Antiinflammatory drugs achieve their therapeutic actions at least in part by regulation of cytokine formation. A “cytokine hypothesis” of depression is supported by the observation that depressed individuals have elevated plasma levels of certain cytokines compared with healthy controls. Here we investigated a possible interaction between antidepressant agents and antiinflammatory agents on antidepressant-induced behaviors and on p11, a biochemical marker of depressive-like states and antidepressant responses. We found that widely used antiinflammatory drugs antagonize both biochemical and behavioral responses to selective serotonin reuptake inhibitors (SSRIs). In contrast to the levels detected in serum, we found that frontal cortical levels of certain cytokines (e.g., TNFα and IFNγ) were increased by serotonergic antidepressants and that these effects were inhibited by antiinflammatory agents. The antagonistic effect of antiinflammatory agents on antidepressant-induced behaviors was confirmed by analysis of a dataset from a large-scale real-world human study, “sequenced treatment alternatives to relieve depression” (STAR*D), underscoring the clinical significance of our findings. Our data indicate that clinicians should carefully balance the therapeutic benefits of antiinflammatory agents versus the potentially negative consequences of antagonizing the therapeutic efficacy of antidepressant agents in patients suffering from depression.

The muscarinic receptor agonist activities of NDMC are unique among antipsychotics, and provide a possible molecular basis for the superior clinical effects of clozapine pharmacotherapy.

The in vitro and in vivo pharmacological properties of N-(4-fluorophenylmethyl)-N-(1-methylpiperidin-4-yl)-NЈ-(4-( (Snyder, 1976;Carlsson et al., 1999a). Unfortunately, antagonism of D 2 receptors also causes profound motor, endocrine, and cognitive side effects, which can 1 Current affiliation: TorreyPines Therapeutics,

Schizophrenia is a chronic and debilitating neuropsychiatric disorder affecting approximately 1% of the world’s population. This disease is associated with considerable morbidity placing a major financial burden on society. Antipsychotics have been the mainstay of the pharmacological treatment of schizophrenia for decades. The traditional typical and atypical antipsychotics demonstrate clinical efficacy in treating positive symptoms, such as hallucinations and delusions, while are largely ineffective and may worsen negative symptoms, such as blunted affect and social withdrawal, as well as cognitive function. The inability to treat these latter symptoms may contribute to social function impairment associated with schizophrenia. The dysfunction of multiple neurotransmitter systems in schizophrenia suggests that drugs selectively targeting one neurotransmission pathway are unlikely to meet all the therapeutic needs of this heterogeneous disorder. Often, however, the unintentional engagement of multiple pharmacological targets or even the excessive engagement of intended pharmacological targets can lead to undesired consequences and poor tolerability. In this article, we will review marketed typical and atypical antipsychotics and new therapeutic agents targeting dopamine receptors and other neurotransmitters for the treatment of schizophrenia. Representative typical and atypical antipsychotic drugs and new investigational drug candidates will be systematically reviewed and compared by reviewing structure-activity relationships, pharmacokinetic properties, drug metabolism and safety, pharmacological properties, preclinical data in animal models, clinical outcomes and associated side effects.

RationaleSchizophrenia remains among the most prevalent neuropsychiatric disorders, and current treatment options are accompanied by unwanted side effects. New treatments that better address core features of the disease with minimal side effects are needed.ObjectivesAs a new therapeutic approach, 1-(4-fluoro-phenyl)-4-((6bR, 10aS)-3-methyl-2,3,6b,9,10,10a-hexahydro-1H,7H-pyrido[3′,4′:4,5]pyrrolo[1,2,3-de]quinoxalin-8-yl)-butan-1-one (ITI-007) is currently in human clinical trials for the treatment of schizophrenia. Here, we characterize the preclinical functional activity of ITI-007.ResultsITI-007 is a potent 5-HT2A receptor ligand (Ki = 0.5 nM) with strong affinity for dopamine (DA) D2 receptors (Ki = 32 nM) and the serotonin transporter (SERT) (Ki = 62 nM) but negligible binding to receptors (e.g., H1 histaminergic, 5-HT2C, and muscarinic) associated with cognitive and metabolic side effects of antipsychotic drugs. In vivo it is a 5-HT2A antagonist, blocking (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI)-induced headtwitch in mice with an inhibitory dose 50 (ID50) = 0.09 mg/kg, per oral (p.o.), and has dual properties at D2 receptors, acting as a postsynaptic D2 receptor antagonist to block D-amphetamine hydrochloride (D-AMPH) hyperlocomotion (ID50 = 0.95 mg/kg, p.o.), yet acting as a partial agonist at presynaptic striatal D2 receptors in assays measuring striatal DA neurotransmission. Further, in microdialysis studies, this compound significantly and preferentially enhances mesocortical DA release. At doses relevant for antipsychotic activity in rodents, ITI-007 has no demonstrable cataleptogenic activity. ITI-007 indirectly modulates glutamatergic neurotransmission by increasing phosphorylation of GluN2B-type N-methyl-d-aspartate (NMDA) receptors and preferentially increases phosphorylation of glycogen synthase kinase 3β (GSK-3β) in mesolimbic/mesocortical dopamine systems.ConclusionThe combination of in vitro and in vivo activities of this compound support its development for the treatment of schizophrenia and other psychiatric and neurologic disorders.