emedastine

Action and Spectrum

Actions and Spectrum: 

emedastine is an antihistamine drug. It is used to treat symptoms of allergic conjunctivitis (itchy, watery eyes) and other allergic conditions of the eye

Drug Interaction

Adverse Reaction

>10%: 

Headache (11%) 

Frequency undefined: 

Dry eye 

Keratitis 

Tearing 

Asthenia 

Rhinitis 

Sinusitis 

Abnormal dreams 

Bad taste 

Corneal staining 

Blurred vision 

Ocular hyperemia 

Black Box Warning

Black Box Warning: 

It is essential to follow the dosage and administration instructions for emedastine carefully. Do not touch the vial after opening it

Contraindication / Caution

Contraindication/Caution: 

emedastine should not be used in people hypersensitive to the drug itself

Pregnancy / Lactation

Pregnancy consideration:  

Category B 

Breastfeeding warnings:  

No data is available regarding the presence of drugs in human breast milk. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies do not show risk to the fetus in the first/later trimester.        
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.        
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.       
• Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.        
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.        
• Category N: No data is available for the drug under this category

Pharmacology

Pharmacology 

emedastine is a second-generation antihistamine that blocks histamine’s action on H1 receptors. Histamine is a chemical released by the body in response to an allergic trigger, such as pollen or pet dander. When histamine binds to H1 receptors on blood vessels and smooth muscle. 

Pharmacodynamics: 

emedastine is available as eye drops, and the conjunctiva quickly absorbs it. It has a high affinity for H1 receptors and a long duration of action. It is due to the slow dissociation of the drug from the receptors. Once absorbed, it is metabolized by the liver into an inactive metabolite and excreted by the kidneys. 

Pharmacokinetics: 

emedastine shows a low systemic exposure. The half-life of the drug is 3-4 hours. 

Absorption 

Emedastine is rapidly absorbed after topical-ocular administration and reaches peak plasma concentrations within 15-30 minutes 

Distribution 

The exact distribution of emedastine is not well understood, but it is thought to bind to H1 receptors in the eyes and the peripheral tissues. It does not cross the blood-brain barrier significantly, which helps minimize the risk of side effects on the central nervous system. 

Metabolism 

emedastine is metabolized in the liver by several enzymes, including cytochrome P450 3A4 (CYP3A4), into an inactive metabolite. The metabolite is excreted in the urine. 

Elimination and excretion 

The elimination half-life of emedastine is approximately 2-3 hours, meaning it takes about 2-3 hours for half of the drug to be eliminated from the body. The half-life is short, allowing the drug to be eliminated from the body in a relatively short amount

Adminstartion

Administration: 

The emedastine is administered through the ocular route

Patient Information Leaflet

Patient information leaflet 

Generic Name: emedastine  

Pronounced: em-e-DAS-teen 

Why do we use emedastine? 

emedastiine helps to treat allergic conjunctivitis