Metixene hydrochloride hydrate has potential anticholinergic activity and inhibits the binding of quinine ring benzoate (QNB) to muscarine receptors, with IC50 and Ki values of 55 nM and 15 nM, respectively.

Otenzepad is a selective antagonist of M2 mAChR with IC50s of 386 nM and 640 nM for rat heart and rabbit peripheral lung.

9-Cyclopentyladenine (NSC-19486) is an adenylate cyclase inhibitor that blocks cellular morphological differentiation and phosphorylation of specific signaling molecules.