Editing Cyclopentolate

{{Short description|Pair of enantiomers}}
{{Drugbox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 460110763
| IUPAC_name = (''RS'')-2-(dimethylamino)ethyl (1-hydroxycyclopentyl)(phenyl)acetate
| image = Cyclopentolate.png
| image_class = skin-invert-image
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 2802
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = I76F4SHP7J
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C17H25NO3/c1-18(2)12-13-21-16(19)15(14-8-4-3-5-9-14)17(20)10-6-7-11-17/h3-5,8-9,15,20H,6-7,10-13H2,1-2H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = SKYSRIRYMSLOIN-UHFFFAOYSA-N
| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 512-15-2
| ATC_prefix = S01
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1200473
| ATC_suffix = FA04
| ATC_supplemental = 
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00979
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 4024
| PubChem = 2905
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D07759
| smiles = O=C(OCCN(C)C)C(c1ccccc1)C2(O)CCCC2
| C=17 | H=25 | N=1 | O=3
| bioavailability = 
| protein_bound = 
| metabolism = 
| elimination_half-life = 
| pregnancy_category = C
<!-- Legal status -->
| legal_AU = <!-- Unscheduled / S2 / S3 / S4 / S5 / S6 / S7 / S8 / S9 -->
| legal_BR = C1
| legal_BR_comment = <ref>{{Cite web |author=Anvisa |author-link=Brazilian Health Regulatory Agency |date=2023-03-31 |title=RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial |trans-title=Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control|url=https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |url-status=live |archive-url=https://web.archive.org/web/20230803143925/https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |archive-date=2023-08-03 |access-date=2023-08-16 |publisher=[[Diário Oficial da União]] |language=pt-BR |publication-date=2023-04-04}}</ref>
| legal_CA = <!--             / Schedule I, II, III, IV, V, VI, VII, VIII -->
| legal_DE = <!-- Anlage I, II, III or Unscheduled -->
| legal_NZ = <!-- Class A, B, C -->
| legal_UK = <!-- GSL         / P       / POM / CD / Class A, B, C -->
| legal_US = <!-- OTC                   / Rx-only  / Schedule I, II, III, IV, V -->
| legal_EU = 
| legal_UN = <!-- N I, II, III, IV / P I, II, III, IV -->
| legal_status = 
| routes_of_administration = Topic
}}

'''Cyclopentolate''' is a [[muscarinic antagonist]].<ref>{{cite web|url=http://www.drugbank.ca/drugs/DB00979|title=Cyclopentolate | work = Drug Bank |access-date=June 15, 2012}}</ref> It is commonly used as an eye drop during [[pediatric]] [[eye examination]]s to dilate the eye ([[mydriatic]]) and prevent the eye from focusing/[[Accommodation (eye)|accommodating]] ([[cycloplegia|cycloplegic]]).  Cyclopentolate{{cn|date=January 2024}} or [[atropine]] can also be administered to reverse muscarinic and central nervous system effects of indirect [[cholinomimetic]] (anti-AChase) administration.

It is on the [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO22nd">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 22nd list (2021) | year = 2021 | hdl = 10665/345533 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MHP/HPS/EML/2021.02 | hdl-access=free }}</ref>

After instillation of cyclopentolate, pupil dilation ([[mydriasis]]) typically lasts up to 24 hours, while paralysis of the [[ciliary muscle]] ([[cycloplegia]]) typically lasts 6-24 hours.<ref>{{cite book | chapter = Chapter 9: Cycloplegics. Table 9-1: Mydriatic and Cycloplegic Properties of Anticholinergic Agents | pages = 127 | veditors = Bartlett JD, Jaanus SD |title=Clinical Ocular Pharmacology |date=2008 |publisher=Butterworth Heinemann - Elsevier |location=Saint Louis |isbn=978-0-7506-7576-5 |edition=5th}}</ref> During this time, patients may be more light sensitive than normal and may notice close objects blurred (and possibly distant objects blurred, depending on the patient's visual system).  Cyclopentolate is often chosen as a milder, shorter-lasting, cycloplegic alternative to [[atropine]], another cycloplegic agent which lasts much longer.  [[Tropicamide]] is an even shorter-lasting cycloplegic than cyclopentolate, but is less reliable for finding latent hyperopia.  Cyclopentolate drops act rapidly to dilate the pupil.<ref>{{Cite web|url=http://www.medsafe.govt.nz/profs/Datasheet/c/Cyclogyleyedrop.pdf|title=Cyclogyl Eye Drops Medsafe data sheet New Zealand|date=11 January 2017|access-date=3 June 2017}}</ref>  

The side and adverse effects of cyclopentolate are similar to the side and adverse effects of other [[anticholinergic]] medications. Because of that, extra caution should be taken when prescribing cyclopentolate to patients who are already taking other anticholinergic drugs. A possible ocular ([[eye]]-related) side effect is increase in pressure inside the eye, which is of particular concern when there is a predisposition toward or a presence of [[glaucoma]]. Other ocular side effects can include burning sensations, discomfort with bright light ([[photophobia]]), blurred vision, irritation, inflammation of the eye mucous membranes ([[conjunctivitis]]), inflammation of the cornea of the eye ([[keratitis]]), and other issues. Nonocular (not eye-related) side and adverse effects can include neuropsychiatric symptoms.<ref name="pmid22217890">{{cite journal | vauthors = Derinoz O, Er A | title = Inability to walk, disequilibrium, incoherent speech, disorientation following the instillation of 1% cyclopentolate eyedrops: case report | journal = Pediatric Emergency Care | volume = 28 | issue = 1 | pages = 59–60 | date = January 2012 | pmid = 22217890 | doi = 10.1097/PEC.0b013e3182417a63 }}</ref> like subtle [[concentration]] and [[memory]] problems, subtle [[decision-making]] problems, [[drowsiness]], and more pronounced [[disorientation]] to time and place, [[confusion]], disturbances of [[speech]] and movement, [[hyperactivity]], [[Psychomotor agitation|restlessness]], and [[seizures]]. Temporary [[psychosis]]<ref>{{cite journal | vauthors = Rajappa N, Patra S, Bhalsing S, Lune AA | title = A case of acute psychosis induced by topical cyclopentolate eye drops in an elderly patient. | journal = Medical Journal of Dr. D.Y. Patil University | date = January 2014 | volume = 7 | issue = 1 | pages = 68–69 | doi = 10.4103/0975-2870.122789 | doi-access = free }}</ref> can develop that includes [[hallucinations]], particularly when higher doses are used in children or older adults<ref name="pmid2260344">{{cite journal | vauthors = Barker DB, Solomon DA | title = The potential for mental status changes associated with systemic absorption of anticholinergic ophthalmic medications: concerns in the elderly | journal =   DICP: The Annals of Pharmacotherapy| volume = 24 | issue = 9 | pages = 847–850 | date = September 1990 | pmid = 2260344 | doi = 10.1177/106002809002400911 | s2cid = 6896684 }}</ref> on other anticholinergic medications.<ref name="pmid6046837">{{cite journal | vauthors = Carpenter WT | title = Precipitous mental deterioration following cycloplegia with 0.2 percent cyclopentolate HCl | journal = Archives of Ophthalmology | volume = 78 | issue = 4 | pages = 445–447 | date = October 1967 | pmid = 6046837 | doi = 10.1001/archopht.1967.00980030447006 }}</ref> Patients with [[dementia]] of the Alzheimer's type can experience worsening of their dementia symptoms. Additional side and adverse effects can include skin flushing, skin rashes, gastrointestinal problems, increased heart beat ([[tachycardia]]), increased body temperature ([[hyperpyrexia]]), blood vessel dilation, [[urinary retention]], [[dry mouth]] and reduced [[sweating]], and reduced [[bronchial secretions]]. Severe poisoning with cyclopentolate may result in [[coma]], [[paralysis]] of breathing, and [[death]]. Cyclopentolate derivatives can be used as an antidote for [[organophosphate]] poisoning.<ref name="pmid19454862">{{cite journal | vauthors = Bryant SM, Rhee JW, Thompson TM, Lu JJ, Aks SE | title = Parenteral ophthalmic tropicamide or cyclopentolate protects rats from lethal organophosphate poisoning | journal = American Journal of Therapeutics | volume = 16 | issue = 3 | pages = 231–234 | date = 2009 | pmid = 19454862 | doi = 10.1097/MJT.0b013e318182254b | s2cid = 36599696 }}</ref><ref name="pmid4698940">{{cite journal | vauthors = Bauer CR, Trottier MC, Stern L | title = Systemic cyclopentolate (Cyclogyl) toxicity in the newborn infant | journal = The Journal of Pediatrics | volume = 82 | issue = 3 | pages = 501–505 | date = March 1973 | pmid = 4698940 | doi = 10.1016/s0022-3476(73)80134-9 }}</ref>
<ref name="pmid2113819">{{cite journal | vauthors = Fitzgerald DA, Hanson RM, West C, Martin F, Brown J, Kilham HA | title = Seizures associated with 1% cyclopentolate eyedrops | journal = Journal of Paediatrics and Child Health | volume = 26 | issue = 2 | pages = 106–107 | date = April 1990 | pmid = 2113819 | doi = 10.1111/j.1440-1754.1990.tb02399.x | s2cid = 20030473 }}</ref><ref name="pmid10750080">{{cite journal | vauthors = Bhatia SS, Vidyashankar C, Sharma RK, Dubey AK | title = Systemic toxicity with cyclopentolate eye drops | journal = Indian Pediatrics | volume = 37 | issue = 3 | pages = 329–331 | date = March 2000 | pmid = 10750080 | doi =  }}</ref><ref name="pmid24906272">{{cite journal | vauthors = Ozgun U, Demet T, Ozge KA, Zafer D, Murat S, Mehmet Y, Nilgun K | title = Fatal necrotising enterocolitis due to mydriatic eye drops | journal = Journal of the College of Physicians and Surgeons--Pakistan | volume = 24 | issue = Suppl 2 | pages = S147–S149 | date = May 2014 | pmid = 24906272 | doi =  }}</ref>

Lethality of cyclopentolate has been studied in rodents. The LD50 (the dose at which 50% of animals die from the drug) is approximately 4000 mg/kg in rats and 960 mg/kg in mice. Readily recognizable symptoms of overdose include [[tachycardia]], [[dizziness]], [[dry mouth]], [[behavioral disturbances]], [[uncoordination]], and [[drowsiness]].

[[Cycloplegia]] is necessary in cases of suspected latent [[hyperopia]] (or "over-focusing") so that an [[ophthalmologist]] or [[optometrist]] can accurately measure how much a person has to flex their [[Ciliary_muscle|focusing muscle]] ([[Accommodation (eye)|accommodation]]) in order to see in the distance and up-close.  Correction of latent hyperopia in children can often prevent, or sometimes correct, unwanted eye turns ([[strabismus]]), some forms of refractive [[amblyopia]], and may alleviate eye strain or frontal headaches caused by prolonged near-work.  Cycloplegia is also helpful in relieving [[Spasm_of_accommodation|accommodative spasm]].

== History ==
Cyclopentolate was first synthesized in 1952 as a chemical analogue of [[atropine]].  It was one of several derivatives of an analogue to tropic acid which were tested for pharmacological action "in a search for new and better [[antispasmodic]] agents."<ref name="TrevesTesta1952">{{cite journal|vauthors = Treves GR, Testa FC|title=Basic Esters and Quaternary Derivatives of β-Hydroxy Acids as Antispasmodics1|journal=Journal of the American Chemical Society|volume=74|issue=1|year=1952|pages=46–48|issn=0002-7863|doi=10.1021/ja01121a012}}</ref>

Brand names for cyclopentolate include Cyclogyl, Cylate, Mydrilate, and Pentolair.<ref>{{cite web|url=http://www.medicinenet.com/cyclopentolate_hydrochloride-eye_drops/article.htm|title=cyclopentolate hydrochloride solution - ophthalmic, Cyclogyl, Cylate, Pentolair|access-date=June 15, 2012}}</ref>  

[[Image:Cyclopentolate 1 percent Pupils.jpg|thumb|left|alt=Both eyes instilled with cyclopentolate 1%, causing both [[mydriasis]] and [[cycloplegia]]|Pupil dilation ([[mydriasis]]) caused by cyclopentolate 1% instilled into both eyes]] {{clear left}}

== References ==
{{Reflist}}

== Further reading ==
{{refbegin}}
* {{cite book| vauthors = Whitcher JP, Riordan-Eva P |title=Vaughan & Asbury's general ophthalmology|publisher=McGraw-Hill Medical|isbn=978-0071443142|page=63|edition=17th|date=2007-10-18 }}
{{refend}}

{{Mydriatics and cycloplegics}}
{{Muscarinic acetylcholine receptor modulators}}

[[Category:Acetate esters]]
[[Category:Cyclopentanes]]
[[Category:Dimethylamino compounds]]
[[Category:M1 receptor antagonists]]
[[Category:M2 receptor antagonists]]
[[Category:M3 receptor antagonists]]
[[Category:M4 receptor antagonists]]
[[Category:Ophthalmology drugs]]
[[Category:Tertiary alcohols]]