Title: Cyclopentolate
CAS Registry Number: 512-15-2
CAS Name: a-(1-Hydroxycyclopentyl)benzeneacetic acid 2-(dimethylamino)ethyl ester
Additional Names: 1-hydroxy-a-phenylcyclopentaneacetic acid 2-(dimethylamino)ethyl ester; 2-dimethylaminoethyl 1-hydroxy-a-phenylcyclopentaneacetate; b-dimethylaminoethyl (1-hydroxycyclopentyl)phenylacetate; 2-phenyl-2-(1-hydroxycyclopentyl)ethanoic acid b-(dimethylamino)ethyl ester
Molecular Formula: C17H25NO3
Molecular Weight: 291.39
Percent Composition: C 70.07%, H 8.65%, N 4.81%, O 16.47%
Literature References: Ophthalmic anticholinergic. Prepn: Treves, US 2554511 (1951 to Schieffelin).
Derivative Type: Hydrochloride
CAS Registry Number: 5870-29-1
Trademarks: Ak-Pentolate (Akorn); Alnide (Cusi); Mydplegic (Cooper); Cyclogyl (Alcon); Mydrilate (Boehringer, Ing.); Zyklolat (Mann)
Molecular Formula: C17H25NO3.HCl
Molecular Weight: 327.85
Percent Composition: C 62.28%, H 7.99%, N 4.27%, O 14.64%, Cl 10.81%
Properties: Crystals from ethyl acetate, mp 137-141°. pH of 1% aq soln: 5.0-5.4. Freely sol in water, alcohol. Practically insol in ether.
Melting point: mp 137-141°
Therap-Cat: Mydriatic.
Keywords: Mydriatic; Antimuscarinic.
Cyclophosphamide Cyclopropane Cyclopropyl Methyl Ether Cyclorphan Cycloserine

Systematic (IUPAC) name
2-(dimethylamino)ethyl (1-hydroxycyclopentyl)(phenyl)acetate
Clinical data
Pregnancy cat. C
Legal status  ?
Routes Topic
CAS number 512-15-2 YesY
ATC code S01FA04
PubChem CID 2905
DrugBank DB00979
ChemSpider 2802 YesY
KEGG D07759 YesY
Chemical data
Formula C17H25NO3 
Mol. mass 291.385 g/mol
 N (what is this?)  (verify)

Cyclopentolate is a medication commonly used during pediatric eye examinations that dilates the eye (mydriatic), prevents accommodation of the eye to different distances (cycloplegic), and blocks specific receptors called muscarinic receptors (muscarinic antagonist).[1] Cyclopentolate is also administered as an atropine substitute to reverse muscarinic and central nervous system effects of indirect cholinomimetic (anti-AChase) administration.

When used in eye drops in pediatric eye examinations, cyclopentolate 0.5 percent and 1.0 percent is used to stop the eye focusing at near distance, enabling the ophthalmologist, optometrist, or orthoptist to obtain a more accurate reading of the focusing power of the eyes. Brand names include Cyclogyl, Cylate, & Pentolair.[2]

The drops take around 30-60 minutes to work and less than 24 hours to wear off (with patients advised not to drive a vehicle or operate machinery for the first 12 hours). The pupils become wider when cyclopentolate is administered, making the eyes more sensitive to light. Close objects (and possibly distant objects) will also appear blurred.

Side effects to cyclopentolate are rare, but can include effects such as disorientation, incoherent speech or visual disturbances during the 24-hour period that the drug has an effect. The side effects are more common in children.

Both eyes instilled with cyclopentolate 1%, causing both mydriasis and cycloplegia
Cycloplegia caused by cyclopentolate 1% instilled into both eyes