clozapine and asenapine

Insufficient treatment of psychosis often manifests as violent and aggressive behaviors that are dangerous to the patient and others, and that warrant treatment strategies which are not considered first-line, evidence-based practices. Such treatment strategies include both antipsychotic polypharmacy (simultaneous use of 2 antipsychotics) and high-dose antipsychotic monotherapy. Here we discuss the hypothesized neurobiological substrates of various types of violence and aggression, as well as providing arguments for the use of antipsychotic polypharmacy and high-dose monotherapy to target dysfunctional neurocircuitry in the subpopulation of patients that is treatment-resistant, violent, and aggressive. In this review, we focus primarily on the data supporting the use of second-generation, atypical antipsychotics both at high doses and in combination with other antipsychotics.

Topics: Antipsychotic Agents; Aripiprazole; Benzodiazepines; Brain; Clozapine; Dibenzocycloheptenes; Drug Therapy, Combination; Heterocyclic Compounds, 4 or More Rings; Humans; Impulsive Behavior; Isoxazoles; Lurasidone Hydrochloride; Olanzapine; Paliperidone Palmitate; Piperazines; Piperidines; Polypharmacy; Psychotic Disorders; Quetiapine Fumarate; Receptors, Dopamine D2; Risperidone; Thiazoles; Violence

Topics: Antipsychotic Agents; Brain; Clozapine; Dibenzocycloheptenes; Heterocyclic Compounds, 4 or More Rings; Humans; Isoxazoles; Paliperidone Palmitate; Piperidines; Pyrimidines; Receptors, Neurotransmitter

Asenapine maleate (AM) is an atypical antipsychotic that, unlike many other antipsychotics, shows some efficacy in treating cognitive dysfunction in schizophrenia. Normal cognitive function has long since been associated with high frequency neuronal oscillations. However, recent research has highlighted the potential importance of low frequency oscillations. Here, the impact of AM on low frequency neural oscillatory activity was evaluated in the methylazoxymethanol acetate (MAM) rat model system used for the study schizophrenia, and the oscillatory signatures compared to those of haloperidol (HAL) and clozapine (CLZ). AM and CLZ normalized low frequency spectral power deficits in the prefrontal cortex, while HAL and AM reversed corticostriatal and corticocortical delta coherence deficits. However, only chronic AM administration normalized corticostriatal and corticocortical delta coherence deficits between 3-4 Hz. These findings support the idea that antipsychotic-induced amelioration of both delta coherence and power may be important for therapeutic efficacy in treating the cognitive deficits inherent in schizophrenia.

Topics: Animals; Antipsychotic Agents; Brain; Clozapine; Delta Rhythm; Dibenzocycloheptenes; Disease Models, Animal; Haloperidol; Heterocyclic Compounds, 4 or More Rings; Rats; Rats, Sprague-Dawley; Schizophrenia

Asenapine is an atypical antipsychotic that is currently available for the treatment of schizophrenia and bipolar I disorder. Although the atypical antipsychotics clozapine and olanzapine are effective for depression and anxiety in schizophrenia, as demonstrated by animal model studies, this has not been clarified for asenapine. Therefore, we compared the effects of asenapine in the conditioned fear stress model with those of clozapine and olanzapine.. Rats were individually fear conditioned using electrical foot shock in a Skinner box. Approximately 24 h later, individual animals were returned to the same Skinner box (without electrical shock) and their freezing behaviour was observed for 5 min. Animals were treated with asenapine, clozapine, olanzapine, the 5-HT1A receptor partial agonist buspirone, or the 5-HT2C receptor antagonist SB242084 at 30 min before freezing behaviour assessment. The 5-HT1A receptor antagonist WAY100635 or the 5-HT2C receptor agonist Ro60-0175 was also used concomitantly with asenapine. The effects of asenapine, clozapine, and olanzapine on serotonin release in the rat hippocampus were also measured using in vivo microdialysis.. Asenapine reduced freezing behaviour, while neither clozapine nor olanzapine reduced freezing behaviour. Buspirone and SB242084 also reduced freezing behaviour. The effect of asenapine in reducing freezing behaviour was not altered by the concomitant administration of WAY100635 or Ro60-0175. Both asenapine and clozapine, but not olanzapine, increased serotonin release in the rat hippocampus.. Asenapine may have superior therapeutic effect on anxiety symptoms than other agents, although the underlying mechanism of its anxiolytic activity remains unknown.

Topics: Aminopyridines; Animals; Anti-Anxiety Agents; Antipsychotic Agents; Anxiety; Benzodiazepines; Buspirone; Clozapine; Conditioning, Classical; Dibenzocycloheptenes; Disease Models, Animal; Dose-Response Relationship, Drug; Electroshock; Fear; Heterocyclic Compounds, 4 or More Rings; Hippocampus; Indoles; Male; Olanzapine; Rats; Rats, Sprague-Dawley; Serotonin; Serotonin Antagonists; Serotonin Receptor Agonists; Stress, Psychological

Among several commonly used atypical antipsychotic drugs, olanzapine and risperidone cause a sensitization effect in the conditioned avoidance response (CAR) and phencyclidine (PCP)-induced hyperlocomotion paradigms--two well established animal tests of antipsychotic drugs, whereas clozapine causes a tolerance effect. Asenapine is a novel antipsychotic drug recently approved for the treatment of schizophrenia and manic disorders. It shares several receptor binding sites and behavioral features with other atypical antipsychotic drugs. However, it is not clear what type of repeated effect (sensitization or tolerance) asenapine would induce, and whether such an effect is transferrable to other atypicals. In this study, male adult Sprague-Dawley rats were first repeatedly tested with asenapine (0.05, 0.10 or 0.20 mg/kg, sc) for avoidance response or PCP (3.20 mg/kg, sc)-induced hyperlocomotion daily for 5 consecutive days. After 2-3 days of retraining/drug-free recovery, they were then challenged with asenapine (0.10 mg/kg, sc), followed by olanzapine (0.50 mg/kg, sc) and clozapine (2.50 mg/kg, sc). During the 5-day drug test period (the induction phase), repeated asenapine treatment progressively increased its inhibition of avoidance response and PCP-induced hyperlocomotion in a dose-dependent fashion. On the asenapine and olanzapine challenge tests (the expression phase), rats previously treated with asenapine still showed significantly lower avoidance response and lower PCP-induced hyperlocomotion than those previously treated with vehicle. An increased reactivity to clozapine challenge in prior asenapine-treated rats was also found in the PCP-induced hyperlocomotion test. These findings suggest that asenapine is capable of inducing a sensitization effect and a cross-sensitization to olanzapine and clozapine (to a lesser extent). Because the behavioral profile of asenapine in both tests is similar to that of olanzapine, but different from that of clozapine, we suggest that asenapine resembles olanzapine to a greater extent than clozapine in its therapeutic and side effect profiles.

Topics: Analysis of Variance; Animals; Antipsychotic Agents; Avoidance Learning; Benzodiazepines; Clozapine; Dibenzocycloheptenes; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Evaluation, Preclinical; Heterocyclic Compounds, 4 or More Rings; Hyperkinesis; Male; Motor Activity; Olanzapine; Phencyclidine; Rats; Rats, Sprague-Dawley

Asenapine is a novel psychopharmacologic agent under development for the treatment of schizophrenia and bipolar disorder. We determined and compared the human receptor binding affinities and functional characteristics of asenapine and several antipsychotic drugs. Compounds were tested under comparable assay conditions using cloned human receptors. In comparison with the antipsychotics, asenapine showed high affinity and a different rank order of binding affinities (pKi) for serotonin receptors (5-HT1A [8.6], 5-HT1B [8.4], 5-HT2A [10.2], 5-HT2B [9.8], 5-HT2C [10.5], 5-HT5 [8.8], 5-HT6 [9.6] and 5-HT7 [9.9]), adrenoceptors (alpha1 [8.9], alpha2A [8.9], alpha2B [9.5] and alpha2C [8.9]), dopamine receptors (D1 [8.9], D2 [8.9], D3 [9.4] and D4 [9.0]) and histamine receptors (H1 [9.0] and H2 [8.2]). It had much lower affinity (pKi

Topics: Benzodiazepines; Bipolar Disorder; Clinical Trials as Topic; Cloning, Molecular; Clozapine; Dibenzocycloheptenes; Heterocyclic Compounds, 4 or More Rings; Histamine Release; Humans; Inhibitory Concentration 50; Molecular Structure; Olanzapine; Psychotropic Drugs; Radioligand Assay; Receptors, Adrenergic; Receptors, Dopamine; Receptors, Dopamine D2; Receptors, Muscarinic; Receptors, Serotonin; Schizophrenia; Substrate Specificity

trans-5-Chloro-2-methyl-2,3,3a,12b-tetrahydro-1H- dibenz[2,3:6,7]oxepinol[4,5-c]pyrrolidine maleate (Org 5222) is a new compound with effects on animal behaviour indicating strong antipsychotic potential based on antagonism of dopaminergic and serotonergic effects. The compound inhibits apomorphine-induced climbing behaviour, mouse locomotor activity, rat activity in an open field, shuttle box behaviour in rats, pergolide induced circling in 6-hydroxydopamine(6-OHDA) lesioned rats, serotonin agonist-induced forepaw treading, head shakes and penile erections. The compound is less effective in inducing catalepsy, and antagonising SKF-38393 (tetrahydro- 1-phenyl-1H-3-benzazepine-7,8-diol HCl)-induced circling in 6-OHDA-lesioned rats and it does not induce perioral movements in rats. Based on these data and the neurochemical profile of the compound it was decided that this compound merits clinical investigation in a programme aiming for an effective antipsychotic agent with reduced risks of extrapyramidal side-effects.

Topics: Animals; Antipsychotic Agents; Avoidance Learning; Behavior, Animal; Catalepsy; Chlorpromazine; Clozapine; Conflict, Psychological; Dibenzocycloheptenes; Dibenzoxepins; Haloperidol; Heterocyclic Compounds, 4 or More Rings; Male; Mice; Mice, Inbred ICR; Motor Activity; Rats; Rats, Inbred Strains; Receptors, Dopamine; Receptors, Serotonin; Stereotyped Behavior