Tropicamide

Tropicamide

Systematic (IUPAC) name
N-ethyl-3-hydroxy-2-phenyl-N- (pyridin-4-ylmethyl) propanamide
Clinical data
Trade names	Mydriacyl
AHFS/Drugs.com	monograph
Pregnancy cat.	C
Legal status	?
Routes	topical eye drops
Pharmacokinetic data
Protein binding	45%
Identifiers
CAS number	1508-75-4 Y
ATC code	S01FA06
PubChem	CID 5593
DrugBank	APRD00287
ChemSpider	5391 N
UNII	N0A3Z5XTC6 N
KEGG	D00397 Y
ChEMBL	CHEMBL1200604 N
Chemical data
Formula	C17H20N2O2
Mol. mass	284.353 g/mol
N(what is this?)  (verify)

Tropicamide (Mydriacyl) is an anticholinergic used as a mydriatic. In Russia, it is used to some degree as an inexpensive recreational drug. When injected intravenously "the drug has severe psychiatric effects and brings on suicidal feelings." ^[1]

Uses

Tropicamide is an antimuscarinic drug that produces short acting mydriasis (dilation of the pupil) and cycloplegia^[2] 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 risk of posterior synechiae and decreasing inflammation in the anterior chamber of the eye.

Anisocoria caused by Tropicamide instilled into the right eye only.

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).

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 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 [1], 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.

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.

Systemic side effects are very rare.

References

1. ^ Krokodil: The drug that eats junkies
2. ^ Manny RE, Hussein M, Scheiman M, Kurtz D, Niemann K, Zinzer K (July 2001). "Tropicamide (1%): an effective cycloplegic agent for myopic children". Investigative ophthalmology & visual science 42 (8): 1728–35. PMID 11431435. http://www.iovs.org/cgi/pmidlookup?view=long&pmid=11431435.