Dilate1%

Dilate is an anticholinergic (antimuscarinic) ophthalmic agent used to produce short-acting mydriasis (pupil dilation) and cycloplegia (temporary paralysis of accommodation) for diagnostic eye examinations.

• Established/FDA-approved use: Pupil dilation (mydriasis) for routine ophthalmoscopic examination of the fundus and posterior segment.
• Established/FDA-approved use: Cycloplegia to facilitate accurate cycloplegic refraction, particularly in children, to measure true refractive error without interference from accommodation.
• Adjunct use: Often combined with a sympathomimetic agent such as phenylephrine to achieve faster onset and more complete mydriasis before ophthalmic examination, laser procedures, or minor diagnostic/surgical eye procedures.

Dilate is not intended for the treatment of any ocular disease; it is a diagnostic aid only.

Each mL of ophthalmic solution contains Tropicamide 0.5% w/v or 1% w/v, with benzalkonium chloride commonly used as a preservative in multi-dose preparations, along with other pharmaceutically inert excipients to adjust tonicity and pH.

Dilate is a synthetic anticholinergic (antimuscarinic) compound formulated as a sterile ophthalmic solution for topical use in the eye. It produces rapid-onset, relatively short-duration mydriasis and cycloplegia, making it one of the most commonly used diagnostic mydriatic/cycloplegic agents in routine eye examinations, in contrast to longer-acting agents such as atropine or homatropine.

Dilate belongs to the anticholinergic (antimuscarinic) class of ophthalmic diagnostic agents, specifically classified as a mydriatic and cycloplegic agent.

Tropicamide is a competitive antagonist at muscarinic (M3) acetylcholine receptors located in the iris sphincter and ciliary body of the eye. By blocking the response of the sphincter muscle to acetylcholine, Tropicamide allows the iris dilator muscle to act unopposed, producing mydriasis (pupil dilation). Simultaneous blockade of muscarinic receptors in the ciliary muscle relaxes accommodation, producing cycloplegia.

Onset of mydriasis typically occurs within 15-20 minutes of instillation, with maximal effect at 20-40 minutes and recovery of normal pupil size within about 6 hours. The cycloplegic effect develops similarly but is generally less complete than with atropine or cyclopentolate and also resolves within approximately 6 hours, which is why Tropicamide is preferred for brief diagnostic procedures rather than prolonged therapeutic cycloplegia.

Dilate ophthalmic solution is for topical ocular use only and must never be injected or taken by mouth.

• Wash hands before use.
• Tilt the head back, gently pull down the lower eyelid to form a small pocket, and instill the prescribed number of drops without letting the dropper tip touch the eye, eyelid, or any surface.
• Apply gentle pressure over the inner corner of the eye (punctal occlusion) for 1-2 minutes after instillation to reduce systemic absorption, especially in infants and young children.
• Close the eye gently for 1-2 minutes after instillation.
• If more than one ophthalmic drop is prescribed, wait at least 5 minutes between different eye drop products.

Dilate has a low potential for clinically significant drug interactions because of its topical ophthalmic route and short duration of systemic exposure. Notable points include:

• Other anticholinergic/antimuscarinic agents (e.g., oral antihistamines, tricyclic antidepressants, atropine-type drugs): additive systemic anticholinergic effects (dry mouth, tachycardia, flushing, urinary retention) may occur if significant systemic absorption of Dilate takes place, particularly in infants and young children.
• Other mydriatic/cycloplegic ophthalmic agents (e.g., phenylephrine, cyclopentolate): commonly and intentionally used together with Dilate to enhance mydriasis; effects are additive rather than adverse, but combined use increases the risk of systemic anticholinergic/sympathomimetic effects, so appropriate spacing and monitoring are advised, particularly in infants.

Ocular side effects are most common and are usually transient:

• Transient stinging or burning sensation immediately after instillation.
• Blurred vision and photophobia (light sensitivity) lasting several hours while the pupil remains dilated.
• Increased intraocular pressure, particularly in individuals predisposed to angle-closure (see Contraindications).
• Superficial punctate keratitis (uncommon).

Systemic anticholinergic effects are uncommon with recommended ophthalmic dosing of Dilate but may occur, particularly in infants, young children, and with excessive or repeated dosing:

• Dry mouth, flushed/dry skin, tachycardia (fast heart rate).
• Fever, especially in children.
• Central nervous system disturbances such as restlessness, disorientation, ataxia, or, rarely, hallucinations/psychotic-like reactions, mainly reported in children.
• Rarely, in premature and low-birth-weight infants, cardiorespiratory disturbances (apnea) and feeding intolerance/gastrointestinal dysfunction have been reported with repeated dosing.

There is limited controlled human safety data for Dilate use in pregnancy. Because ophthalmic instillation results in only minimal systemic absorption, systemic risk is generally considered low; nevertheless, Dilate should be used during pregnancy only if clearly needed and the potential benefit justifies the potential risk to the fetus. Use should be under the direction of a physician.

It is not known whether Dilate is excreted in human breast milk in clinically significant amounts. Caution is advised when Dilate is administered to a breastfeeding woman, and a physician should be consulted before use.

Dilate causes temporary blurred vision and increased sensitivity to light. Patients should not drive, operate machinery, or perform other hazardous tasks until vision has returned to normal, generally within a few hours.

Use Dilate with caution in infants and young children, who are more susceptible to systemic anticholinergic effects (see Side Effects); punctal occlusion (applying gentle pressure at the inner corner of the eye after instillation) is recommended to reduce systemic absorption, particularly in this population.

Dilate may precipitate acute angle-closure glaucoma in susceptible individuals (see Contraindications); patients should be assessed for narrow anterior chamber angles before use and warned to seek urgent medical attention for eye pain, redness, or nausea/vomiting after dilation.

Use caution in patients with Down syndrome, spastic paralysis, or brain damage, who may show heightened sensitivity to anticholinergic effects. Sterile technique should be used, and multi-dose bottles of Dilate should not be shared between patients to avoid cross-contamination.

Accidental ocular overdose or accidental oral ingestion of Dilate solution may cause systemic anticholinergic toxicity, including dry mouth, flushed skin, fever, rapid heartbeat, blurred vision, urinary retention, restlessness, confusion, hallucinations, or, in severe cases, seizures or cardiorespiratory depression, especially in young children. If overdose or accidental ingestion of Dilate is suspected, seek immediate medical attention or contact a poison control center/emergency services right away; do not attempt home treatment.

Store at room temperature (below 30°C), protected from light and moisture. Keep the container tightly closed when not in use, and keep out of reach of children. Discard any unused solution per the expiry/discard-after-opening period stated on the label, and discontinue use if the solution becomes discolored or cloudy.

Pediatric use: Dilate is commonly used in infants and children for diagnostic pupil dilation and cycloplegic refraction. Infants, particularly premature and low-birth-weight infants, are more susceptible to systemic anticholinergic effects and should receive the lowest effective dose of Dilate with punctal occlusion; feeding may be withheld for a short period after instillation in very young infants per institutional protocol, since gastrointestinal dysfunction has been reported.

Elderly: No specific dose adjustment of Dilate is generally required; elderly patients, particularly those with shallow anterior chambers, should be evaluated for narrow-angle glaucoma risk before dilation (see Contraindications).

Renal/Hepatic impairment: No specific dose adjustment is established for ophthalmic Dilate given its minimal systemic absorption; formal studies in these populations are lacking.

Dilate is used as a single diagnostic dose (with a possible repeat dose after 5 minutes) rather than as ongoing therapy. Its mydriatic and cycloplegic effects last approximately 6 hours, after which pupil size and accommodation typically return to normal. Dilate is not intended for repeated or long-term use outside of individual diagnostic examinations, except as directed by an eye-care professional for specific clinical circumstances.

Anticholinergic (antimuscarinic) ophthalmic mydriatic and cycloplegic agent.

Tropicamide competitively blocks muscarinic acetylcholine receptors in the iris sphincter and ciliary muscle, preventing the pupillary constrictor response to acetylcholine and relaxing the ciliary muscle. This unopposed action of the iris dilator muscle produces mydriasis, while ciliary muscle relaxation produces cycloplegia (loss of accommodation).

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Dilate is widely used in the pediatric population for diagnostic mydriasis and cycloplegic refraction, including in infants. Safety and effectiveness have been established for its use as a short-acting diagnostic mydriatic/cycloplegic in children under appropriate professional supervision; however, infants and young children are more susceptible to systemic anticholinergic adverse effects, and the lowest effective concentration/dose of Dilate with punctal occlusion is recommended. Caution is advised in premature and low-birth-weight infants, in whom cardiorespiratory and gastrointestinal disturbances have rarely been reported with repeated dosing.