Cyclopentolate Eye Drops 

Below is a detailed, informative article on Cyclopentolate eye drops, including the formulation sold by Zencus Pharma (branded as Cyclozen Eye Drops). This is for educational purposes only — always rely on a qualified ophthalmologist for specific medical advice.

What Is Cyclopentolate?

Cyclopentolate is a mydriatic–cycloplegic agent used in ophthalmology. It works by blocking muscarinic (cholinergic) receptors in the eye, thereby:

• Causing mydriasis (dilation of the pupil)
• Producing cycloplegia (paralysis of accommodation — i.e. paralyzing the ciliary muscle)

These effects help eye doctors examine the internal structures of the eye and measure refractive error without the interference of accommodation.

Because cyclopentolate has a shorter duration of action than atropine, it is often preferred for routine diagnostic procedures.

Cyclozen Eye Drops — Zencus Pharma’s Formulation

Zencus Pharma, based in Chandigarh, markets a version of cyclopentolate as “Cyclozen Eye Drops (Cyclopentolate Ophthalmic Solution IP).

• Salt / Composition: Cyclopentolate 0.5% w/v
• Indications: Used for pupillary dilation in eye examinations, treatment of uveitis, and reducing redness/swelling after cataract surgery.
• Storage & Handling: Store below about 30 °C; keep the dropper tip clean; for external ophthalmic use only.
• Precautions: May increase photosensitivity, cause temporary blurred vision, and make driving unsafe immediately after use.

Cyclozen is a branded product from Zencus Pharma marketed for ophthalmic uses.

Uses / Indications

Cyclopentolate eye drops are used in various ophthalmic settings. Common indications include:

1. Eye examinations & refraction testing
   To dilate pupils and paralyze accommodation, allowing the ophthalmologist or optometrist to examine the retina, optic nerve, and internal structures without interference from focusing.
2. Uveitis / Inflammatory eye diseases
   Helps reduce pain by keeping the pupil dilated (preventing posterior synechiae) and relaxing the ciliary muscle.
3. Postoperative ocular inflammation
   After cataract surgery or other intraocular procedures, cyclopentolate may be used to reduce ciliary spasm, pain, and control inflammation.
4. Other diagnostic or surgical procedures
   In some cases, for ocular diagnostics or minor treatments requiring a dilated pupil.

How It Works (Mechanism of Action)

Cyclopentolate is an anticholinergic (antimuscarinic) drug applied topically to the eye. As such, it:

• Blocks the action of acetylcholine on muscarinic receptors in the iris sphincter and the ciliary body
• This inhibition results in relaxation of the sphincter muscle → pupil dilation (mydriasis)
• It also leads to paralysis of the ciliary muscle → cycloplegia, inhibiting the eye’s ability to accommodate (focus for near objects)

Because its effect is milder and more transient than atropine, it is widely used for routine eye workups.

Dosage & Administration

The exact dose and strength depend on the patient’s age, eye pigmentation, and clinical needs. The following are general guidelines (must be tailored by the physician):

• In many formulations, 1% solution is common (i.e. 10 mg/mL)
• Some formulations (like Zencus’s Cyclozen) use 0.5% strength for less intense or pediatric use.
• Typical adult dose: 1 or 2 drops instilled into the eye(s). A repeat dose after 5–10 minutes may be given if needed.
• For children, infants: Use lower strengths; caution is needed due to risk of systemic absorption.
• After instillation, compressing (applying pressure on) the nasolacrimal sac (corner of the eye near the nose) for 2–3 minutes helps minimize systemic absorption.
• Wait 5–10 minutes between instilling multiple eye drops in the same eye to reduce dilution.

Onset & Duration:

• Maximum cycloplegia generally occurs within 25 to 75 minutes after instillation.
• Recovery (return of accommodation) occurs often within 6 to 24 hours, though mydriasis may persist longer.
• In some individuals, full recovery of pupil size may take several days.

Side Effects & Risks

While cyclopentolate is well tolerated when used appropriately, it may cause both ocular and systemic side effects, especially in vulnerable populations (infants, children, elderly).

Ocular / Local Side Effects

• Burning, stinging or irritation upon instillation
• Blurred vision (especially for near objects)
• Photophobia (increased sensitivity to light)Eye redness, conjunctival hyperemia
• Increased intraocular pressure (especially in predisposed individuals)
• Synechiae, or exacerbation of angle-closure glaucoma risk

Systemic / Extraocular Side Effects

Although the eye is the intended site, some systemic absorption may occur, especially in infants or when higher concentrations are used. Reported effects include:

• Central nervous system effects: restlessness, hallucinations, disorientation, ataxia, incoherent speech, especially in children.
• Tachycardia, flushing, dryness of mouth, urinary retention (anticholinergic effects)
• Gastrointestinal effects: reduced motility, discomfort
• Feeding intolerance in infants; necrotizing enterocolitis has been reported in preterm infants in rare cases.

Contraindications / Warnings:

• Hypersensitivity to cyclopentolate or any excipients
• Angle-closure glaucoma or narrow anterior chamber angles
• Caution in infants, children, elderly, those with central nervous system diseases, Down syndrome
• Use in pregnancy or breastfeeding only if clearly needed and under medical supervision

If serious adverse effects (such as confusion, hallucinations, severe discomfort) arise, stop use and seek medical attention immediately.

Precautions & Patient Instructions

• Do not touch the dropper tip to the eye, fingers, or any surface to avoid contamination.
• After instilling the drop, press gently on the inner corner (nasolacrimal duct) for 1–2 minutes to reduce systemic absorption.
• Avoid driving or operating machinery until vision returns to normal and sensitivity to light subsides.
• Wear sunglasses in bright light conditions after instillation.
• Inform your physician of any eye conditions (glaucoma, intraocular pressure issues), neurological conditions, or systemic diseases.
• If used in children, monitor closely for behavioral or neurological changes.
• Do not use expired solution; discard after recommended duration.

Drug Interactions

Cyclopentolate may interact with other ocular and systemic drugs:

• Cholinergic / miotic agents (e.g. pilocarpine, cholinesterase inhibitors): effects may be antagonistic
• Other anticholinergic drugs may have additive systemic effects
• In ocular therapy, timing matters — separate instillation of other eye drops by 5–10 minutes to avoid dilution/interference

Always disclose all medications (including over-the-counter or herbal supplements) to your ophthalmologist before use.

Summary & Key Points

• Cyclopentolate is a mydriatic–cycloplegic eye drop used primarily for pupil dilation and paralysis of accommodation during eye exams and certain ocular conditions.
• Zencus Pharma’s branded version is Cyclozen Eye Drops (Cyclopentolate Ophthalmic Solution IP), commonly in 0.5% strength.
• The effects typically onset within 30–75 minutes; recovery may take 6–24 hours or longer for pupil size.
• Common side effects are ocular irritation, blurred vision, light sensitivity; systemic anticholinergic effects are rare but possible, especially in children.
• Proper administration techniques and precautions are vital to minimize risks.