Design, synthesis, and behavioral evaluation of dual-acting compounds as phosphodiesterase type 10A (PDE10A) inhibitors and serotonin ligands targeting neuropsychiatric symptoms in dementia

Neuropsychiatric symptoms (NPS), such as psychosis, depression and anxiety are frequently observed among patients with dementia. NPS is treated by off-label psychotropic medications that are only modestly effective in dementia patients, with a high risk of adverse events and cognitive decline. Considering the above, there is an unmet need for a well-tolerated and effective therapy of NPS in dementia. We designed and synthesized a library of dual-acting compounds as phosphodiesterase type-10A inhibitors and serotonin 5-HT_1AR ligands. The most potent molecules, compounds 4 and 8, as partial agonists of 5-HT_1AR and PDE10A inhibitors, exhibited a very high permeability of the blood-brain barrier. Compounds 4 and 8 displayed antipsychotic- and antidepressant-like activity and restored recognition memory deficits in mice. The overall effectiveness, pharmacokinetic and bioavailability studies imply the therapeutic-like potential of the presented dual-acting compounds as a method of treatment of NPS in dementia.