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Drug Design, Development and Therapy 2017Currently, a number of novel anticonvulsant drugs, the so-called third generation, are in various stages of development. Several of them are already available or in... (Review)
Review
Currently, a number of novel anticonvulsant drugs, the so-called third generation, are in various stages of development. Several of them are already available or in ongoing clinical trials. These new compounds should take advantage of new insights into the basic pathophysiology of epileptogenesis, drug metabolism and drug interactions. Many of them still need to be further evaluated mainly in real-world observational trials and registries. Among newer anticonvulsant drugs for partial-onset seizures (POSs), rufinamide, lacosamide, eslicarbazepine and perampanel are those new treatment options for which more substantial clinical evidence is currently available, both in adults and, to some extent, in children. Among the newest anticonvulsant drugs, brivaracetam, a high-affinity synaptic vesicle protein 2A ligand, reported to be 10- to 30-fold more potent than levetiracetam, is highly effective in a broad range of experimental models of focal and generalized seizures. Unlike levetiracetam, brivaracetam does not inhibit high-voltage Ca channels and AMPA receptors and appears to inhibit neuronal voltage-gated sodium channels playing a role as a partial antagonist. Brivaracetam has a linear pharmacokinetic profile, is extensively metabolized and is excreted by urine (only 8%-11% unchanged). It does not seem to influence the pharmacokinetics of other antiepileptic drugs. It was approved in the European Union in January 2016 and in the US in February 2016 as an adjunctive therapy for the treatment of POS in patients older than 16 years of age. To date, its clinical efficacy as adjunctive antiepileptic treatment in adults with refractory POS at doses between 50 and 200 mg daily has been extensively assessed in two Phase IIb and four Phase III randomized controlled studies. Long-term extension studies show sustained efficacy of brivaracetam. Overall, the drug is generally well tolerated with only mild-to-moderate side effects. This is true also by intravenous route. Brivaracetam has not yet been evaluated as monotherapy or in comparison with other new anticonvulsant drugs.
Topics: Anticonvulsants; Epilepsies, Partial; Humans; Pyrrolidinones
PubMed: 28293101
DOI: 10.2147/DDDT.S103468 -
The Journal of Pharmacology and... Apr 2023To provide back-up compounds to support the development of the GABA receptor (GABAAR) potentiator KRM-II-81, three novel analogs were designed: replacing the pyridinyl...
To provide back-up compounds to support the development of the GABA receptor (GABAAR) potentiator KRM-II-81, three novel analogs were designed: replacing the pyridinyl with 2'-Cl-phenyl (FR-II-60), changing the positions of the N and O atoms in the oxazole ring with addition of an ethyl group (KPP-III-34 and KPP-III-51), or substituting a Br atom for the ethynyl of KRM-II-81 (KPP-III-34). The compounds bound to brain GABAARs. Intraperitoneal administration of FR-II-60 and KPP-III-34 produced anticonvulsant activity in mice [maximal electroshock (MES)-induced seizures or 6 Hz-induced seizures], whereas KPP-III-51 did not. Although all compounds were orally bioavailable, structural changes reduced the plasma and brain (FR-II-60 and KPP-III-51) exposures relative to KRM-II-81. Oral administration of each compound produced dose-dependent increases in the latency for both clonic and tonic seizures and the lethality induced by pentylenetetrazol (PTZ) in mice. Since KPP-III-34 produced the highest brain area under the curve (AUC) exposures, it was selected for further profiling. Oral administration of KPP-III-34 suppressed seizures in corneal-kindled mice, hippocampal paroxysmal discharges in mesial temporal lobe epileptic mice, and PTZ-induced convulsions in rats. Only transient sensorimotor impairment was observed in mice, and doses of KPP-III-34 up to 500 mg/kg did not produce impairment in rats. Molecular docking studies demonstrated that all compounds displayed a reduced propensity for binding to 1His102 compared with the sedating compound alprazolam; the bromine-substituted KPP-III-34 achieved the least interaction. Overall, these findings document the oral bioavailability and anticonvulsant efficacy of three novel analogs of KRM-II-81 with reduced sedative effects. SIGNIFICANCE STATEMENT: A new non-sedating compound, KRM-II-81, with reduced propensity for tolerance is moving into clinical development. Three new analogs were orally bioavailable, produced anticonvulsant effects in rodents, and displayed low sensorimotor impairment. KPP-III-34 demonstrated efficacy in models of pharmacoresistant epilepsy. Docking studies demonstrated a low propensity for compound binding to the α1His102 residue implicated in sedation. Thus, three additional structures have been added to the list of non-sedating imidazodiazepine anticonvulsants that could serve as backups in the clinical development of KRM-II-81.
Topics: Rats; Mice; Animals; Anticonvulsants; Molecular Docking Simulation; Seizures; Oxazoles; Epilepsy; Receptors, GABA-A; Pentylenetetrazole; Electroshock
PubMed: 36746611
DOI: 10.1124/jpet.122.001362 -
Pharmacological Reports : PR 2006Antiepileptic drugs (AEDs) affect various neurotransmitters (i.e. GABA, glutamate), receptors (i.e. GABAergic, glutamatergic), and ion channels (i.e. for sodium or... (Review)
Review
Antiepileptic drugs (AEDs) affect various neurotransmitters (i.e. GABA, glutamate), receptors (i.e. GABAergic, glutamatergic), and ion channels (i.e. for sodium or calcium) which is responsible for their anticonvulsant activity. However, this broad spectrum of action may be also utilized in other pathological conditions. For example, both conventional and newer AEDs may be used in patients suffering from neuropathic pain, migraine, essential tremor, spasticity, restless legs syndrome and a number of psychiatric disorders (f.e. bipolar disease or schizophrenia). Also, isolated data point to their potential use in Parkinson's or Alzheimer's disease. There is experimental background indicating a potent neuroprotective efficacy of AEDs in numerous models of brain ischemia. However, the clinical data are very limited and this problem requires careful assessment.
Topics: Animals; Anticonvulsants; Humans; Mental Disorders; Neuroprotective Agents
PubMed: 16531624
DOI: No ID Found -
Polish Journal of Pharmacology 2004Valproic acid (VPA) is one of four first-line antiepileptic drugs (AEDs) currently established in the long-term treatment of epilepsy. Despite VPA's wide spectrum of... (Review)
Review
Valproic acid (VPA) is one of four first-line antiepileptic drugs (AEDs) currently established in the long-term treatment of epilepsy. Despite VPA's wide spectrum of action, in some cases its use is limited due to specific pharmacokinetics and dangerous adverse effects. These include hepatotoxicity and teratogenecity. Such limitations account for intensive research that has been carried out in order to develop new analogues or derivatives of VPA. In our review, we focus on three out of a number of substances that have been lately under investigation: NPS 1776, valrocemide and DP-VPA. These potential AEDs present both good anticonvulsive and safety profiles and seem to be more potent than the original VPA. Clinical trials, which are now ongoing, will answer the question whether or not they could become second generation of VPA.
Topics: Animals; Anticonvulsants; Clinical Trials as Topic; Epilepsy; Glycine; Half-Life; Humans; Valproic Acid
PubMed: 15215557
DOI: No ID Found -
Molecules (Basel, Switzerland) Jan 2017Some novel fluorinated quinazolines (-) were designed and synthesized to be evaluated for their anticonvulsant activity and their neurotoxicity. Structures of all newly...
Some novel fluorinated quinazolines (-) were designed and synthesized to be evaluated for their anticonvulsant activity and their neurotoxicity. Structures of all newly synthesized compounds were confirmed by their infrared (IR), mass spectrometry (MS) spectra, ¹H nuclear magnetic resonance (NMR), C-NMR, and elemental analysis (CHN). The anticonvulsant activity was evaluated by a subcutaneous pentylenetetrazole (scPTZ) test and maximal electroshock (MES)-induced seizure test, while neurotoxicity was evaluated by a rotorod test. The molecular docking was performed for all newly-synthesized compounds to assess their binding affinities to the GABA-A receptor in order to rationalize their anticonvulsant activities in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticonvulsant activity for all newly-synthesized compounds. Compounds , , and showed the highest binding affinities toward the GABA-A receptor, along with the highest anticonvulsant activities in experimental mice. These compounds also showed low neurotoxicity and low toxicity in the median lethal dose test compared to the reference drugs. A GABA enzymatic assay was performed for these highly active compounds to confirm the obtained results and explain the possible mechanism for anticonvulsant action. The most active compounds might be used as leads for future modification and optimization.
Topics: Animals; Anticonvulsants; Drug Design; Hydrophobic and Hydrophilic Interactions; Mice; Models, Molecular; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Protein Binding; Quinazolines; Receptors, GABA-A; Structure-Activity Relationship
PubMed: 28125041
DOI: 10.3390/molecules22020188 -
Epilepsia Jun 2015This review summarizes the therapeutic potential of midazolam as an anticonvulsant antidote for organophosphate (OP) intoxication. (Review)
Review
OBJECTIVE
This review summarizes the therapeutic potential of midazolam as an anticonvulsant antidote for organophosphate (OP) intoxication.
METHODS
Benzodiazepines are widely used to treat acute seizures and status epilepticus (SE), a neurologic emergency of persistent seizures that can lead to severe neuronal damage or death. Midazolam is a benzodiazepine hypnotic with a rapid onset and short duration of action.
RESULTS
Midazolam is considered the new drug of choice for persistent acute seizures and SE, including those caused by neurotoxic OPs and nerve agents. Midazolam is a positive allosteric modulator of synaptic γ-aminobutyric acid (GABA)A receptors in the brain. It potentiates GABAergic inhibition and thereby controls hyperexcitability and seizures. Midazolam is administered intravenously or intramuscularly to control acute seizures and SE. Due to its favorable pharmacokinetic features, midazolam is being considered as a replacement anticonvulsant for diazepam in the antidote kit for nerve agents. Clinical studies such as the recent Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) trial have confirmed the anticonvulsant efficacy of midazolam in SE in prehospital settings.
SIGNIFICANCE
In experimental models, midazolam is effective when given at the onset of seizures caused by nerve agents. However, benzodiazepines are less effective at terminating seizures when given 30 min or later after OP exposure or seizure onset, likely because of internalization or downregulation of synaptic, but not extrasynaptic, GABAA receptors, which can lead to diminished potency and seizure recurrence.
Topics: Animals; Anticonvulsants; Epilepsy; Humans; Midazolam; Organophosphate Poisoning
PubMed: 26032507
DOI: 10.1111/epi.12989 -
Chemical & Pharmaceutical Bulletin Mar 2010A series of 7-alkoxy-2H-1,4-benzothiazin-3(4H)-ones and a new series of 7-alkoxy-4H-[1,2,4]triazolo[4,3-d]benzo[b][1,4]thiazine derivatives were synthesized using...
A series of 7-alkoxy-2H-1,4-benzothiazin-3(4H)-ones and a new series of 7-alkoxy-4H-[1,2,4]triazolo[4,3-d]benzo[b][1,4]thiazine derivatives were synthesized using 5-methoxybenzo[d]thiazol-2-amine as starting material. The structures of the compounds were elucidated by IR, (1)H-NMR spectroscopic data and microanalyses. The anticonvulsant activity of these compounds was evaluated by maximal electroshock (MES) test and rotarod test following intraperitoneal injection in KunMing mice. Among the synthesized compounds 3a-v, 7-(hexyloxy)-2H-benzo[b][1,4]thiazin-3(4H)-one (3f) could be considered potentially the most useful and safe therapeutic compound. Among the synthesized compounds 4a-u, compound 7-(2-fluorobenzyloxy)-4H-[1,2,4]triazolo[4,3-d]benzo[b][1,4]thiazine (4k) was the most active compound with an ED(50) of 17.0 mg/kg, TD(50) of 243.9 mg/kg and protective index (PI) of 14.3. Its neurotoxicity was lower than all the other synthesized compounds and also markedly lower than that of the reference drug carbamazepine.
Topics: Animals; Anticonvulsants; Drug Evaluation, Preclinical; Injections, Intraperitoneal; Mice; Molecular Structure; Motor Activity; Rotarod Performance Test; Seizures; Stereoisomerism; Thiazines
PubMed: 20190436
DOI: 10.1248/cpb.58.326 -
Psychopharmacology Nov 2021Pterostilbene is the 3,5-dimethoxy derivative of resveratrol with numerous beneficial effects including neuroprotective properties. Experimental studies revealed its...
Anticonvulsant effect of pterostilbene and its influence on the anxiety- and depression-like behavior in the pentetrazol-kindled mice: behavioral, biochemical, and molecular studies.
RATIONALE
Pterostilbene is the 3,5-dimethoxy derivative of resveratrol with numerous beneficial effects including neuroprotective properties. Experimental studies revealed its anticonvulsant action in the acute seizure tests.
OBJECTIVES
The purpose of the present study was to evaluate the effect of pterostilbene in the pentetrazol (PTZ)-induced kindling model of epilepsy in mice as well as to assess some possible mechanisms of its anticonvulsant action in this model.
METHODS
Mice were repeatedly treated with pterostilbene (50-200 mg/kg) and its effect on the development of seizure activity in the PTZ kindling was estimated. Influence of pterostilbene on the locomotor activity and anxiety- and depression-like behavior in the PTZ-kindled mice was also assessed. To understand the possible mechanisms of anticonvulsant activity of pterostilbene, γ-aminobutyric acid (GABA) and glutamate concentrations in the prefrontal cortex and hippocampus of the PTZ-kindled mice were measured using LC-MS/MS method. Moreover, mRNA expression of BDNF, TNF-α, IL-1β, IL-6, GABRA1A, and GRIN2B was determined by RT-qPCR technique.
RESULTS
We found that pterostilbene at a dose of 200 mg/kg considerably reduced seizure activity but did not influence the locomotor activity and depression- and anxiety-like behavior in the PTZ-kindled mice. In the prefrontal cortex and hippocampus, pterostilbene reversed the kindling-induced decrease of GABA concentration. Neither in the prefrontal cortex nor hippocampus pterostilbene affected mRNA expression of IL-1β, IL-6, GABRA1A, and GRIN2B augmented by PTZ kindling. Pterostilbene at a dose of 100 mg/kg significantly decreased BDNF and TNF-α mRNA expression in the hippocampus of the PTZ-kindled mice.
CONCLUSIONS
Although further studies are necessary to understand the mechanism of anticonvulsant properties of pterostilbene, our findings suggest that it might be considered a candidate for a new antiseizure drug.
Topics: Animals; Anticonvulsants; Anxiety; Chromatography, Liquid; Depression; Kindling, Neurologic; Mice; Pentylenetetrazole; Stilbenes; Tandem Mass Spectrometry
PubMed: 34333674
DOI: 10.1007/s00213-021-05933-5 -
International Journal of Molecular... Dec 2023Experimental studies reveal that caffeine (trimethylxanthine) at subconvulsive doses, distinctly reduced the anticonvulsant activity of numerous antiseizure medications... (Review)
Review
Experimental studies reveal that caffeine (trimethylxanthine) at subconvulsive doses, distinctly reduced the anticonvulsant activity of numerous antiseizure medications (ASMs) in rodents, oxcarbazepine, tiagabine and lamotrigine being the exceptions. Clinical data based on low numbers of patients support the experimental results by showing that caffeine (ingested in high quantities) may sharply increase seizure frequency, considerably reducing the quality of patients' lives. In contrast, this obviously negative activity of caffeine was not found in clinical studies involving much higher numbers of patients. ASMs vulnerable to caffeine in experimental models of seizures encompass carbamazepine, phenobarbital, phenytoin, valproate, gabapentin, levetiracetam, pregabalin and topiramate. An inhibition of R-calcium channels by lamotrigine and oxcarbazepine may account for their resistance to the trimethylxanthine. This assumption, however, is complicated by the fact that topiramate also seems to be a blocker of R-calcium channels. A question arises why large clinical studies failed to confirm the results of experimental and case-report studies. A possibility exists that the proportion of patients taking ASMs resistant to caffeine may be significant and such patients may be sufficiently protected against the negative activity of caffeine.
Topics: Humans; Lamotrigine; Oxcarbazepine; Caffeine; Topiramate; Anticonvulsants; Seizures; Calcium Channels
PubMed: 38139396
DOI: 10.3390/ijms242417569 -
International Journal of Molecular... Mar 2022Umbelliferone (7-hydroxycoumarin; UMB) is a coumarin with many biological properties, including antiepileptic activity. This study evaluated the effect of UMB on the...
Umbelliferone (7-hydroxycoumarin; UMB) is a coumarin with many biological properties, including antiepileptic activity. This study evaluated the effect of UMB on the ability of classical and novel antiepileptic drugs (e.g., lacosamide (LCM), levetiracetam (LEV), phenobarbital (PB) and valproate (VPA)) to prevent seizures evoked by the 6-Hz corneal-stimulation-induced seizure model. The study also evaluated the influence of this coumarin on the neuroprotective properties of these drugs in two in vitro models of neurodegeneration, including trophic stress and excitotoxicity. The results indicate that UMB (100 mg/kg, i.p.) significantly enhanced the anticonvulsant action of PB (p < 0.01) and VPA (p < 0.05), but not that of LCM orLEV, in the 6-Hz test. Whether alone or in combination with other anticonvulsant drugs (at their ED50 values from the 6-Hz test), UMB (100 mg/kg) did not affect motor coordination; skeletal muscular strength and long-term memory, as determined in the chimney; grip strength; or passive avoidance tests, respectively. Pharmacokinetic characterization revealed that UMB had no impact on total brain concentrations of PB or VPA in mice. The in vitro study indicated that UMB has neuroprotective properties. Administration of UMB (1 µg/mL), together with antiepileptic drugs, mitigated their negative impact on neuronal viability. Under trophic stress (serum deprivation) conditions, UMB enhanced the neurotrophic abilities of all the drugs used. Moreover, this coumarin statistically enhanced the neuroprotective effects of PB (p < 0.05) and VPA (p < 0.001) in the excitotoxicity model of neurodegeneration. The obtained results clearly indicate a positive effect of UMB on the anticonvulsant and neuroprotective properties of the selected drugs.
Topics: Animals; Anticonvulsants; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Electroshock; Lacosamide; Mice; Phenobarbital; Seizures; Umbelliferones
PubMed: 35408852
DOI: 10.3390/ijms23073492