Medically Reviewed on 12/8/2022

Generic Name: cyclopentolate

Brand Names: Cyclogyl, AK-Pentolate

Drug Class: Cycloplegics/Mydriatics; Anticholinergic Agents, Ophthalmic

What is cyclopentolate, and what is it used for?

Cyclopentolate is an ophthalmic solution administered in the eye to dilate the pupils for eye examination and diagnostic purposes.

Cyclopentolate temporarily inactivates (paralyzes) the eye muscles that enable widening (mydriasis) and narrowing (miosis) of the pupils, and focusing the vision for near and far objects (accommodation). Cyclopentolate is also used off-label to relieve pain from uveitis, and inflammation of uvea, the middle layer of the eye.

Cyclopentolate is an anticholinergic agent that works by blocking the activity of acetylcholine, a chemical that nerve cells (neurons) secrete in neuromuscular junctions to make muscles contract. Cyclopentolate blocks muscarinic receptors, protein particles on muscle fibers that respond to acetylcholine signaling and initiate muscle contraction. Cyclopentolate achieves dilation of pupils (mydriasis) by:

  • Paralysis of the sphincter muscle encircling the pupil that contracts with bright light and dilates in low light
  • Paralysis of the ciliary muscle (cycloplegia) that adjusts lens shape and thickness, enabling eye accommodation


  • Do not use in patients with hypersensitivity to cyclopentolate or any of the components in the solution.
  • Advise patients to remove contact lenses before administration and wait for 15 minutes before reinsertion.
  • Do not allow the dropper tip to touch any surface, it may contaminate the solution.
  • Cyclopentolate may cause a transient burning sensation in the eye.
  • Cyclopentolate may cause a transient increase in intraocular pressure, particularly in elderly patients. Use with caution in patients with narrow-angle glaucoma, a condition with high intraocular pressure.

What should I avoid after pupil dilation?

  • Advise patients not to engage in hazardous activities while the effects of the drug are present.
  • Advise patients to protect the eyes from bright light while the pupils remain dilated.
  • Infants may have feeding intolerance after administration of ophthalmic cyclopentolate. Withhold feeding for 4 hours after administration.
  • Cyclopentolate may have central nervous system and cardiopulmonary effects, especially in young children and with the use of strong solutions. Exercise caution.


Pink Eye (Conjunctivitis) Symptoms, Causes, Treatments See Slideshow

What are the side effects of cyclopentolate?

Common side effects of cyclopentolate include:

  • Burning sensation in the eye
  • Blurred vision
  • Eye focusing difficulty (accommodation disturbance)
  • Increase in intraocular pressure
  • Light intolerance
  • Inflammation of the conjunctiva, the membrane that covers the eye whites and inner eyelid surfaces (conjunctivitis)
  • Burning sensation of the skin
  • Hypersensitivity reaction
  • Drowsiness
  • Rapid heart rate (tachycardia)
  • Hyperreactive response in Down’s syndrome children
  • Hyperactivity
  • Impairment of coordination and balance (ataxia)
  • Incoherent speech
  • Restlessness
  • Hallucination
  • Psychosis
  • Seizure

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

What are the dosages of cyclopentolate?


  • 0.5%
  • 1%
  • 2%


Mydriasis/Cycloplegia Diagnosis

  • 1-2 drops of 1% solution in the eye
  • May repeat in 5 minutes as needed
  • Cycloplegia and mydriasis may last for 24 hours
  • Use 2% in a heavily pigmented iris



  • 1-2 drops of 0.5%,1%, or 2% solution in eye
  • May repeat 5 minutes later by a second application of 0.5% or 1% solution if necessary


  • Cyclopentolate overdose in the eye can cause persistent pupil dilation for several hours, which generally resolves on its own. Ocular overdose can be treated by flushing the eyes with clean water.
  • Systemic absorption from ocular overdose can cause dilated pupils, disorientation, visual hallucination, behavior disturbances, and impairment of balance, coordination, and speech (ataxia).
  • Oral ingestion of cyclopentolate eye solution can cause dizziness, rapid heart rate (tachycardia), drowsiness, dry mouth, uncoordinated movements, and behavioral disturbances.
  • Adverse effects from systemic absorption usually resolve within a few hours. Severe systemic effects from oral overdose may be treated by inducing vomiting, performing gastric lavage, and if required, administration of physostigmine, a drug that reverses the effects of cyclopentolate.

What drugs interact with cyclopentolate?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Severe interactions of cyclopentolate include:
  • Serious interactions of cyclopentolate include:
  • Cyclopentolate has moderate interactions with at least 19 different drugs.
  • Cyclopentolate has no known mild interactions with other drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • No animal reproductive studies or adequate and well-controlled human trials have been conducted on cyclopentolate use during pregnancy. Use in pregnant women only if clearly needed.
  • It is not known if cyclopentolate is present in breast milk, however, because many drugs are excreted in breast milk, use with caution in nursing mothers.

What else should I know about cyclopentolate?

  • If you use cyclopentolate for uveitis, follow your doctor’s instructions exactly.
  • Do not allow the dropper to touch any surface when you administer the drops.
  • Do not allow the solution to touch the mouth, and wash hands thoroughly after administration.
  • Do not engage in hazardous activities like driving or operating heavy machinery while the eyes are dilated.
  • Protect your eyes from bright lights while the eyes are dilated.
  • Store cyclopentolate safely out of reach of children.
  • In case of ocular overdose, wash the eyes with water and consult with your ophthalmologist if ocular or systemic symptoms persist.
  • In case of overdose from oral ingestion, seek medical help or contact Poison Control.

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Cyclopentolate is an ophthalmic solution administered in the eye to dilate the pupils for eye examination and diagnostic purposes. Common side effects of cyclopentolate include burning sensation in the eye, blurred vision, eye focusing difficulty (accommodation disturbance), increase in intraocular pressure, light intolerance, inflammation of the conjunctiva, burning sensation of the skin, hypersensitivity reaction, drowsiness, rapid heart rate (tachycardia), hyperreactive response in Down’s syndrome children, hyperactivity, impairment of coordination and balance (ataxia), incoherent speech, restlessness, hallucination, psychosis, and seizure.

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 12/8/2022