C-Nac Eye Drop

About this Medicine C-Nac Eye Drops, containing Carboxymethylcellulose (3 mg/ml), Glycerin (10 mg/ml), and N-acetylcarnosine (10 mg/ml), are indicated for ocular surface disorders associated with oxidative stress, lens changes, and tear film instability. The formulation is sterile and intended for topical ophthalmic use. The primary indication is the management and possible slowing of early cataract progression. Cataracts involve clouding of the natural lens due to protein oxidation and aggregation related to ageing, diabetes, UV exposure, and oxidative stress. N-acetylcarnosine acts as an antioxidant that helps stabilise lens proteins and reduce oxidative damage. C-Nac is also indicated for chronic dry eye syndrome (keratoconjunctivitis sicca). Carboxymethylcellulose functions as a tear substitute and lubricant, helping relieve irritation, foreign body sensation, burning, and discomfort caused by reduced tear production or excessive tear evaporation, while glycerin supports surface hydration. It may be used in eye fatigue and visual stress, particularly in individuals exposed to prolonged screen use or polluted environments, where combined lubrication and antioxidant protection help soothe the ocular surface and reduce strain. Additional supportive indications include pterygium, contact lens discomfort related to oxidative irritation, mild age-related ocular changes where antioxidant protection may support ocular health, and post-surgical eye hydration under medical advice. C-Nac is not intended for treating infections, glaucoma, or acute inflammatory eye conditions and should be used only under the guidance of an eye care professional. Uses and Benefits C-Nac Eye Drops provide antioxidant protection, lubrication, and tear film stabilisation through the combined action of N-acetylcarnosine, carboxymethylcellulose, and glycerin, supporting both ocular surface health and lens protection. N-acetylcarnosine helps neutralise free radicals and reduce oxidative damage to lens proteins, which may delay cataract progression in early stages. Although it does not replace surgical treatment, regular use may help preserve lens clarity for longer periods. Carboxymethylcellulose and glycerin improve ocular surface hydration by mimicking natural tears and retaining moisture, providing relief from dryness, irritation, burning, and foreign body sensation caused by ageing, screen exposure, air conditioning, or systemic conditions such as Sjögren’s syndrome. The formulation may reduce eye fatigue and discomfort associated with prolonged screen exposure, pollution, and contact lens use, while also improving tear film stability, which is essential for clear vision and protection against evaporation-related dryness. C-Nac may be used as adjunctive support in age-related ocular conditions and during post-surgical recovery under medical supervision, helping maintain hydration and surface protection. The oxychloro complex preservative breaks down into natural tear components after instillation, providing antimicrobial safety with better tolerability than harsh preservatives such as benzalkonium chloride. Side Effects C-Nac Eye Drops are generally well tolerated, and most side effects are mild and temporary. Common effects include mild stinging, burning, itching, foreign body sensation, increased tearing, redness, dryness or gritty feeling, and temporary blurred vision immediately after application due to the viscosity of the drops. Patients should avoid driving or operating machinery until vision becomes clear. Some users may experience ocular discomfort or sensitivity to light (photophobia), especially if the eyes are already irritated. These symptoms usually improve as the eyes adapt to the formulation or after dose adjustment under medical advice. Rarely, allergic reactions may occur, presenting as severe itching, eyelid swelling, intense redness, or watery discharge. In such cases, the medicine should be discontinued and medical attention sought immediately. Risk factors that may increase side effects include using expired drops, contamination of the dropper tip, improper storage (exposure to heat or light), or using the drops with contact lenses without waiting the advised 15-minute gap before reinsertion. Patients should seek medical help if they experience eye pain, sudden vision changes, severe swelling around the eyes, yellow or green discharge, or symptoms that persist or worsen after several days of use. Proper hygiene, correct technique, and adherence to prescribed dosing can significantly reduce the risk of adverse effects. Precautions C-Nac Eye Drops should be used only under medical supervision, especially for long-term conditions such as early cataracts or chronic dry eye. Patients should not self-medicate or continue prolonged use without periodic reassessment by an eye care professional. Contact lenses must be removed before instillation and reinserted only after at least 15 minutes, as even mild preservatives such as oxychloro complex may interact with soft lenses. The dropper tip should never touch the eye, eyelids, fingers, or any surface to prevent contamination and infection. Use in children should be only under paediatric ophthalmologic guidance, while elderly patients should be assessed for coexisting eye conditions and concurrent medications. Use during pregnancy or breastfeeding should be only if clearly needed and recommended by a doctor, as safety data for N-acetyl-carnosine and other ingredients are limited. Do not use the drops in infected or injured eyes or after recent eye surgery unless specifically advised by a doctor. If using multiple eye medications, maintain at least a 15-minute gap between drops and follow the sequence prescribed to avoid dilution or interaction. Always check the expiry date, discard the bottle after the recommended period (usually 28 days after opening), store in a cool and dry place away from sunlight, and keep out of reach of children. Do not change dose or frequency without medical advice, and discontinue use if allergy symptoms such as swelling, itching, or redness occur. Expert Advice Always consult a qualified medical professional before starting this medicine. The usual dose of C-Nac Eye Drops is 1 to 2 drops in the affected eye(s) twice daily, or as directed by your eye specialist. Do not exceed the recommended dose unless specifically instructed by your doctor. Consistent and long-term use may be required for cataract support or dry eye maintenance. For correct use, wash your hands thoroughly before application. Tilt your head slightly, pull down the lower eyelid to form a pocket, and instil one drop into the eye. Close your eyes and press gently on the inner corner near the nose for 1 to 2 minutes to reduce drainage and systemic absorption. Avoid blinking excessively or rubbing the eyes after use. Who can use: Adults with early-stage cataracts, individuals with eye strain due to screen use or pollution, patients with chronic dry eye syndrome, contact lens users with an appropriate gap before and after use, and elderly individuals with age-related ocular changes. Suitability should always be confirmed by an ophthalmologist based on eye condition and medical history. Who should avoid: Children unless prescribed by a paediatric ophthalmologist, individuals allergic to any component of the drops, patients with active eye infections, injuries, or recent ocular surgery unless advised by a doctor, and pregnant or breastfeeding women unless clearly recommended after evaluation. Overdose and missed dose: Overuse may cause temporary discomfort such as redness, stinging, or watering. If excess drops are applied, rinse the eye gently with clean water. If a dose is missed, apply it when remembered unless it is almost time for the next dose. Do not double the dose. Maintain at least a 15-minute gap between C-Nac and other eye drops, apply drops before ointments, store below 25°C, discard after 28 days of opening, and attend regular follow-ups during long-term use. Can I use C-Nac Eye Drops after cataract surgery? Use only under your doctor’s advice. It may help with dryness or irritation but does not replace post-surgical care. How long should I use C-Nac to see improvement? Improvement may take weeks or months with regular use. Follow your doctor’s recommended duration. Can I refrigerate C-Nac Eye Drops to extend shelf life? No. Store at room temperature away from sunlight. Do not freeze unless specified by the manufacturer. Are there food or medicine interactions with C-Nac? Systemic interactions are unlikely as the medicine is used locally, but inform your doctor about all medicines you use. Is it safe to continue using C-Nac even if symptoms improve? Yes, if prescribed for long-term support. Do not skip doses based on symptoms alone. References & Disclaimer 1. Babizhayev MA, et al. Efficacy of N-acetylcarnosine in the treatment of cataracts. Journal of Refractive Surgery. 2002;18(6):540–. 2. 5. 3. 4. 4. Tear Film and Ocular Surface Society (TFOS) DEWS II Report. Ocular Surface. 2017;15(3):276–. 5. 2. 6. 8. 7. Martindale: The Complete Drug Reference. Pharmaceutical Press. 39th Edition. 8. British National Formulary (BNF). 9. National Centre for Biotechnology Information (NCBI). N-acetylcarnosine: antioxidant profile and ophthalmic use. Disclaimer: This information is intended for educational purposes only and should not replace medical advice from your doctor or pharmacist. Always consult a qualified healthcare provider for diagnosis and treatment options tailored to your health needs. Medical knowledge and clinical guidelines may change over time, and treatment should always be based on individual medical evaluation. Created By: Gantala Alekhya Reddy, Created At: May 19, 2025, 2:06 a.m., Approved By: Dr. Yumnam Sotirani, Registration Number: MNMC-04597