the follow-up period. Most recent studies have not supported the prophylactic use of antiepileptic agents in craniotomized patients, but further studies are required.
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PMID:Postoperative seizures: epidemiology, pathology, and prophylaxis. 1472 65

Zonisamide is a new type of benzisoxazole derivative, first marketed in Japan in 1989. This study analyzed: (1) the drug's efficacy by seizure and epilepsy type in a total of 1008 patients treated during the development of zonisamide in Japan; (2) the effectiveness of zonisamide for 726 newly-diagnosed patients treated with zonisamide postmarketing; and (3) 50 patients with generalized epilepsies and epileptic syndromes (idiopathic generalized epilepsies, symptomatic generalized epilepsies, Lennox-Gastaut syndrome, Doose syndrome, and West syndrome), and 19 patients with undetermined epilepsies and specific syndromes (refractory grand mal in childhood, severe myoclonic epilepsy in infancy, other undetermined epilepsy, familial essential myoclonic epilepsy, and mitochondrial encephalomyopathy with ragged-red fibers). Analysis of study results showed that among all patients treated, zonisamide was highly effective for the treatment of idiopathic generalized epilepsy, temporal lobe epilepsy, and other partial epilepsies. The compound was also effective for other symptomatic generalized epilepsies. In 50 patients with generalized epilepsies, and 19 with undetermined epilepsies and specific syndromes, seizure frequency was reduced by >50% with monotherapy or two-drug therapy with zonisamide. Zonisamide was effective not only for partial epilepsies and generalized epilepsies but also for undetermined epilepsies and specific syndromes such as myoclonus epilepsy.
Seizure 2004 Dec
PMID:Overview of Japanese experience-controlled and uncontrolled trials. 1551 80

Zonisamide is a benzisoxazole-based compound first synthesized in the early 1970s by the research laboratories of Dainippon Pharmaceutical Company in Osaka, Japan. Identified as an anticonvulsant during exploratory research, zonisamide has since been characterized as having broad-spectrum antiepilepsy and neuroprotective effects. Early clinical studies in Japan demonstrated that zonisamide has a long elimination half-life and is well tolerated; Phase II and III clinical trials established the drug's efficacy and safety for the treatment of partial and generalized seizures. In 1989, zonisamide was approved and marketed in Japan under the trade name of Excegran. Data from postmarketing surveillance studies and clinical observations over 10 years of use have continued to support zonisamide's efficacy and safety, identified its usefulness as monotherapy, and characterized its effectiveness for various seizure types and epilepsy syndromes.
Seizure 2004 Dec
PMID:Review of zonisamide development in Japan. 1551 83

This study examined the efficacy and safety of zonisamide as monotherapy in pediatric patients with epilepsy. Seventy-seven children with epilepsy (ages 8 months-15 years) were treated with zonisamide. Nine patients were withdrawn early because of side effects; these patients were included in side effect but not efficacy analyses. Zonisamide dosages were initiated at approximately 2 mg/kg per day and adjusted for each patient individually to a maximum of 12 mg/kg per day. Among 44 patients with cryptogenic/symptomatic partial epilepsy, 36 (82%) became seizure free; 4 (9%) had a > or =50% reduction in seizure frequency; and 4 (9%) had no change in seizures with zonisamide treatment. Of 11 patients with cryptogenic/symptomatic generalized epilepsy, 10 (91%) became seizure free, and 1 experienced no change with zonisamide treatment. Similarly, 4 patients (100%) with idiopathic partial epilepsy, and 8 of 9 patients (89%) with idiopathic generalized epilepsy became seizure free with zonisamide treatment; in the last group, 1 experienced no change. Thirty patients (39%) reported side effects, including somnolence (11.7%), decreased spontaneity (7.8%), anorexia (6.5%), and rash (6.5%). Thus, zonisamide is effective for partial seizures with or without secondarily generalized seizures in children and should be considered a broad-spectrum antiepilepsy agent.
Seizure 2004 Dec
PMID:Effects of zonisamide monotherapy in children with epilepsy. 1551 85

The current overview of zonisamide use and effectiveness is based on both a long-term prospective postmarketing survey and current zonisamide use at the Saitama Medical College, Department of Neuropsychiatry. Survey data, which were collected from individual physicians and 23 survey groups throughout Japan, assessed the effectiveness of zonisamide in 1631 patients. Zonisamide was highly effective for treating partial seizures, with 70% of patients reporting improvement. More than half of patients with generalized seizures (58%) and half of patients with myoclonic and atypical absence seizures showed improvement with zonisamide treatment. Among the different epileptic syndromes, zonisamide was highly effective in treating generalized idiopathic epilepsy (> or =78% improvement) and partial epilepsy (> or =58% improvement). However, only 28% of patients with West syndrome or Lennox-Gastaut syndrome showed improvement. Among 60 outpatients treated with zonisamide at our facility as of October 1998, most had partial seizures or generalized seizures subsequent to partial seizures. The majority of patients received zonisamide in combination with other antiepilepsy drugs. Patients receiving zonisamide monotherapy showed greater improvement than did patients receiving polytherapy. We conclude that zonisamide is highly effective for partial seizures and generalized seizures, and that there appears to be no decrease in efficacy with long-term use.
Seizure 2004 Dec
PMID:Efficacy of zonisamide: our experience. 1551 89

Zonisamide is a synthetic 1,2-benzisoxazole-3-methanesulfonamide with anticonvulsant properties. The sulfamoyl group on zonisamide was expected to suppress seizures in a manner similar to another sulfonamide analogue, acetazolamide, through inhibition of carbonic anhydrase. However, this does not appear to be the primary mechanism of action since zonisamide requires much higher doses than acetazolamide to achieve equivalent titration in vivo. Studies with cultured neurons indicate that zonisamide blocks repetitive firing of voltage-sensitive sodium channels and reduces voltage-sensitive T-type calcium currents without affecting L-type calcium currents. Its dual mechanism of action may explain its efficacy in patients resistant to other antiepileptic drugs (AEDs). Zonisamide has a pharmacokinetic profile favorable for clinical use. It is rapidly and completely absorbed and has a long half-life (63-69h in healthy volunteers) which allows twice-daily, or even once-daily, dosing. Zonisamide is not highly bound to plasma proteins. Consequently, it does not affect protein binding of other highly protein-bound AEDs. Furthermore, zonisamide does not induce its own metabolism and does not induce liver enzymes. However, since zonisamide is metabolized by cytochrome P450, liver enzyme-inducing AEDs will increase zonisamide clearance, and dosage adjustments may be necessary when it is used in combination with certain AEDs.
Seizure 2004 Dec
PMID:Zonisamide: chemistry, mechanism of action, and pharmacokinetics. 1551 91


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