In short
Cyclopentolate hydrochloride is an anticholinergic medicine used as eye drops to enlarge the pupil and temporarily paralyse the lens of the eye. It is already authorised as a medicine in both the United States and the United Kingdom. In one European clinical trial, it is being used as part of the standard care during eye screening for retinopathy of prematurity in 70 preterm infants.
Key points
- Cyclopentolate hydrochloride is an anticholinergic eye drop used to dilate the pupil.
- It is already authorised as a medicine in the United States and the United Kingdom.
- One Phase 2 trial in retinopathy of prematurity includes cyclopentolate as part of standard care.
- The trial is authorised and plans to enrol 70 preterm infants.
- The trial measures pain during eye screening with the PIPP-R pain score.
- Cyclopentolate is given as eye drops in strengths of 0.5%, 1% and 2%.
What is cyclopentolate hydrochloride?
Cyclopentolate hydrochloride is an anticholinergic medicine prepared as a sterile, borate buffered solution for topical ocular use. It is supplied in three strengths: 0.5%, 1% and 2%. The medicine is already authorised as a prescription drug in the United States under an Abbreviated New Drug Application, and in the United Kingdom it is available as Minims Cyclopentolate Hydrochloride eye drops. The chemical name of cyclopentolate hydrochloride is 2-(Dimethylamino)ethyl 1-hydroxy-a-phenylcyclopentaneacetate hydrochloride.
How does cyclopentolate hydrochloride work?
Cyclopentolate hydrochloride blocks the responses of the sphincter muscle of the iris and the accommodative muscle of the ciliary body to cholinergic stimulation. This produces pupillary dilation, known as mydriasis, and paralysis of accommodation, known as cycloplegia. The medicine acts rapidly, but has a shorter duration than atropine. Maximal cycloplegia occurs within 25 to 75 minutes after instillation. Complete recovery of accommodation usually takes 6 to 24 hours, while complete recovery from mydriasis in some individuals may require several days. Heavily pigmented irides may require more doses than lightly pigmented irides.
Which conditions is it used or studied for?
- Eye examinations — cyclopentolate is used to enlarge the pupil so that a doctor or eye specialist can examine the eye more closely.
- Inflammation of the eye — the eye drops are also used to treat some types of inflammation of the eye.
- Retinopathy of prematurity — in one clinical trial, cyclopentolate eye drops are used as part of standard care during eye screening in preterm infants.
How is cyclopentolate hydrochloride given?
Cyclopentolate hydrochloride is given as eye drops, a solution for topical ocular use. In the clinical trial, the product used is Cyclopentolat Minims 10 mg/ml eye drops, solution, given at a dose of 150 micrograms by the ophthalmic route. The product information lists three strengths of cyclopentolate hydrochloride ophthalmic solution: 0.5%, 1% and 2%. The solution contains the preservative benzalkonium chloride 0.01%.
What do the clinical trials show?
One clinical trial in the EU Clinical Trials Information System involves cyclopentolate hydrochloride. The trial is called the PROPER study, with the full title “Pain Relief at Screening for Retinopathy of Prematurity”. It is a Phase 2 interventional study with a planned enrollment of 70 participants. The trial is currently authorised.
The trial investigates retinopathy of prematurity in preterm infants born at a gestational age of less than 30 weeks. The main question is whether intranasal dexmedetomidine at 2 micrograms per kilogram, given as an adjunct to standard care, provides lower procedural pain scores during retinopathy of prematurity screening compared to placebo. In this trial, cyclopentolate is not the substance being tested; it is part of the standard care given to all participants during the eye examination.
The primary outcome is the pain score assessed with the Premature Infant Pain Profile-Revised, known as PIPP-R, during the 30 seconds following speculum insertion at eye exam I and II. The interventions in the trial include oxibuprokain eye drops, dexmedetomidine nasal solution, metaoxedrin eye drops, sodium chloride nasal solution as placebo, and cyclopentolate eye drops.
What side effects are known?
The product information for Minims Cyclopentolate Hydrochloride eye drops describes side effects that patients should be aware of. Allergic reactions to the active substance or any of the other ingredients are possible. The medicine is not indicated for babies under 28 days old, unless a doctor or eye specialist decides that it is necessary. It should not be used in people with glaucoma or those at risk of having it, including people with a family history of glaucoma, those over 60, or those who have had eye surgery. It is also not to be used in children with brain damage, particularly if they may have seizures or fits. The product information advises caution in people whose eyes are red or inflamed, and in people with heart problems, in particular a fast heart rate.