Rhokiinsa: Uses, Dosage & Side Effects
A Rho-kinase inhibitor eye drop for reducing elevated intraocular pressure in adults with open-angle glaucoma or ocular hypertension
Rhokiinsa (netarsudil) is a prescription eye drop used to lower elevated intraocular pressure (IOP) in adults with open-angle glaucoma or ocular hypertension. It belongs to a novel class of glaucoma medications known as Rho-kinase (ROCK) inhibitors, which work primarily by increasing the drainage of aqueous humor through the trabecular meshwork and reducing episcleral venous pressure. Rhokiinsa is administered as one drop in the affected eye(s) once daily in the evening and is manufactured by Santen Oy. Clinical trials have demonstrated that netarsudil effectively reduces IOP, and its unique mechanism of action makes it a valuable treatment option, particularly for patients who do not achieve adequate pressure control with existing therapies.
Quick Facts: Rhokiinsa
Key Takeaways
- Rhokiinsa (netarsudil) is a Rho-kinase inhibitor eye drop that lowers intraocular pressure by increasing trabecular outflow and reducing episcleral venous pressure.
- Apply one drop in the affected eye(s) once daily in the evening – do not use more frequently as this may increase side effects without improving efficacy.
- The most common side effects are eye redness, cornea verticillata (harmless corneal deposits), and mild eye pain at the application site.
- Remove contact lenses before instilling the drops and wait at least 15 minutes before reinserting them due to the benzalkonium chloride preservative.
- Rhokiinsa offers a unique mechanism of action compared to traditional glaucoma treatments, making it particularly useful when other medications are insufficient or poorly tolerated.
What Is Rhokiinsa and What Is It Used For?
Rhokiinsa contains the active substance netarsudil, a dual-action Rho-kinase (ROCK) inhibitor and norepinephrine transporter (NET) inhibitor. It represents a relatively new pharmacological class for the treatment of elevated intraocular pressure (IOP). Unlike older glaucoma medications that primarily reduce the production of aqueous humor or increase its outflow through the uveoscleral pathway, netarsudil works predominantly on the conventional outflow pathway through the trabecular meshwork and Schlemm’s canal.
The trabecular meshwork is the primary drainage route for aqueous humor, the clear fluid that fills the front chamber of the eye. In patients with open-angle glaucoma, resistance in the trabecular meshwork increases over time, reducing the outflow of fluid and leading to a gradual rise in intraocular pressure. Netarsudil addresses this fundamental problem directly by relaxing the cells within the trabecular meshwork, allowing fluid to drain more efficiently. Additionally, netarsudil lowers episcleral venous pressure, which further contributes to IOP reduction.
Glaucoma is one of the leading causes of irreversible blindness worldwide, affecting an estimated 80 million people globally according to the World Health Organization. The most common form, primary open-angle glaucoma (POAG), is often asymptomatic in its early stages, which means many patients are unaware of the condition until significant vision loss has already occurred. Lowering intraocular pressure is currently the only proven method to slow or prevent the progression of glaucomatous damage to the optic nerve.
Ocular hypertension, a condition in which intraocular pressure is elevated above the normal range (typically above 21 mmHg) without detectable optic nerve damage or visual field loss, is a major risk factor for developing glaucoma. Treatment with IOP-lowering medications such as Rhokiinsa can reduce the risk of converting from ocular hypertension to manifest glaucoma. The Ocular Hypertension Treatment Study (OHTS) demonstrated that IOP reduction of approximately 20% can significantly lower the risk of progression to glaucoma over a five-year period.
Rhokiinsa is approved by the European Medicines Agency (EMA) and is marketed in several countries. In the United States, netarsudil is available under the trade name Rhopressa. Both formulations contain netarsudil as the active ingredient at a concentration of 200 micrograms per milliliter (0.02%). The medication is applied topically as one drop in the affected eye(s) once daily, typically in the evening, making it convenient for patients and promoting adherence to the treatment regimen.
What Should You Know Before Using Rhokiinsa?
Contraindications
Rhokiinsa must not be used if you are allergic (hypersensitive) to netarsudil or to any of the other ingredients in this medicine, including the preservative benzalkonium chloride. Allergic reactions to ophthalmic medications can manifest as increased redness, itching, swelling around the eyes, or a skin rash. If you have a known allergy to any component, discuss alternative treatment options with your ophthalmologist.
Warnings and Precautions
It is important not to use Rhokiinsa more than once daily. Using the medication more frequently does not provide additional IOP-lowering benefit and may increase the incidence and severity of side effects. Clinical studies have confirmed that once-daily evening dosing provides optimal intraocular pressure reduction throughout a 24-hour period.
Inform your doctor immediately if you experience worsening vision or increased eye pain during treatment with Rhokiinsa. These symptoms may indicate reticular epithelial corneal edema, a type of swelling in the transparent front surface of the eye (cornea). This adverse reaction has been reported in patients using netarsudil, particularly in those with certain risk factors such as a history of previous eye surgery. In most cases, the symptoms resolve after discontinuing the medication.
Rhokiinsa has not been studied in pediatric patients (under 18 years of age) and should therefore not be used in children and adolescents. The safety and efficacy of netarsudil in this age group have not been established.
Rhokiinsa contains benzalkonium chloride (approximately 150 micrograms per milliliter), which can be absorbed by soft contact lenses and may discolor them. Remove contact lenses before applying Rhokiinsa and wait at least 15 minutes before reinserting them. Benzalkonium chloride may also cause eye irritation, particularly in patients with dry eyes or corneal surface disorders. If you experience abnormal sensations, stinging, or pain in the eye after use, contact your doctor.
Pregnancy and Breastfeeding
If you are pregnant or breastfeeding, think you may be pregnant, or are planning to have a baby, consult your doctor or pharmacist before using Rhokiinsa. There are no adequate and well-controlled studies of netarsudil in pregnant women. Animal reproductive studies have provided limited information about the potential risk to the developing fetus. As a precautionary measure, Rhokiinsa should not be used during pregnancy unless your doctor considers it clearly necessary and the potential benefit outweighs the potential risk.
It is not known whether netarsudil or its metabolites are excreted in human breast milk. Since many drugs are excreted in human milk, a risk to the breastfed infant cannot be excluded. Your doctor will help you decide whether to discontinue breastfeeding or to discontinue Rhokiinsa therapy, taking into account the benefit of breastfeeding for the child and the benefit of therapy for the mother.
Driving and Using Machines
Rhokiinsa has a negligible effect on the ability to drive and use machines. However, you may experience temporary blurred or abnormal vision immediately after instilling the eye drops. Do not drive or operate machinery until your vision has cleared. This transient visual disturbance typically resolves within a few minutes of application.
How Does Rhokiinsa Interact with Other Drugs?
Because Rhokiinsa is applied topically to the eye as a drop, its systemic absorption is minimal. This means that the amount of netarsudil that reaches the general circulation is very low, reducing the likelihood of interactions with oral or injectable medications. Formal pharmacokinetic drug interaction studies have not identified clinically significant systemic interactions.
However, when using Rhokiinsa in combination with other topical ophthalmic medications, certain precautions should be observed. If you are using other eye drops in addition to Rhokiinsa, apply the other eye drops first and wait at least 5 minutes before instilling Rhokiinsa. This interval is recommended due to the vasodilatory (blood vessel-widening) properties of netarsudil, which could potentially affect the absorption of other ophthalmic medications if applied too closely together. If you also use eye ointments, these should always be applied last, after all eye drop medications.
| Drug / Class | Interaction Type | Clinical Guidance |
|---|---|---|
| Other glaucoma eye drops (prostaglandin analogues, beta-blockers, alpha-agonists, CAIs) | Additive IOP-lowering effect | Can be used together. Apply other drops first, wait 5 minutes, then apply Rhokiinsa last. Use Rhokiinsa in the evening. |
| Eye ointments (e.g., lubricant ointments) | Potential reduced absorption | Apply ointments last, after all eye drop medications have been instilled. |
| Systemic medications (oral, injectable) | No clinically significant interactions identified | Low systemic absorption of netarsudil makes systemic drug interactions unlikely. No dose adjustment required. |
| Soft contact lenses | Absorption of preservative (benzalkonium chloride) | Remove lenses before instilling drops. Wait at least 15 minutes before reinserting. |
Always inform your doctor or pharmacist about all medications you are currently using, have recently used, or might use in the future, including over-the-counter products and dietary supplements. While systemic interactions are unlikely, your healthcare provider can assess your complete medication profile and provide personalized guidance.
What Is the Correct Dosage of Rhokiinsa?
Always use Rhokiinsa exactly as your doctor or pharmacist has told you. If you are not sure, check with your doctor or pharmacist. The medication is for ocular use only (in the eye) and must not be swallowed or injected.
Adults
Standard Adult Dose
One drop of Rhokiinsa 200 micrograms/mL in the affected eye(s), once daily in the evening. Use at approximately the same time each day for consistent intraocular pressure control. The dose is the same regardless of whether one or both eyes are being treated.
Children and Adolescents
Pediatric Use
Rhokiinsa should not be used in children and adolescents under 18 years of age, as its safety and efficacy have not been studied in this population.
Elderly
Elderly Patients
No dose adjustment is necessary for elderly patients. The same dose (one drop once daily in the evening) applies regardless of age. Glaucoma is more prevalent in older adults, and clinical trials included a substantial proportion of elderly participants, confirming the safety and efficacy profile in this age group.
How to Apply Rhokiinsa Eye Drops
Correct application technique is essential for the medication to work effectively and to minimize the risk of contamination or side effects. Follow these steps carefully:
- Wash your hands thoroughly before handling the eye drop bottle.
- Remove contact lenses if you wear them (see contact lens information above).
- Unscrew the cap and place it on a clean surface. Do not touch the dropper tip with your fingers when opening or closing the bottle.
- Hold the bottle upside down between your thumb and fingers, pointing the dropper tip toward your eye.
- Tilt your head back and pull your lower eyelid down gently with a clean finger to create a small pocket between the eyelid and your eye.
- Squeeze gently to release one drop into the pocket. Do not let the dropper tip touch your eye, eyelid, surrounding areas, or any other surface.
- Close your eye and press gently on the inner corner of the eye (near the nose) for 1–2 minutes to minimize systemic absorption.
- If treating both eyes, repeat the process for the other eye while the bottle is still open.
- Replace the cap immediately after use.
If you miss the eye with the drop, try again. Only one drop per eye should be applied each time.
Missed Dose
If you forget to use Rhokiinsa at your usual time, continue with the next scheduled dose as planned. Do not use a double dose to make up for a forgotten dose. Skipping a single dose is unlikely to cause a significant long-term increase in intraocular pressure, but consistent daily use is important for maintaining optimal pressure control.
Overdose
If you accidentally use too many drops or if the medication is accidentally swallowed, rinse the eye with lukewarm water. Do not apply more drops until it is time for your next scheduled dose. If you have any concerns about overuse, contact your doctor, pharmacist, or local poison control center for advice. Topical ocular overdose is unlikely to cause serious systemic effects due to the small volume and low systemic absorption of the medication.
Do not stop using Rhokiinsa without first talking to your doctor. If you discontinue treatment, the pressure in your eye will no longer be controlled, which may lead to progressive optic nerve damage and irreversible vision loss. If you experience side effects or have concerns about the medication, discuss these with your doctor rather than stopping on your own.
What Are the Side Effects of Rhokiinsa?
Like all medicines, Rhokiinsa can cause side effects, although not everybody gets them. The following non-serious side effects have been observed during clinical trials and post-marketing surveillance. Most adverse reactions are ocular (affecting the eye) and tend to be mild to moderate in severity. Many of these effects diminish with continued use or resolve upon discontinuation of the medication.
Very Common
- Eye redness (conjunctival hyperemia)
- Cornea verticillata (small whorl-like deposits on the front surface of the eye – generally harmless and reversible upon stopping treatment)
- Pain at the application site
Common
- Eye infection or inflammation (conjunctivitis, punctate keratitis)
- Dry eyes or small defects in the tear film on the eye surface
- Eye inflammation caused by allergic reaction or prominent blood vessels
- Eye discharge; watery eyes (lacrimation)
- Eye pain; gritty or foreign body sensation in the eye
- General eye redness shortly after instilling the drops; pinpoint or patchy redness
- Itchy eyelids; swelling around the eye
- Clouding of the eye; slightly reduced vision; light sensitivity; blurred vision
- Headache
Uncommon
- Increased intraocular pressure
- Inflammation of the iris (iritis); swollen iris; small colored spots on the eye surface
- Eyelash growth; loss of eyelashes (madaros)
- Dry eyelids; abnormal outward turning of the lower eyelid; dry eyes due to meibomian gland dysfunction; crusting on the eyelids
- Diabetic retinopathy
- Conjunctivochalasis (loose conjunctival folds)
- Blindness; blurred vision; double vision; halo effect (rings around lights); cataracts
- Eye allergy; glassy eyes; fatigue
- Increased allergic symptoms; dizziness
- Nasal discomfort and pain
- Skin redness or itching; skin rash; cartilage inflammation; tingling of the skin
Not Known
- Reticular epithelial corneal edema (swelling in the transparent front surface of the eye – symptoms include worsening vision and eye pain; usually resolves after stopping the medication)
Cornea Verticillata – What You Should Know
Cornea verticillata is one of the most distinctive side effects of Rhokiinsa and other ROCK inhibitor eye drops. It refers to the formation of tiny, golden-brown or grey whorl-shaped deposits on the surface of the cornea. These deposits are composed of phospholipids and are visible upon slit-lamp examination by an ophthalmologist. In most patients, cornea verticillata does not cause any noticeable visual symptoms and does not affect visual acuity. The deposits are reversible and typically disappear within a few months after discontinuing the medication.
Your ophthalmologist will monitor for cornea verticillata during routine follow-up appointments. If you notice any changes in your vision, inform your doctor, but do not stop treatment without medical advice, as the risk of uncontrolled glaucoma generally outweighs the impact of this benign finding.
When to Seek Medical Attention
Contact your doctor promptly if you experience any of the following:
- Sudden or significant worsening of vision
- Severe eye pain that does not resolve within a few minutes of application
- Signs of a serious allergic reaction (severe redness, swelling of the face or eyelids, difficulty breathing)
- Any new or worsening eye symptoms that concern you
You are encouraged to report suspected side effects to your national medicines regulatory authority. Reporting helps to continuously monitor the benefit-risk balance of the medication and contributes to drug safety for all patients.
How Should You Store Rhokiinsa?
Keep Rhokiinsa out of the sight and reach of children. Do not use this medicine after the expiry date stated on the carton and bottle label (“EXP”). The expiry date refers to the last day of that month.
- Unopened bottles: Store in the refrigerator at 2–8°C.
- After first opening: Store at or below 25°C (room temperature).
- Discard after: 4 weeks from the date of first opening, even if there is solution remaining in the bottle.
Discarding the bottle 4 weeks after opening is essential to prevent microbial contamination, as the preservative effectiveness diminishes over time once the bottle is opened. Write the date of first opening on the bottle or carton to help you remember when to dispose of it.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures will help to protect the environment.
What Does Rhokiinsa Contain?
Each milliliter of Rhokiinsa eye drop solution contains 200 micrograms of netarsudil (as netarsudil mesylate). Netarsudil mesylate is the salt form of the active substance that provides stability and solubility in the aqueous formulation.
Active Ingredient
| Ingredient | Amount per mL | Role |
|---|---|---|
| Netarsudil (as mesylate) | 200 micrograms | Active substance – Rho-kinase inhibitor |
Inactive Ingredients (Excipients)
| Ingredient | Function |
|---|---|
| Benzalkonium chloride | Preservative (approximately 150 micrograms per mL) |
| Mannitol | Tonicity agent (adjusts osmolarity) |
| Boric acid | Buffer (maintains pH stability) |
| Sodium hydroxide | pH adjustment |
| Water for injections | Vehicle (solvent) |
Packaging
Rhokiinsa 200 micrograms/mL eye drops solution is a clear liquid supplied in a plastic bottle. Each bottle contains 2.5 mL of solution and comes with a screw cap. Each carton contains one bottle. The solution should appear clear and free of particles before each use. Do not use the product if it appears discolored or contains visible particles.
Marketing Authorization Holder
Santen Oy, Niittyhaankatu 20, 33720 Tampere, Finland. Santen is a specialized pharmaceutical company focused on ophthalmology, with a global presence in the development and commercialization of ophthalmic therapies. For any questions about this medicine, contact your local Santen representative or pharmacist.
Frequently Asked Questions About Rhokiinsa
Rhokiinsa (netarsudil) works through a fundamentally different mechanism compared to traditional glaucoma medications. Prostaglandin analogues such as latanoprost and bimatoprost lower IOP by increasing uveoscleral outflow. Beta-blockers like timolol reduce aqueous humor production. Alpha-agonists such as brimonidine both decrease production and increase uveoscleral outflow. In contrast, netarsudil is a Rho-kinase (ROCK) inhibitor that primarily enhances conventional outflow through the trabecular meshwork – the eye’s main drainage pathway – and reduces episcleral venous pressure. This unique mechanism makes Rhokiinsa a valuable addition to the glaucoma treatment armamentarium, especially for patients who need additional IOP lowering beyond what conventional agents provide, or who cannot tolerate other classes of eye drops.
Cornea verticillata is a very common side effect of Rhokiinsa, occurring in more than 1 in 10 users. It involves the formation of small whorl-shaped deposits (made up of phospholipids) on the surface of the cornea, visible during a slit-lamp examination. In the vast majority of cases, cornea verticillata does not affect visual acuity or cause any noticeable visual symptoms. The deposits are benign and fully reversible – they typically disappear within a few months after stopping the medication. Your ophthalmologist will monitor for this finding during regular checkups, but it is generally not a reason to discontinue treatment unless accompanied by other concerning eye symptoms.
Yes, Rhokiinsa can be used in combination with other glaucoma eye drops to achieve additional IOP reduction when monotherapy is insufficient. In clinical practice, it is commonly used alongside prostaglandin analogues, beta-blockers, alpha-agonists, or carbonic anhydrase inhibitors. When using multiple eye drops, apply the other medications first and wait at least 5 minutes before instilling Rhokiinsa. This timing is important due to the vasodilatory properties of netarsudil. Eye ointments should always be applied last. Always follow your doctor’s instructions regarding the timing and sequence of your eye drop medications.
Rhokiinsa is recommended for once-daily evening dosing based on the results of clinical studies. Evening administration was shown to provide consistent intraocular pressure lowering throughout the 24-hour dosing period. Additionally, the most common side effect – eye redness (conjunctival hyperemia) – is more tolerable when it occurs during the evening and overnight hours, as it typically subsides by the following morning. Using the drops at a consistent time each evening also helps establish a routine that promotes adherence to the treatment regimen.
Rhokiinsa and Rhopressa both contain the same active ingredient, netarsudil, at the same concentration (200 micrograms/mL or 0.02%). Rhokiinsa is the trade name used in the European Union, marketed by Santen Oy, while Rhopressa is the trade name used in the United States, marketed by Aerie Pharmaceuticals (now part of Alcon). Both are indicated for the reduction of elevated intraocular pressure in adults with open-angle glaucoma or ocular hypertension, and both are used as one drop once daily in the evening. The clinical efficacy and safety profile are essentially the same.
In clinical trials, Rhokiinsa (netarsudil 0.02%) demonstrated clinically meaningful reductions in intraocular pressure. In pivotal studies (MERCURY-1 and MERCURY-2), netarsudil reduced IOP by approximately 3–5 mmHg from baseline when used as monotherapy. While the absolute IOP reduction may be somewhat less than that achieved with prostaglandin analogues (which typically lower IOP by 6–8 mmHg), netarsudil’s unique mechanism of action targeting the trabecular meshwork makes it particularly valuable as an adjunctive therapy. When added to other glaucoma medications, it provides additional IOP lowering through a complementary pathway. Your ophthalmologist will assess whether Rhokiinsa provides adequate IOP control for your individual situation.
References
- European Medicines Agency (EMA). Rhokiinsa (netarsudil) – Summary of Product Characteristics. Last updated 2025. Available at: EMA Rhokiinsa EPAR.
- U.S. Food and Drug Administration (FDA). Rhopressa (netarsudil ophthalmic solution) 0.02% – Prescribing Information. Aerie Pharmaceuticals / Alcon. Revised 2024.
- Serle JB, Katz LJ, McLaurin E, et al. Two Phase 3 Clinical Trials Comparing the Safety and Efficacy of Netarsudil to Timolol in Patients With Elevated Intraocular Pressure: Rho Kinase Elevated IOP Treatment Trial 1 and 2 (ROCKET-1 and ROCKET-2). Am J Ophthalmol. 2018;186:116–127. doi:10.1016/j.ajo.2017.11.019.
- Kahook MY, Serle JB, Mah FS, et al. Long-term Safety and Ocular Hypotensive Efficacy Evaluation of Netarsudil Ophthalmic Solution: Rho Kinase Elevated IOP Treatment Trial (ROCKET-4). Am J Ophthalmol. 2019;200:130–137. doi:10.1016/j.ajo.2019.01.003.
- European Glaucoma Society (EGS). Terminology and Guidelines for Glaucoma, 5th Edition. PubliComm, Savona, Italy. 2020.
- American Academy of Ophthalmology (AAO). Primary Open-Angle Glaucoma Preferred Practice Pattern. 2024.
- Kass MA, Heuer DK, Higginbotham EJ, et al. The Ocular Hypertension Treatment Study: A Randomized Trial Determines That Topical Ocular Hypotensive Medication Delays or Prevents the Onset of Primary Open-Angle Glaucoma. Arch Ophthalmol. 2002;120(6):701–713. doi:10.1001/archopht.120.6.701.
- Tham YC, Li X, Wong TY, et al. Global Prevalence of Glaucoma and Projections of Glaucoma Burden through 2040: A Systematic Review and Meta-Analysis. Ophthalmology. 2014;121(11):2081–2090. doi:10.1016/j.ophtha.2014.05.013.
- World Health Organization (WHO). Blindness and Vision Impairment. Fact Sheet. 2023. Available at: WHO Blindness and Vision Impairment.
- British National Formulary (BNF). Netarsudil. National Institute for Health and Care Excellence (NICE). 2025.
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