D. Pilocarpine

The alkaloid pilocarpine is a tertiary amine and is stable to hydrolysis by AChE. Compared with ACh and its derivatives, it is far less potent but is uncharged and will penetrate the CNS at therapeutic doses. Pilocarpine exhibits muscarinic activity and is used primarily in ophthalmology.Activates muscarinic (M) receptors • increases IP3 and DAG may also activate EPSP via M receptors in ganglia