rwj-333369 and Disease-Models--Animal

Alcoholism is a complex heterogeneous disease and a number of neurotransmitter and neuromodulator systems have been implicated in its manifestation. Consequently, it is unlikely that existing medications such as disulfiram (Antabuse®), naltrexone (ReVia®), acamprosate (Campral®)) can be efficacious in every individual. Thus, the development of novel therapeutic agents with greater selectivity and less unwanted effects for the treatment of this disease is one of the major objectives of alcohol research. This review summarizes the findings of five novel compounds with different neuronal targets for treating alcoholism. These compounds include sazetidine-A, which selectively desensitizes α4β2 nicotinic receptors; carisbamate, a novel anti-epileptic agent; JNJ5234801, a novel anxiolytic agent; GS-455534, a highly selective inhibitor of mitochondrial aldehyde dehydrogenase; and JNJ-39220675, a selective histamine H3 antagonist. Inbred alcohol-preferring rats (iP), Fawn-Hooded (FH) rats, and P rats were used to evaluate the compounds. Naltrexone was used as a positive control in some experiments. All five compounds reduced alcohol consumption and preference. The mechanisms thought to underlie these effects suggest that, in addition to dopaminergic and opioidergic systems, other neuronal systems such as sodium channels (carisbamate), mitochondrial aldehyde dehydrogenase (GS-455534), 5-HT2 receptors (JNJ-5234801), histamine H3 receptors (JNJ-39220675), and α4β2 nicotinic receptors (sazetidine-A) can be involved in alcohol drinking. Further work is necessary to confirm the exact mechanisms of action of each drug and to determine any viable targets for putative treatment of alcohol-use disorders. The article presents some promising patents on novel medication targets for the treatment of alcoholism.

Topics: Alcohol Deterrents; Alcoholism; Animals; Azepines; Azetidines; Carbamates; Disease Models, Animal; Drug Evaluation, Preclinical; Drugs, Investigational; Humans; Isoflavones; Molecular Targeted Therapy; Patents as Topic; Piperidines; Pyridines; Synaptic Transmission

Topics: Acetamides; Animals; Anticonvulsants; Carbamates; Disease Models, Animal; Fructose; Humans; Lacosamide; Pyrroles; Pyrrolidinones; Rats; Receptors, AMPA; Status Epilepticus; Tetrahydroisoquinolines; Topiramate; Treatment Outcome

The authors evaluated the preclinical feasibility of acutely stabilizing an active bihemispheric limbic epileptic circuit using closed-loop direct neurostimulation therapy in tandem with "on-demand'" convection-enhanced intracerebral delivery of the antiepileptic drug (AED) carisbamate. A rat model of electrically induced self-sustained focal-onset epilepsy was employed.. A 16-contact depth-recording microelectrode was implanted bilaterally in the dentate gyrus (DG) of the hippocampus of Fischer 344 rats. The right microelectrode array included an integrated microcatheter for drug delivery at the distal tip. Bihemispheric spontaneous self-sustained limbic status epilepticus (SSLSE) was induced in freely moving rats using a 90-minute stimulation paradigm delivered to the right medial perforant white matter pathway. Immediately following SSLSE induction, closed-loop right PP stimulation therapy concurrent with on-demand nanoboluses of the AED [(14)C]-carisbamate (n = 4), or on-demand [(14)C]-carisbamate alone (n = 4), was introduced for a mean of 10 hours. In addition, 2 reference groups received either closed-loop stimulation therapy alone (n = 4) or stimulation therapy with saline vehicle only (n = 4). All animals were sacrificed after completing the specified therapy regimen. In situ [(14)C]-autoradiography was used to determine AED distribution.. Closed-loop direct stimulation therapy delivered unilaterally in the right PP aborted ictal runs detected in either ipsi- or contralateral hippocampi. Freely moving rats receiving closed-loop direct stimulation therapy with ondemand intracerebral carisbamate delivery experienced a significant reduction in seizure frequency (p < 0.001) and minimized seizure frequency variability during the final 50% of the therapy/recording session compared with closed-loop stimulation therapy alone.. Unilateral closed-loop direct stimulation therapy delivered to afferent hippocampal white matter pathways concurrent with on-demand ipsilateral intracerebral delivery of nano-bolused carisbamate can rapidly decrease the frequency of electrographic seizures in an active bihemispheric epileptic network. Additionally, direct pulsatile delivery of carisbamate can stabilize seizure frequency variability compared with direct stimulation therapy alone.

Topics: Animals; Anticonvulsants; Carbamates; Combined Modality Therapy; Disease Models, Animal; Electric Stimulation Therapy; Epilepsies, Partial; Male; Rats; Rats, Inbred F344; Treatment Outcome

Temporal lobe epilepsy is a relatively frequent, invalidating, and often refractory neurologic disorder. It is associated with cognitive impairments that affect memory and executive functions. In the rat lithium-pilocarpine temporal lobe epilepsy model, memory impairment and anxiety disorder are classically reported. Here we evaluated sustained visual attention in this model of epilepsy, a function not frequently explored.. Thirty-five Sprague-Dawley rats were subjected to lithium-pilocarpine status epilepticus. Twenty of them received a carisbamate treatment for 7 days, starting 1 h after status epilepticus onset. Twelve controls received lithium and saline. Five months later, attention was assessed in the five-choice serial reaction time task, a task that tests visual attention and inhibitory control (impulsivity/compulsivity). Neuronal counting was performed in brain regions of interest to the functions studied (hippocampus, prefrontal cortex, nucleus basalis magnocellularis, and pedunculopontine tegmental nucleus).. Lithium-pilocarpine rats developed motor seizures. When they were able to learn the task, they exhibited attention impairment and a tendency toward impulsivity and compulsivity. These disturbances occurred in the absence of neuronal loss in structures classically related to attentional performance, although they seemed to better correlate with neuronal loss in hippocampus. Globally, rats that received carisbamate and developed motor seizures were as impaired as untreated rats, whereas those that did not develop overt motor seizures performed like controls, despite evidence for hippocampal damage.. This study shows that attention deficits reported by patients with temporal lobe epilepsy can be observed in the lithium-pilocarpine model. Carisbamate prevents the occurrence of motor seizures, attention impairment, impulsivity, and compulsivity in a subpopulation of neuroprotected rats.

Topics: Animals; Anticonvulsants; Attention; Brain; Brain Mapping; Carbamates; Cell Count; Disease Models, Animal; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Executive Function; Inhibition, Psychological; Lithium Carbonate; Neurons; Pattern Recognition, Visual; Pilocarpine; Rats; Rats, Sprague-Dawley; Reaction Time; Serial Learning; Status Epilepticus

Administration of carisbamate during status epilepticus (SE) prevents the occurrence of motor seizures in the lithium-pilocarpine model and leads in a subpopulation of rats to spike-and-wave discharges characteristic of absence epilepsy. Widespread neuroprotection accompanied this change in seizure expression. To assess whether these carisbamate-induced changes affected comorbidity, we used a large battery of behavioral tests in rats that had developed temporal lobe or absence-like seizures.. Lithium-pilocarpine or saline was administered to 60 adult rats. Carisbamate (90 mg/kg) or diazepam and saline was given 1 h after SE onset, and repeated 8 h later and twice daily over 6 more days. Rats were video-monitored for 2 months. Subsequently, locomotor activity, anxiety, and various types of memory were assessed.. In rats with motor seizures, treated or not with carisbamate, all features of behavior were impaired compared to controls. Rats exhibiting absence-like seizures after carisbamate treatment behaved as controls in all paradigms tested along with widespread neuroprotection.. Carisbamate treatment leading to absence-like instead of temporal lobe seizures impressively prevented behavioral comorbidities reported by patients with epilepsy as the most disabling.

Topics: Animals; Anticonvulsants; Antipsychotic Agents; Behavior, Animal; Brain; Carbamates; Cell Count; Disease Models, Animal; Lithium; Male; Maze Learning; Memory; Mossy Fibers, Hippocampal; Muscarinic Agonists; Neurons; Phosphopyruvate Hydratase; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus; Visual Perception

Infantile spasms are the signature seizures of West syndrome. The conventional treatments for infantile spasms, such as adrenocorticotropic hormone (ACTH) and vigabatrin, are not always effective, especially in symptomatic infantile spasms (SIS). We tested the efficacy of carisbamate, a novel neurotherapeutic drug, to suppress spasms in the multiple-hit rat model of SIS, and compared it with phenytoin to determine if its effect is via sodium-channel blockade.. Sprague-Dawley rats received right intracerebral infusions of doxorubicin and lipopolysaccharide at postnatal day 3 (PN3) and intraperitoneal p-chlorophenylalanine at PN5. A single intraperitoneal injection of carisbamate was administered at PN4, after the onset of spasms, at the following doses: 10 mg/kg (CRS-10), 30 mg/kg (CRS-30), and 60 mg/kg (CRS-60), and was compared to vehicle-injected group (VEH). Video-monitoring of PN6-7 CRS-60 or VEH-injected pups was also done.. Carisbamate acutely reduced both behavioral spasms (CRS-30 and CRS-60 groups only) and electroclinical spasms during the first 2-3 postinjection hours, without detectable toxicity or mortality. In contrast, phenytoin (20 or 50 mg/kg) failed to suppress spasms.. Our findings provide preclinical evidence that carisbamate displays acute anticonvulsive effect on spasms through a sodium channel-independent mechanism. Because spasms in the multiple-hit rat model are refractory to ACTH and transiently sensitive to vigabatrin, carisbamate may constitute a candidate new therapy for SIS, including the ACTH-refractory spasms. Further confirmation with clinical studies is needed.

Topics: Animals; Animals, Newborn; Anticonvulsants; Behavior, Animal; Carbamates; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Humans; Infant; Infant, Newborn; Male; Phenytoin; Pregnancy; Rats; Rats, Sprague-Dawley; Spasm; Spasms, Infantile

Since 1994, when naltrexone (Revia) was approved by the FDA for the treatment of alcoholism, only 2 other drugs (Campral and Topamax have been approved for alcoholism treatment. However, various experimental drugs, including antiepileptic medications, have been tested in both animal models and in humans with some promising results. The purpose of this project was to study the effect of the novel neuromodulator carisbamate, which is in development for epilepsy treatment, on alcohol intake in selectively bred alcohol-preferring rats.. Male alcohol-preferring inbred P rats were allowed to freely drink water or alcohol (10%, v/v) using a 2-bottle choice procedure. After stable baselines for alcohol and water intakes were established, the acute effects of oral carisbamate (0, 10, 30, 45, 60, and 90 mg/kg) were assessed. Then, the chronic effect of the compound (60 mg/kg/day for 14 consecutive days) on alcohol intake was assessed in a separate group of male P rats. In another set of experiments, the effects of carisbamate and naltrexone on alcohol withdrawal-induced elevated drinking of alcohol, an index of craving, were compared. Rats were withdrawn from alcohol for 24 hours and were given vehicle, 20 mg/kg naltrexone or 60 mg/kg carisbamate 30 minutes before re-exposure to alcohol. Alcohol and water intake was measured 6 hours after alcohol re-exposure. To determine the effects of carisbamate on saccharin preference, rats were put on a 2-bottle choice of water versus a solution of 2% saccharin. Then, the effect of the highest dose of carisbamate (90 mg/kg) and naltrexone (20 mg/kg) and the vehicle on saccharin preference was determined.. Our results showed that there was a selective dose-dependent reduction in alcohol intake and preference in the alcohol-preferring P rat after an acute oral administration of carisbamate. There were no significant effects on food or water intake. Chronic administration of carisbamate significantly reduced alcohol intake and preference initially, but partial tolerance developed after the 10th treatment. The degree of tolerance development was less than that observed for naltrexone. Acute administration of carisbamate was more effective than naltrexone in reducing enhanced alcohol intake after a period of alcohol deprivation. Compared with control vehicle neither carisbamate nor naltrexone had a significant effect on saccharin intake and preference.. The novel neuromodulator compound carisbamate has a favorable profile of effects on alcohol intake and related measures and should be considered for testing on human alcoholics.

Topics: Administration, Oral; Alcohol Drinking; Animals; Anticonvulsants; Carbamates; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Rats; Time Factors

The antiepileptic effects of carisbamate were assessed in two models of genetic epilepsy, a model of absence seizures, the Genetic Absence Epilepsy Rat from Strasbourg (GAERS) and a model of convulsive seizures, the Wistar Audiogenic Sensitive (AS) rat.. GAERS were equipped with four cortical electrodes over the frontoparietal cortex and the duration of spike-and-wave discharges (SWD) was recorded for 20-120 min. In Wistar AS, the occurrence of, latency to, and duration of wild running and tonic seizures were recorded.. In GAERS, carisbamate (10, 30, and 60 mg/kg) dose dependently reduced the expression of SWD that totally disappeared at the two highest doses by 40 min after injection. SWD duration returned to control levels by 100 min after the injection of 30 mg/kg carisbamate while SWDs were totally suppressed for 120 min after the injection of 60 mg/kg carisbamate. In Wistar AS, 10 mg/kg carisbamate increased the latency to the first running episode and induced the occurrence of a second running episode in three of eight rats. This episode was not present in untreated rats and was indicative of decreased sensitivity to the stimulus. This dose of carisbamate increased by 327% the latency to the tonic seizure that still occurred in the six of eight rats studied. At 20 and 30 mg/kg, no rats exhibited any wild running or tonic seizure.. The present results support the broad spectrum of antiepileptic activity of carisbamate confirming its efficacy in animal models of primary generalized seizures of both tonic-clonic and of the absence type.

Topics: Animals; Anticonvulsants; Behavior, Animal; Carbamates; Cerebral Cortex; Disease Models, Animal; Dose-Response Relationship, Drug; Electroencephalography; Epilepsy, Absence; Epilepsy, Generalized; Epilepsy, Reflex; Frontal Lobe; Fructose; Male; Motor Activity; Parietal Lobe; Rats; Rats, Wistar; Reaction Time; Species Specificity; Topiramate

Animal models with spontaneous epileptic seizures may be useful in the discovery of new antiepileptic drugs (AEDs). The purpose of the present study was to evaluate the efficacy of carisbamate on spontaneous motor seizures in rats with kainate-induced epilepsy.. Repeated, low-dose (5 mg/kg), intraperitoneal injections of kainate were administered every hour until each male Sprague-Dawley rat had experienced convulsive status epilepticus for at least 3 h. Five 1-month trials (n = 8-10 rats) assessed the effects of 0.3, 1, 3, 10, and 30 mg/kg carisbamate on spontaneous seizures. Each trial involved six AED-versus-vehicle tests comprised of carisbamate or 10% solutol-HS-15 treatments administered as intraperitoneal injections on alternate days with a recovery day between each treatment day.. Carisbamate significantly reduced motor seizure frequency at doses of 10 and 30 mg/kg, and caused complete seizure cessation during the 6-h postdrug epoch in seven of the eight animals at 30 mg/kg. The effects of carisbamate (0.3-30 mg/kg) on spontaneous motor seizures appeared dose dependent.. These data support the hypothesis that a repeated-measures, crossover protocol in animal models with spontaneous seizures is an effective method for testing AEDs. Carisbamate reduced the frequency of spontaneous motor seizures in a dose-dependent manner, and was more effective than topiramate at reducing seizures in rats with kainate-induced epilepsy.

Topics: Analysis of Variance; Animals; Anticonvulsants; Carbamates; Cross-Over Studies; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Epilepsy; Fructose; Kainic Acid; Male; Rats; Rats, Sprague-Dawley; Seizures; Time Factors; Topiramate; Video Recording

Carisbamate is a novel drug with neuromodulator activity that is currently under development for the treatment of epilepsy, diabetic neuropathy and neuralgia. The compound possessed a promising pharmacological profile in tests in vivo, and demonstrated broad anticonvulsant activity in preclinical studies, both elevating seizure threshold and preventing seizure spread. Carisbamate was also effective in protecting against spontaneous recurrent seizures in kainate-treated animals and in genetic models of epilepsy, and displayed antiepileptic and neuroprotective activity in the lithium-pilocarpine model of status epilepticus. In a phase I clinical trial, orally administered carisbamate demonstrated efficacy at high doses of 500 to 1000 mg. A phase II clinical trial confirmed that oral carisbamate was efficacious at a 300- to 1600-mg dose range. The preliminary evaluations of carisbamate in humans indicated complete absorption, extensive metabolism, and carbamate ester hydrolysis. The most frequently reported side effects associated with carisbamate are dizziness, headache, somnolence and nausea. In clinical trials, carisbamate did not display any significant interactions with commonly used antiepileptic drugs such as carbamazepine, valproate and lamotrigine. At the time of publication, a phase III clinical trial for carisbamate in the treatment of epilepsy was ongoing, as well as phase II trials in neuropathy and neuralgia. Data from preclinical brain injury studies with carisbamate and the analog RWJ-333369-A have also been reported. This drug profile will focus on the development of carisbamate in epilepsy.

Topics: Animals; Anticonvulsants; Carbamates; Controlled Clinical Trials as Topic; Disease Models, Animal; Drug Evaluation, Preclinical; Epilepsy; Humans; Patents as Topic