Current pharmaceutical design
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This article reviews our current understanding of the relationships between critical illness, circadian disruption, and delirium. ⋯ Delirium is a common and morbid complication of hospitalization, particularly in the setting of critical illness and intensive care unit (ICU) admission. Critical illness involves a host of acute metabolic, hormonal and inflammatory responses that appear to disrupt normal sleep architecture and precipitate cerebral dysfunction. The intervention-heavy environment of the ICU further disrupts normal circadian rhythms and increases delirium risk. Despite strong evidence for correlation of sleep disruption, critical illness and delirium, causal relationships remain difficult to prove. Delirium is almost certainly a multifactorial condition. This article reviews proposed pathophysiologic mechanisms and potential therapeutic targets. In the absence of definitive pharmacologic therapy, interventions prioritizing maintenance of normal circadian, sleep, and behavioral patterns have shown promise in delirium risk reduction.
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Pomaglumetad methionil (LY2140023) is a mGlu2/3 receptor agonist prodrug reported in 2007 to possess antipsychotic efficacy based on results of a phase 2 trial conducted entirely in Russia using in-patients with schizophrenia. Since that time, pomaglumetad methionil failed to demonstrate antipsychotic efficacy compared to placebo in three phase 2 or phase 3 trials, despite risperidone separating from placebo in one phase 3 trial. ⋯ Orthogonal to these results with the mGlu2/3 receptor agonist prodrug, a 5-HT2A receptor inverse agonist pimavanserin demonstrated antipsychotic efficacy in subjects with Parkinson's disease (PD) psychosis despite limited and at best modest evidence of antipsychotic efficacy for a number of selective 5-HT2A receptor antagonists in subjects with schizophrenia. Based on the precedent for pimavanserin in PD psychosis, the known overlapping preclinical profile of mGlu2/3 receptor agonists and 5-HT2A receptor antagonists/inverse agonists and the neurobiology of other psychosis associated with neurodegenerative illness, there remains open a hypothesis that mGlu2/3 receptor agonists may exert clinically significant antipsychotic effects in PD psychosis, dementia with Lewy Bodies, and Alzheimer's disease psychosis.