tropicamide

Action and Spectrum

Actions and spectrum: 

tropicamide is an anticholinergic drug used as a mydriatic and cycloplegic agent. It works by blocking the action of acetylcholine, a neurotransmitter responsible for the contraction of the iris sphincter muscle and ciliary muscle in the eye. As a result, tropicamide causes the pupil to dilate and the ciliary muscle to relax, allowing for a better view of the back of the eye during an eye exam or surgery. 

tropicamide has a rapid onset of action, with maximal dilation occurring within 15-30 minutes after administration. Its effects typically last for 4-6 hours. tropicamide is primarily used in ophthalmology for diagnostic and therapeutic purposes, including dilation of the pupil for examination of the retina and optic nerve and for the treatment of certain eye conditions such as iritis and uveitis. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Increased IOP 

Dry mouth 

Photophobia 

Headache 

Allergic reactions 

Transient stinging 

Blurred vision 

Tachycardia 

Parasympathetic stimulation 

Black Box Warning

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

tropicamide is contraindicated in patients with narrow-angle glaucoma, shallow anterior chamber, and hypersensitivity to any component of the medication. It should also be used with caution in patients with angle-closure glaucoma, cardiovascular disease, hypertension, and hyperthyroidism.  

Caution: 

• Glaucoma: tropicamide can increase intraocular pressure, which can be dangerous for people with glaucoma. It should be used with caution in these patients. 
• Allergy: Patients with a known hypersensitivity to tropicamide or other anticholinergic medications should avoid using this medication. 
• Pregnancy and breastfeeding: tropicamide are classified as a pregnancy category C medication, which means that it may not be safe for use during pregnancy. It is also unknown whether tropicamide can pass into breast milk, so women who are breastfeeding should consult with their healthcare provider before using this medication. 
• Children and elderly: tropicamide should be used with caution in children and elderly patients, as they may be more sensitive to the medication’s effects. 
• Medical conditions: tropicamide should be used with caution in patients with certain medical conditions, such as heart disease, hyperthyroidism, or gastrointestinal obstruction. It may worsen these conditions or interact with other medications.

Comorbidities: 

• Glaucoma: tropicamide can increase intraocular pressure, so patients with narrow-angle glaucoma or a history of elevated intraocular pressure should be monitored closely. 
• Cardiovascular disease: tropicamide can cause tachycardia and arrhythmias, so patients with cardiovascular diseases, such as angina, myocardial infarction, heart failure, and hypertension, should be monitored closely. 
• Hepatic impairment: tropicamide is metabolized in the liver, so patients with hepatic impairment may have a reduced ability to metabolize and eliminate the drug. 
• Renal impairment: tropicamide is excreted by the kidneys, so patients with renal impairment may have a reduced ability to excrete the drug. 
• Thyroid dysfunction: tropicamide can interfere with thyroid function tests, so patients with thyroid dysfunction should inform their healthcare provider before taking the medication. 
• Allergies: Patients with a history of allergies to tropicamide or any other components of the medication should avoid its use. 

Pregnancy / Lactation

Pregnancy consideration: Pregnancy Category: C 

Lactation: safety and efficacy not established  

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

tropicamide is an anticholinergic agent that acts by blocking the muscarinic receptors in the eye, specifically the M3 receptors, resulting in dilation of the pupil (mydriasis) and paralysis of the ciliary muscle (cycloplegia). It is a quaternary ammonium compound that cannot cross the blood-brain barrier, limiting its systemic effects.  

Pharmacodynamics: 

tropicamide is a competitive antagonist of acetylcholine muscarinic receptors in the parasympathetic nervous system. It produces its pharmacodynamic effect by selectively blocking the muscarinic receptors in the iris sphincter muscle and the ciliary muscle of the eye.

tropicamide causes a rapid and transient dilation of the pupil (mydriasis) and cycloplegia, resulting in a temporary loss of accommodation (cycloplegia), which is used to facilitate ophthalmologic examination and procedures. The onset of action of tropicamide is within 15-30 minutes after administration, and its effect can last for up to several hours, depending on the dose and individual response.  

Pharmacokinetics: 

Absorption 

tropicamide is rapidly absorbed following ocular administration. Its onset of action is usually within 20 to 40 minutes, and the maximum effect occurs within 1 hour. 

Distribution 

tropicamide is distributed throughout the body and can cross the blood-brain barrier. It is also excreted into breast milk. 

Metabolism 

tropicamide is metabolized primarily in the liver by ester hydrolysis, yielding inactive metabolites. 

Elimination and excretion 

tropicamide and its metabolites are excreted primarily in the urine, with a small amount excreted in feces. The elimination half-life is approximately 2 to 4 hours. 

Adminstartion

Administration: 

tropicamide is commonly administered as an ophthalmic solution for topical use in the eye. The usual dose is 1 or 2 drops of a 0.5% or 1% solution into the affected eye(s) up to three times daily. The exact dosing regimen may vary depending on the patient’s age, condition, and response to treatment.

It is important to avoid touching the tip of the dropper to the eye or other surfaces to prevent contamination. Contact lenses should be removed before using tropicamide and may be reinserted 15 minutes after use. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: tropicamide 

Pronounced: ( troe-PIK-a-mide )  

Why do we use tropicamide? 

tropicamide is mainly used as a mydriatic and cycloplegic agent in ophthalmic examinations. It is used to dilate the pupil of the eye for various diagnostic and therapeutic purposes such as eye examinations, retinal examination and to treat some eye conditions such as uveitis and iritis.

tropicamide is also used in combination with phenylephrine to produce mydriasis before ophthalmic surgery. Additionally, it can be used in the treatment of amblyopia (lazy eye) and strabismus (crossed eyes) in children, as it helps to prevent one eye from dominating the visual process.