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)

The anticonvulsant activity of the novel drug D-23129 (N-(2-amino-4-(4-fluorobenzylamino)phenyl)carbamic acid ethyl ester) was evaluated in animal models of epileptic seizures. D-23129 was active after oral and intraperitoneal administration in rats and mice in a range of anticonvulsant tests at nontoxic doses. The compound was active against electrically induced seizures (MES, ED50 rat p.o. = 2.87 mg/kg), against seizures induced chemically by pentylenetetrazole (s.c. PTZ, ED50 mouse p.o. = 13.5 mg/kg), picrotoxin and N-methyl-D-aspartate (NMDA) and in a genetic animal model, the DBA/2 mouse. It was not active against seizures induced by bicuculline and strychnine. Motor impairment, evaluated with the rotarod test and by observation in the open field, was minimal at doses showing anticonvulsant activity. D-23129 was very effective in elevating the threshold for electrically and chemically induced seizures. Considering the dose increasing the MES threshold by 50% (TID50 mouse i.p. = 1.6 mg/kg; TID50 rat i.p. = 0.72 mg/kg) and the TD50 obtained in the rotarod test, the protective index of D-23129 is better than that of valproate and phenytoin. During 14 days chronic oral treatment with 15 mg/kg, no development of tolerance was observed. D-23129 thus presents an orally active, safe, broad spectrum anticonvulsant agent, which is structurally unrelated to anticonvulsants currently used. We expect that D-23129 will improve the treatment of refractory seizures in humans.
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PMID:D-23129: a new anticonvulsant with a broad spectrum activity in animal models of epileptic seizures. 873 24

The novel anticonvulsant drug D-23129 (N-(2-amino-4-(4-fluorobenzylamino)-phenyl) carbamic acid ethyl ester) was evaluated in the amygdala kindling model of complex partial seizures in rats. D-23129 exerts potent anticonvulsant activity against both focal and generalized seizures in animal models of epilepsy. After intraperitoneal and oral administration in kindled rats, the substance dose dependently increased the threshold for induction of afterdischarges, exerting significant effects already after 0.01 mg/kg. In higher doses (2.5-5 mg/kg i.p., 10-15 mg/kg p.o.) D-23129 also exerted anticonvulsant effects on other seizure parameters of amygdala-kindled rats, i.e. seizure severity, seizure duration, total duration of behavioural changes and afterdischarge duration. The adverse effects of D-23129 were quantitated in the open field and in the rotarod test, a standard test for motor impairment. D-23129 exerted no adverse effects on behaviour in doses up to 5 mg/kg i.p. and 15 mg/kg p.o. Comparing the adverse effects between kindled and non-kindled rats, no differences were found. The data demonstrate that D-23129 is more potent in the amygdala kindling model of complex partial seizures than in other seizure models. D-23129 is orally active and is devoid of neurotoxic effects in anticonvulsant doses, thus indicating that this compound has potential for antiepileptic therapy.
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PMID:D-23129: a potent anticonvulsant in the amygdala kindling model of complex partial seizures. 881 62

The purpose of this study was to evaluate the effects of the new anticonvulsant drug N-(2-amino-4-[fluorobenzylaminol-phenyl) carbamic acid ethyl ester (retigabine, D-23129, ASTA Medica, Dresden, Germany) on different patterns of epileptiform activity induced by 4-aminopyridine (4AP) in rat entorhinal cortex hippocampal slices. Application of 4AP (100 microM) induced in entorhinal cortex two different types of epileptiform activities; seizure-like events (SLE) and interictal epileptiform discharges (IED). Bicuculline (10 microM) changed 4AP-induced SLE and IED to recurrent epileptiform discharges (RED). IED were isolated after blockade of the SLE by glutamate receptor antagonists for alpha-amino-3-hydroxy-5-methylisoxazole4-proprionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors, i.e. 1,2,3,4 tetrahydro-6-nitro-2,3-dioxo-benzolflquinoxaline-7-sulfonamide (NBQX, 10 microM) and 2-amino-5-phosphonovaleric acid (APV, 30 microM). Anticonvulsant properties of retigabine were evaluated as effect on the frequency and amplitude of SLE, IED and RED. Retigabine suppressed all types of epileptiform events in a dose dependent and reversible manner. SLE were suppressed in 71.4 and 100% of slices by 5 and 10 microM, respectively. The frequency of IED was significantly reduced by 20 microM retigabine (40.9+/-24.5%) and IED were blocked completely by 50 microM retigabine. When IED were isolated by application of glutamate antagonists 20 microM retigabine was sufficient to block this activity completely. RED induced by combined application of bicuculline and 4AP were blocked in 71.4% of the tested slices with 100 microM retigabine. The frequency of the RED in the remaining slices was reduced by 96.1+/-6.1%. We conclude that retigabine acts on a large variety of different epileptiform activities in temporal lobe structures that are known to develop readily pharmacoresistant seizures.
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PMID:Effects of retigabine (D-23129) on different patterns of epileptiform activity induced by 4-aminopyridine in rat entorhinal cortex hippocampal slices. 993 48

Retigabine [N-(2-amino-4-[fluorobenzylamino]-phenyl) carbamic acid; D-23129] is a novel anticonvulsant, unrelated to currently available antiepileptic agents, with activity in a broad range of seizure models. In the present study, we sought to determine whether retigabine could enhance current through M-like currents in PC12 cells and KCNQ2/Q3 K(+) channels expressed in Chinese hamster ovary cells (CHO-KCNQ2/Q3). In differentiated PC12 cells, retigabine enhanced a linopirdine-sensitive current. The effect of retigabine was associated with a slowing of M-like tail current deactivation in these cells. Retigabine (0.1 to 10 microM) induced a potassium current and hyperpolarized CHO cells expressing KCNQ2/Q3 cells but not in wild-type cells. Retigabine-induced currents in CHO-KCNQ2/Q3 cells were inhibited by 60.6 +/- 11% (n = 4) by the KCNQ2/Q3 blocker, linopirdine (10 microM), and 82.7 +/- 5.4% (n = 4) by BaCl(2) (10 mM). The mechanism by which retigabine enhanced KCNQ2/Q3 currents involved large, drug-induced, leftward shifts in the voltage dependence of channel activation (-33.1 +/- 2.6 mV, n = 4, by 10 microM retigabine). Retigabine shifted the voltage dependence of channel activation with an EC(50) value of 1.6 +/- 0.3 microM (slope factor was 1.2 +/- 0.1, n = 4 to 5 cells per concentration). Retigabine (0.1 to 10 microM) also slowed the rate of channel deactivation, predominantly by increasing the contribution of a slowly deactivating tail current component. Our findings identify KCNQ2/Q3 channels as a molecular target for retigabine and suggest that activation of KCNQ2/Q3 channels may be responsible for at least some of the anticonvulsant activity of this agent.
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PMID:Retigabine, a novel anti-convulsant, enhances activation of KCNQ2/Q3 potassium channels. 1095 53

Retigabine (D-2319, 0.5-20 mg/kg i.p.) antagonised dose dependently audiogenic seizures in DBA/2 mice. Retigabine at 0.5 mg/kg i.p., a dose that per se did not affect the occurrence of audiogenic seizures significantly, potentiated the anticonvulsant activity of carbamazepine, diazepam, felbamate, lamotrigine, phenytoin, phenobarbital and valproate against sound-induced seizures in DBA/2 mice. The degree of additivity for the effect induced by retigabine was greatest for diazepam, phenobarbital, phenytoin and valproate, less for carbamazepine and lamotrigine and least for felbamate. The increase in anticonvulsant activity was usually associated with a comparable increase in motor impairment. However, the therapeutic index of combined treatment (drugs plus retigabine), was more favourable than the same drug plus vehicle. Since retigabine had no significant influence on the total and free plasma levels of the anticonvulsant drugs, pharmacokinetic interactions, in terms of total or free plasma levels, are not probable. However, the possibility that retigabine modifies the clearance of the anticonvulsant drugs from the brain cannot be excluded. Retigabine had no significant effect on the hypothermic effects of the anticonvulsants tested. In conclusion, retigabine showed an additive effect when administered in combination with classical anticonvulsants, most notably diazepam, phenobarbital, phenytoin and valproate.
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PMID:Influence of retigabine on the anticonvulsant activity of some antiepileptic drugs against audiogenic seizures in DBA/2 mice. 1128 48

The antiepileptic effects of the novel antiepileptic drug retigabine (D-23129) [N-(2-amino-4-(4-flurobenzylamino)phenyl) carbamid acid ethyl ester] were tested in neocortical slice preparations (n=23) from 17 patients (age, 3-42 years) who underwent surgery for the treatment of intractable epilepsy. Epileptiform events consisted of spontaneously occurring rhythmic sharp waves, as well as of epileptiform field potentials (EFP) elicited by superfusion with Mg(2+)-free solution without or with addition of 10 micromol/l bicuculline. (1) Spontaneous rhythmic sharp waves (n=6), with retigabine application, the repetition rate was decreased down to 12-47% of initial value (10 micromol/l, n=3) after 180 min or suppressed completely within 12 min (50 micromol/l, n=3). (2) Low Mg(2+) EFP (n=9), with retigabine application, the repetition rate was decreased down to 50 and 65% of initial value (10 micromol/l; n=2) after 180 min or suppressed completely after 9-55 min (10, 50 and 100 micromol/l; n=2 in each case). In one slice only a transient reduction of the repetition rate was seen with 10 micromol/l retigabine. (3) Low Mg(2+) EFP with addition of bicuculline (n=8), with retigabine application, the repetition rate was decreased down to 12-55% of initial value (10 micromol/l; n=4) after 180 min or suppressed completely after 6-30 min (50 and 100 micromol/l; n=2 in each case). The depressive effect of retigabine was reversible in all but one slice. The results show a clear antiepileptic effect of retigabine in human neocortical slices on spontaneously occurring rhythmic sharp waves and different types of induced seizure activity.
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PMID:Effects of retigabine on rhythmic synchronous activity of human neocortical slices. 1132 71

The Sixth Eilat Conference on New Antiepileptic Drugs (AEDs) took place in Taormina, Sicily, Italy from 7th to 11th April, 2002. Basic scientists, clinical pharmacologists and neurologists from 27 countries attended the conference, whose main themes included dose-response relationships with conventional and recent AEDs, teratogenic effects of conventional and recent AEDs, update on clinical implications of AED metabolism, prevention of epileptogesis, and seizure aggravation by AEDs. According to tradition, the central part of the conference was devoted to a review of AEDs in development, as well to updates on AEDs, which have been marketed in recent years. This article summarizes the information presented on drugs in preclinical and clinical development, including carabersat (SB-204269), CGX-1007 (Conantokin-G), pregabalin, retigabine (D-23129), safinamide, SPD421 (DP-VPA), SPM 927, talampanel and valrocemide (TV 1901). Updates on fosphenytoin, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin, zonisamide, new formulations of valproic acid, and the antiepileptic vagal stimulator device are also presented.
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PMID:Progress report on new antiepileptic drugs: a summary of the Sixth Eilat Conference (EILAT VI). 1235 Mar 82

Retigabine [D23129; N-(2-amino-4-(4-fluorobenzylamino)-phenyl)carbamic acid ethyl ester] is an antiepileptic drug with a recently described novel mechanism of action that involves opening of neuronal K(V)7.2-7.5 (formerly KCNQ2-5) voltage-activated K(+) channels. These channels (primarily K(V)7.2/7.3) enable generation of the M-current, a subthreshold K(+) current that serves to stabilize the membrane potential and control neuronal excitability. In this regard, retigabine has been shown to have a broad-spectrum of activity in animal models of electrically-induced (amygdala-kindling, maximal electroshock) and chemically-induced (pentylenetetrazole, picrotoxin, NMDA) epileptic seizures. These encouraging results suggest that retigabine may also prove useful in the treatment of other diseases associated with neuronal hyperexcitability. Neuropathic pain conditions are characterized by pathological changes in sensory pathways, which favor action potential generation and enhanced pain transmission. Although sometimes difficult to treat with conventional analgesics, antiepileptics can relieve some symptoms of neuropathic pain. A number of recent studies have reported that retigabine can relieve pain-like behaviors (hyperalgesia and allodynia) in animal models of neuropathic pain. Neuronal activation within several key structures within the CNS can also be observed in various animal models of anxiety. Moreover, amygdala-kindled rats, which have a lowered threshold for neuronal activation, also display enhanced anxiety-like responses. Retigabine dose-dependently reduces unconditioned anxiety-like behaviors when assessed in the mouse marble burying test and zero maze. Early clinical studies have indicated that retigabine is rapidly absorbed and distributed, and is resistant to first pass metabolism. Tolerability is good in humans when titrated up to its therapeutic dose range (600-1200 mg/day). No tolerance, dependence or withdrawal potential has been reported, although adverse effects can include mild dizziness, headache, nausea and somnolence. Thus, retigabine may prove to be useful in the treatment of a diverse range of disease states in which neuronal hyperexcitability is a common underlying factor.
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PMID:Retigabine: chemical synthesis to clinical application. 1586 50

ASTA Medica is developing retigabine, a carbamic acid ethyl ester and a selective potassium channel opener, for the treatment of complex partial seizures. Phase II trials have commenced [249117], and a multicenter placebo-controlled dosage-finding study has begun in Europe and Australia [392702]. Retigabine is also undergoing phase II testing in Germany, Switzerland, Russia and the US for the potential treatment of epilepsy [323383]. Phase II trials have shown >50% reduction in seizure frequency in 12 of 35 patients with refractory epilepsy [373379]. Phase I clinical trials for epilepsy were successfully completed in Germany in 1995 [180371]. Single and multiple dose trials demonstrated the tolerability and favorable pharmacokinetic behavior of the compound [264306]. The compound showed good compatibility and exhibits an antisense anticonvulsive effect in various preclinical epilepsy models [250565,299344]. Side effects of mild to moderate tiredness, fatigue and nausea were observed [276123]. The spectrum of activity of retigabine resembles that of valproate, but its potency is greater and toxicity is reduced [373379]. The mechanism of action of retigabine is probably multifactorial. Research has shown that retigabine acts as a selective K+ channel opener in neuronal cells and this can be expected to contribute to its anticonvulsant effect [273670]. In addition it demonstrates potentiation of GABA transmission and possibly also weak modulation of sodium and calcium channels [299344]. Retigabine also has neuroprotective activity with potential for the treatment of stroke and neurodegenerative diseases, such as Alzheimer's disease, Huntington's disease and multiple sclerosis [249381]. In February 2000, Lehman Brothers predicted product launch could be as early as 2002 for epilepsy in the US [357788]. In February 1999, Lehman Brothers predicted that the first major launch date of the drug would be 2003, and the year of peak sales to be 2011 [319225].
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PMID:Retigabine (ASTA Medica). 1603 7

Retigabine has anticonvulsant properties that appear to be primarily mediated by opening neuronal voltage-gated potassium channels. This action has been shown in neuronal KCNQ2/3 and KCNQ3/5 potassium channels. In addition to this unique action, retigabine also potentiates GABA-evoked currents in cortical neurons at high concentrations. When used as adjunctive therapy in patients with partial seizures, retigabine 600-1200 mg/day (200-400 mg three times daily) was associated with significant linear dose-dependent reductions in monthly seizure frequency compared with placebo in a large 16-week randomised phase II trial. Median monthly seizure frequency decreased from baseline by up to 35% among patients in the retigabine treatment arms compared with 13% in the placebo group. Retigabine 1200 mg/day was also significantly more effective than retigabine 600 mg/day. Responder rates, defined as the proportion of patients with > or = 50% reduction in seizure frequency, were significantly higher among patients in the retigabine 900 and 1200 mg/day groups than in those who received placebo. CNS-related adverse events were the most commonly reported treatment-emergent adverse events associated with retigabine in clinical trials. Across all three retigabine groups in the large phase II trial, somnolence (20.3%), dizziness (14.6%), confusion (12.3%) and speech disorder (11.3%) were the most frequent CNS-related adverse events.
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PMID:Retigabine: in partial seizures. 1680 Jul 18


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