Cevimeline hydrochloride hemihydrate is a novel and selective agonist of muscarinic acetylcholine receptor [1].

Muscarinic acetylcholine receptors (mAChRs) are acetylcholine receptors and mediate serous-saliva secretion and tear secretion. It is more sensitive to muscarine than nicotine [1].

Cevimeline hydrochloride hemihydrate induced contractions of isolated guinea pig ilea and trachea with EC50 values of 3.5 and 3 μM, respectively. Binding studies indicated that Cevimeline hydrochloride hemihydrate was a potent and highly selective M1-type muscarinic agonist. Also, it had a higher affinity for M1 receptors than other M1 agonists [2].

In normal rats and mice, X-irradiated saliva secretion defective rats and two strains of autoimmune disease mice, intraduodenal administrations of SNI-2011 (3-30 mg/kg) increased saliva and tear secretions in a dose-dependent way, which suggested that Cevimeline hydrochloride hemihydrate directly stimulated muscarinic receptors in salivary and lacrimal glands for saliva and tear secretions [1].

References:
[1].  Iga Y, Arisawa H, Ogane N, et al. (+/-)-cis-2-methylspiro[1,3-oxathiolane-5,3'-quinuclidine] hydrochloride, hemihydrate (SNI-2011, cevimeline hydrochloride) induces saliva and tear secretions in rats and mice: the role of muscarinic acetylcholine receptors. Jpn J Pharmacol, 1998, 78(3): 373-380.
[2].  Fisher A, Brandeis R, Karton I, et al. (+-)-cis-2-methyl-spiro(1,3-oxathiolane-5,3') quinuclidine, an M1 selective cholinergic agonist, attenuates cognitive dysfunctions in an animal model of Alzheimer's disease. J Pharmacol Exp Ther, 1991, 257(1): 392-403.