Dipivefrin is a prodrug of epinephrine used in ophthalmic solutions to reduce intraocular pressure in chronic open-angle glaucoma. It is available as ophthalmic solution (eye drops). Dipivefrin is a prodrug with little or no pharmacologically activity until it is hydrolyzed into epinephrine inside the human eye. The liberated epinephrine, an adrenergic agonist, appears to exert its action by stimulating α -and/or β2-adrenergic receptors, leading to a decrease in aqueous production and an enhancement of outflow facility. The dipivefrin prodrug delivery system is a more efficient way of delivering the therapeutic effects of epinephrine, with fewer side effects than are associated with conventional epinephrine therapy. Epinephrine reduces the amount of aqueous humour fluids, effectively reducing the intraocular pressure, by activating the alpha-2 adrenergic receptors. Aqueous production decreases when ciliary blood flow is reduced by lowering the ocular perfusion pressure, and hypothesized that drug-induced reduction of ciliary blood flow would also decrease aqueous production. Stimulation of α2 receptors by reduces production by decreasing cAMP. The alpha-2 receptor acts as an allosteric inhibitor through Gi function, leading to an inhibition of adenylyl cyclase, decreasing the formation of intracellular cAMP leading to muscle contraction in smooth muscle. This muscle contraction of the ciliary vessel smooth muscle causes the blood vessels of the eye to contract and reduce aqueous humour productiion. Some side effects of dipivefrin may include irregular heartbeat, increased blood pressure, pain or swelling of the eye, skin rash, and eye watering.

Dipivefrin A2-Adrenergic Vasocontriction Pathway References