Tropicamide

Overview

Tropicamide, sold under the brand name Mydriacyl among others, is a medication used to dilate the pupil and help with the examination of the eye. Specifically it is used to help examine the back of the eye. It is applied as eye drops. Effects occur within 40 minutes and last for up to a day.[1][2] WP

Common side effects include blurry vision, increased intraocular pressure, and sensitivity to light. Another rare but severe side effect is psychosis, particularly in children. It is unclear if use during pregnancy is safe for the fetus. Tropicamide is in the antimuscarinic part of the anticholinergic family of medications. It works by making the muscles within the eye unable to respond to nerve signals.[1][3] WP

Tropicamide was approved for medical use in the United States in 1960. It is on the World Health Organization's List of Essential Medicines.[1][4] WP

Uses, dosage and effects

Medical use

Tropicamide is an antimuscarinic drug that produces short acting mydriasis (dilation of the pupil) and cycloplegia when applied as eye drops. It is used to allow better examination of the lens, vitreous humor, and retina. Due to its relatively short duration of effect (4–8 hours), it is typically used during eye examinations such as the dilated fundus examination, but it may also be used before or after eye surgery. Cycloplegic drops are often also used to treat anterior uveitis, decreasing the risk of posterior synechiae and decreasing inflammation in the anterior chamber of the eye.[5] WP⚠ Wikipedia itself has flagged this text: citation needed.

Tropicamide is occasionally administered in combination with p-hydroxyamphetamine (brand name Paremyd), which is a sympathomimetic. The use of the sympathomimetic drug causes the iris dilator muscle to be directly stimulated, causing increased dilation. In the United States, the sympathomimetic drop most commonly used along with tropicamide, is 2.5% phenylephrine hydrochloride (brand name AK-Dilate). WP⚠ Wikipedia itself has flagged this text: citation needed.

Recreational use

Tropicamide is sometimes abused (injected intravenously e.g. by insulin syringe) as an inexpensive recreational deliriant drug (along with naphazoline). This was initially reported in Russia, but has subsequently spread to various other countries in the former Soviet Union and around Europe, and later in the United States.[6][7][8] WP

Tropicamide severely destroys internal organs when injected.[9] WP

Risks and side effects

Side effects

Tropicamide induces transient stinging and a slight and transient rise in intraocular pressure in the majority of patients. It may cause redness or conjunctivitis (inflammation) and also blurs near vision for a short while after instillation (care must be taken, and the patient must only drive when vision returns to normal). Tropicamide may, in very rare cases, cause an attack of acute angle-closure glaucoma. This tends to be in patients with narrow anterior chamber angles, and closure risk must be assessed by the practitioner prior to instillation.[10] WP⚠ Wikipedia itself has flagged this text: citation needed.

Tropicamide is often preferred to atropine because atropine has a longer half-life, causing prolonged dilation and blurry vision for up to a week. Atropine has less sting effect, but can be toxic or fatal if ingested in large quantities by children or adults. WP⚠ Wikipedia itself has flagged this text: citation needed.

With eye drops, systemic effects are minimal to nonexistent due to very low absorption into the bloodstream.[11] WP

Pharmacology

Pharmacodynamics

Tropicamide is an anticholinergic. It is specifically an antimuscarinic, acting as a selective muscarinic acetylcholine M₁ and M₄ receptor antagonist. However, it has also been reported to be a non-selective antagonist of all five muscarinic acetylcholine receptors. As with other antimuscarinics, tropicamide can produce deliriant effects.[12][13] WP

Chemistry

Formula

C17H20N2O2 PC

CAS number

1508-75-4 PC

Molar mass (g/mol)

284.35 PC

IUPAC name (computed by PubChem)

N-ethyl-3-hydroxy-2-phenyl-N-(pyridin-4-ylmethyl)propanamide PC

SMILES

CCN(CC1=CC=NC=C1)C(=O)C(CO)C2=CC=CC=C2 PC

InChIKey

BGDKAVGWHJFAGW-UHFFFAOYSA-N PC

PubChem CID

5593

IUPAC name

(RS)-N-Ethyl-3-hydroxy-2-phenyl-N-(pyridin-4-ylmethyl)propanamide WP

Harm reduction information

No harm reduction data is on file for this compound yet. That means no dose, timing or combination data from PsychonautWiki or TripSit. Please don't guess a dose from similar compounds. If you have taken it and feel unwell, contact emergency services or a poison control center.

User reports

Pop culture

No references added yet.

Sources

1. Other Tropicamide
2. Other WHO Model Formulary 2008. 2009
3. Other Tropicamide ophthalmic Use During Pregnancy
4. Other World Health Organization model list of essential medicines: 21st list 2019. 2019
5. Journal / agency Manny RE, Hussein M, Scheiman M, Kurtz D, Niemann K, Zinzer K. Tropicamide (1%): an effective cycloplegic agent for myopic children. Investigative Ophthalmology & Visual Science. July 2001. PMID 11431435
6. Journal / agency Bersani FS, Corazza O, Simonato P, Mylokosta A, Levari E, Lovaste R, Schifano F. Drops of madness? Recreational misuse of tropicamide collyrium; early warning alerts from Russia and Italy. General Hospital Psychiatry. 2013. doi:10.1016/j.genhosppsych.2013.04.013 · PMID 23706777
7. Journal / agency Bersani FS, Imperatori C, Prilutskaya M, Kuliev R, Corazza O. Injecting eye-drops: a mini-review on the non-clinical use of tropicamide. Hum Psychopharmacol. July 2015. doi:10.1002/hup.2481 · PMID 26216560
8. Journal / agency Bellman V, Ukolova A, Erovichenkova E, Lam S, Srivastava HK, Bruce J, Burgess DM. Abuse of tropicamide eye drops: review of clinical data. Braz J Psychiatry. November 2022. doi:10.47626/1516-4446-2021-2446 · PMID 35739063 · PMC9561840
9. Journal / agency Bellman, V., Ukolova, A., Erovichenkova, E., Lam, S., Srivastava, H. K., Bruce, J., & Burgess, D. M. (2022). Abuse of tropicamide eye drops: review of clinical data. Revista brasileira de psiquiatria (Sao Paulo, Brazil: 1999). Braz J Psychiatry. 2 Nov 2022
10. Journal / agency Liew G, Mitchell P, Wang JJ, Wong TY. Fundoscopy: to dilate or not to dilate?. BMJ. January 2006. doi:10.1136/bmj.332.7532.3 · PMID 16399709 · PMC1325111
11. Journal / agency Vuori ML, Kaila T, Iisalo E, Saari KM. Systemic absorption and anticholinergic activity of topically applied tropicamide. Journal of Ocular Pharmacology. 1994-01-01. doi:10.1089/jop.1994.10.431 · PMID 8083562
12. Journal / agency Lakstygal AM, Kolesnikova TO, Khatsko SL, Zabegalov KN, Volgin AD, Demin KA, Shevyrin VA, Wappler-Guzzetta EA, Kalueff AV. DARK Classics in Chemical Neuroscience: Atropine, Scopolamine, and Other Anticholinergic Deliriant Hallucinogens. ACS Chem Neurosci. May 2019. doi:10.1021/acschemneuro.8b00615 · PMID 30566832
13. Journal / agency Lavrador M, Cabral AC, Veríssimo MT, Fernandez-Llimos F, Figueiredo IV, Castel-Branco MM. A Universal Pharmacological-Based List of Drugs with Anticholinergic Activity. Pharmaceutics. January 2023. doi:10.3390/pharmaceutics15010230 · PMID 36678858 · PMC9863833

Text and values on this page are quoted from Wikipedia (CC BY-SA 4.0), PubChem (public domain). Each value links to the exact revision it came from.