Which cholinergic agent is commonly prescribed to lower intraocular pressure in glaucoma?

Pilocarpine is commonly prescribed to lower intraocular pressure in patients with glaucoma due to its mechanism of action as a direct-acting cholinergic agonist. When administered, Pilocarpine stimulates muscarinic receptors in the eye, leading to contraction of the ciliary muscle. This contraction facilitates drainage of the aqueous humor through the trabecular meshwork, resulting in a decrease in intraocular pressure. This pharmacological effect is particularly beneficial for managing conditions like open-angle glaucoma and acute angle-closure glaucoma.

The other choices do not have the same application for lowering intraocular pressure. Donepezil is primarily used in the treatment of Alzheimer's disease to enhance cholinergic function in the brain. Neostigmine is an acetylcholinesterase inhibitor used mainly for myasthenia gravis; it increases acetylcholine levels at neuromuscular junctions but does not directly affect intraocular pressure. Scopolamine is an anticholinergic agent used mainly for motion sickness and does not have a role in managing glaucoma. Therefore, Pilocarpine stands out as the appropriate choice for this specific therapeutic indication.