Indications
Dapiprazole is primarily indicated for the management of iatrogenically induced mydriasis, which can result from the application of adrenergic agents, such as phenylephrine, or parasympatholytic agents, like tropicamide, during ophthalmic examinations. Its use facilitates the reversal of pupil dilation, aiding in the restoration of normal visual function following diagnostic procedures.
Pharmacodynamics
As an alpha-adrenergic blocking agent, Dapiprazole exerts its effects by antagonizing alpha-adrenergic receptors located on the dilator muscle of the iris. This action induces miosis, or pupil constriction. Notably, Dapiprazole does not significantly impact the ciliary muscle's ability to contract, ensuring stability in the anterior chamber depth and lens thickness. Additionally, it does not alter intraocular pressure (IOP) in either normal eyes or those with elevated IOP. The agent may exhibit a marginally slower rate of pupillary constriction in individuals with brown irises compared to those with blue or green irises.
Absorption
The systemic absorption of Dapiprazole following topical administration is negligible. This limited absorption profile minimizes systemic exposure and reduces the potential for systemic side effects, emphasizing its targeted ophthalmic application.
Mechanism of Action
Dapiprazole exerts its effects by selectively antagonizing alpha1-adrenergic receptors located in the smooth muscle. Its primary action is to induce miosis by targeting the dilator muscle of the iris. Importantly, Dapiprazole does not significantly affect the contraction of the ciliary muscle. Consequently, there is no notable alteration in the anterior chamber depth or in the thickness of the lens.
