Tropicamide

S01F - Mydriatics and cycloplegics ATC S01FA06 Small molecule approved 1960 Topical Natural product

JFDA label: Mydriacyl 1% E/D

Mechanism of Action

Antagonist of Muscarinic acetylcholine receptor M3 — Muscarinic acetylcholine receptor M3 antagonist

Target	Action	Gene / class
Muscarinic acetylcholine receptor M3 efficacy	ANTAGONIST	CHRM3

Indications

Approved

Mydriasis/Cycloplegia

Contraindications

Source: Lexicomp

Hypersensitivity to tropicamide or any component of the formulation Documentation of allergenic cross-reactivity for belladonna alkaloids is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty Absolute

Adverse Reactions

Very Common >10%Common 1–10%Uncommon 0.1–1% Rare 0.01–0.1%Very Rare <0.01%Not Known

Cardiac disorders (2)

Not Known Central nervous system dysfunction · tachycardia

Nervous system disorders (1)

Not Known Headache

Immune system disorders (1)

Not Known Hypersensitivity reaction

Gastrointestinal disorders (3)

Not Known Nausea · vomiting · xerostomia

Skin and subcutaneous tissue disorders (1)

Not Known Pallor

Musculoskeletal and connective tissue disorders (1)

Not Known Muscle rigidity

Eye disorders (4)

Not Known Blurred vision · photophobia · stinging of eyes (transient) · superficial punctate keratitis

Dosing

Source: Lexicomp

Note: Individuals with heavily pigmented eyes may require higher strength or additional doses: Cycloplegia: Ophthalmic: Instill 1 to 2 drops (1%) in the eye(s); repeat in 5 minutes. If the patient is not examined within 20 to 30 minutes, instill an additional drop to prolong effect. Mydriasis: Ophthalmic: Instill 1 to 2 drops (0.5%) in the eye(s) 15 to 20 minutes before exam

(For additional information see "Tropicamide: Pediatric drug information") Cycloplegia, mydriasis: Children and Adolescents: Refer to adult dosing.

Refer to adult dosing.

There are no dosage adjustments provided in the manufacturer’s labeling.

Warnings & Precautions

Source: Lexicomp

CNS effects

May cause drowsiness and/or blurred vision, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery, driving).

Increased intraocular pressure

May cause a transient increase in intraocular pressure. Special populations:

Contact lens wearers

Contains benzalkonium chloride, which may be absorbed by soft contact lenses; remove lenses prior to administration.

Pediatric

Use with caution in infants and children; may cause potentially dangerous CNS disturbances. Psychotic reactions, behavioral disturbances, and vasomotor or cardiorespiratory collapse in children have been reported with the use of anticholinergic drugs. Other warnings/precautions:

Appropriate use

For topical ophthalmic use only. Remove contact lenses prior to administration. To avoid excessive systemic absorption, apply gentle finger pressure to lacrimal sac for 2 to 3 minutes following application. Do not touch dropper tip to eyelids or any surface.

Pregnancy & Lactation

Pregnancy

FDA category C

Animal reproduction studies have not been conducted. If ophthalmic agents are needed during pregnancy, the minimum effective dose should be used in combination with punctual occlusion to decrease potential exposure to the fetus (Samples, 1988).

Lactation

It is not known if tropicamide is excreted in breast milk. The manufacturer recommends that caution be used if administered to nursing women.

Monitoring

Clinical pearl	Ophthalmic exam, intraocular pressure, CNS reactions (especially in pediatric patients).

Chemistry & Properties

Formula	C17H20N2O2
Molecular weight	284.36 g/mol
IUPAC name	N-ethyl-3-hydroxy-2-phenyl-N-(pyridin-4-ylmethyl)propanamide
CAS	1508-75-4
PubChem CID	5593
InChIKey	`BGDKAVGWHJFAGW-UHFFFAOYSA-N`
logP	2.21 (XLogP 1.5)
Polar surface area	53.43 Å²
H-bond acceptors / donors	3 / 1
Drug-likeness (QED)	0.88
Lipinski violations	0

SMILES

CCN(Cc1ccncc1)C(=O)C(CO)c1ccccc1

Biology & Pharmacokinetics

Pharmacokinetics

BBB penetrant	No

Enzyme interactions

Enzyme	Role	Detail
CYP1A2	Inhibitor	—
CYP1A2	Substrate	—
CYP2B6	Inhibitor	—
CYP2C19	Inhibitor	IC₅₀ 1.0 µM
CYP2C8	Inhibitor	—
CYP2C9	Inhibitor	IC₅₀ 1.0 µM
CYP3A4	Inhibitor	—
CYP3A4	Substrate	—

Receptor binding (top 5)

Target	Action	Affinity
Cholinergic, muscarinic M4 (CHRM4)	Binding	pKi 8.5
M2 receptor (CHRM2)	Antagonist	pKi 7.2
M3 receptor (CHRM3)	Antagonist	pKi 7.0
M4 receptor (CHRM4)	Antagonist	pKi 6.9
M5 receptor (CHRM5)	Antagonist	pKi 6.4

Transporters

BCRP (Inhibitor)BSEP (Inhibitor)MRP1 (Inhibitor)OATP1B1 (Inhibitor)OATP1B1 (Inhibitor)OATP1B3 (Inhibitor)OATP1B3 (Inhibitor)OCT2 (Inhibitor)P-gp (Inhibitor)P-gp (Substrate)

Registered Products (3)

Brand	Form / strength	Pack	Agent	Citizen (JOD)
Minims Tropicamide B.P 0.5% e/d	Ophthalmic Solution 0.5 %	0.5 ml	Petra Drug Store	—
Minims Tropicamide B.P 1% e/d	Ophthalmic Solution 1 %	0.5 ml	Petra Drug Store	—
Mydriacyl 1% E/D	Ophthalmic Solution 1 %	15 ml	Modern Drug Store	—