Ripasudil is a pharmaceutical compound specifically developed for ophthalmic use. It is categorized as a Rho kinase (ROCK) inhibitor, a class of drugs that work to reduce pressure within the eye. This medication is primarily available as eye drops and was first approved for use in Japan in 2014 under the trade name Glanatec. It manages eye conditions by influencing fluid dynamics within the eye.
Primary Medical Application
Ripasudil is used to treat open-angle glaucoma and ocular hypertension. Glaucoma is a serious eye condition characterized by damage to the optic nerve, often linked to elevated intraocular pressure (IOP). If left untreated, this pressure can lead to irreversible vision loss and even blindness. Ocular hypertension refers to elevated eye pressure without immediate signs of optic nerve damage, but it carries an increased risk of developing glaucoma.
Ripasudil is often prescribed when other initial treatments, such as prostaglandin analogues or beta-blockers, are not sufficient to control eye pressure. It can be used as an add-on therapy, providing an additional mechanism to reduce IOP. Studies have shown that ripasudil can significantly reduce IOP in patients, including those with uncontrolled glaucoma despite maximal topical medications.
Mechanism of Action
Ripasudil acts as a selective inhibitor of Rho-associated coiled-coil-containing protein kinase (ROCK), specifically targeting both ROCK-1 and ROCK-2 isoforms. These enzymes play a role in regulating the actin cytoskeleton, which influences the contractility and permeability of cells in the eye’s drainage system. By inhibiting Rho kinase, ripasudil causes changes in the trabecular meshwork, a spongy tissue located at the angle of the eye that is responsible for draining aqueous humor.
Inhibition of Rho kinase by ripasudil leads to the relaxation of the trabecular meshwork cells. This relaxation reduces the compaction of the tissue and increases the spaces between cells, which in turn enhances the outflow of aqueous humor from the eye. The improved drainage through Schlemm’s canal, the primary outflow pathway, helps to decrease intraocular pressure. This mechanism of increasing aqueous humor outflow differentiates it from other glaucoma medications that might focus on reducing fluid production.
Administration and Safety Information
Patients are typically advised to wash their hands before applying the drops and to instill the prescribed number of drops into the affected eye. After application, closing the eyes for one to two minutes and gently pressing the inner corner of the eye helps with absorption. If multiple eye drops are needed, a waiting period of five to ten minutes between applications is recommended to prevent one drop from washing away another.
Common side effects of ripasudil include eye redness (conjunctival hyperemia), eye irritation, and inflammation of the eyelids (blepharitis). Conjunctival hyperemia is a common side effect, but it is generally mild and temporary. Less common effects may include itching or increased tear production. Patients should remove contact lenses before applying the drops and wait at least 15 minutes before reinserting them. It is important to inform a healthcare professional about any allergies, pregnancy, breastfeeding, or other medications, including supplements, to ensure safe use.