Pharmacology and Therapeutic Potential of Benzothiazole Analogues for Cocaine Use Disorder.

Pharmacological targeting of the dopamine D4 receptor (D4 R)─expressed in brain regions that control cognition, attention, and decision-making─could be useful for several neuropsychiatric disorders including substance use disorders (SUDs). This study focused on the synthesis and evaluation of a novel series of benzothiazole analogues designed to target D4 R. We identified several compounds with high D4 R binding affinity ( Ki ≤ 6.9 nM) and >91-fold selectivity over other D2 -like receptors (D2 R, D3 R) with diverse partial agonist and antagonist profiles. Novel analogue 16f is a potent low-efficacy D4 R partial agonist, metabolically stable in rat and human liver microsomes, and has excellent brain penetration in rats (AUCbrain/plasma > 3). 16f (5-30 mg/kg, i.p.) dose-dependently decreased iv cocaine self-administration in rats, consistent with previous results produced by D4 R-selective antagonists. Off-target antagonism of 5-HT2A or 5-HT2B may also contribute to these effects. Results with 16f support further efforts to target D4 R in SUD treatment.