Muscarinic agonist

Overview
A muscarinic receptor agonist is an agent that enhances the activity of the muscarinic acetylcholine receptor. The muscarinic receptor has different subtypes, labelled M1-M5, allowing for further differentiation.

In the form of pilocarpine muscarinic receptor agonists have been used medically for a long time.

M1-type muscarinic acetylcholine receptors play a role in cognitive processing. In Alzheimer disease (AD) amyloid formation may decrease the ability of these receptors to transmit their signals leading to decrease cholinergic activity. As these receptors themselves appear relatively unchanged in the disease process, they have become a potential therapeutic target when trying to improve cognitive function in patients with AD.

A number of muscarinic agonists have been developed and are under investigation to treat AD. These agents show promise as they are neurotrophic, decrease amyloid depositions, and improve damage due to oxidative stress. Tau-phosphorylation is decreased and  cholinergic function enhanced. Notably several agents of the AF series of muscarinic agonists have become the focus of such research:. AF102B, AF150(S), AF267B. In animal models that are mimicking the damage of AD, these agents appear promising.

Drugs

 * M1 agonists
 * Cevimeline (AF102B) (Evoxac) is a muscarinic agonist that is an Food and Drug Administration (FDA)-approved drug and used for the management of  dry mouth in Sjögren's syndrome.
 * M3 agonists
 * Aceclidine, for glaucoma.
 * Arecoline, an alkaloid present in the Betel nut.
 * Pilocarpine is a drug that acts as a muscarinic receptor agonist that is used to treat glaucoma.