Opthalmic α-Adrenoreceptor Agonists

For the treatment of glaucoma

α-Adrenoreceptor Agonists can be applied topically to decrease production of aqueous humor. Ophthalmic α₂ agonists include brimonidine and apraclonidine. By activating α₂ receptors in the ciliary epithelium, adenylyl cyclase becomes inhibited and cyclic adenosine monophosphate (cAMP) is no longer formed. This hinders ion transport and, thus, fluid production. Over time, these medications appear to improve fluid outflow as well. Adverse effects can include contact dermatitis, dry mouth, headache, hypotension, and somnolence. Use of α₂ agonists is contraindicated with concurrent monoamine oxidase inhibitor (MAOI) therapy due to pronounced hypotension.