Dicyclomine (hydrochloride)

Dicyclomine hydrochloride is a potent and orally active muscarinic cholinergic receptors antagonist. Dicyclomine hydrochloride shows high affinity for muscarinic M1 receptor subtype (K_i=5.1 nM) and M2 receptor subtype (K_i=54.6 nM) in brush-border membrane and basal plasma membranes, respectively^[1]. Dicyclomine is an antispasmodic agent and relieves smooth muscle spasm of the gastrointestinal tract in vivo^[2]. IC50 & Target: Ki: 5.1 nM (muscarinic M1 receptor subtype in brush-border membrane)
Ki: 54.6 nM (muscarinic M2 receptor subtype in basal plasma membrane^[1] In Vivo: Dicyclomine hydrochloride (intraperitoneal injection; 8 mg/kg; daily) exacerbates the cognitive impairments in all the measurements. In addition, the memory impairments are worse in dicyclomine-treated 3xTg-AD mice compared to dicyclomine-treated NonTg mice^[2].
Dicyclomine hydrochloride (intraperitoneal injection; 2.0, 4.0, and 8.0 mg/kg; 7 days) produces a highly significant effect on performance in the paired-associates learning (PAL) task in mice.And systemic treatment at lower doses show behavioral impairments in mice in spatial tasks^[3].