naphazoline/glycerin ophthalmic

Action and Spectrum

Actions and Spectrum: 

naphazoline acts as an alpha-adrenergic agonist, causing constriction of blood flow to the eyes and alleviating swelling associated with eye irritation or allergies. 

By constricting the blood vessels, naphazoline reduces blood flow to the eyes, alleviating redness and puffiness. 

It is important to note that naphazoline provides temporary relief and is not a treatment for the underlying cause of the eye condition. naphazoline ophthalmic preparations are formulated explicitly for eye-related conditions and symptoms.  

glycerin acts as a lubricating agent and ocular demulcent, soothing and relieving eye dryness and discomfort. 

glycerin helps retain moisture on the eye’s surface, preventing excessive evaporation and maintaining optimal hydration levels. 

It forms a protective layer over the eye’s surface, shielding it from external irritants and environmental factors. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Mild transient stinging  

Increased/decreased intraocular pressure 

Mydriasis 

Headache 

Blurred vision 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution 

Contraindications include: 

• Hypersensitivity 
• Close-angle glaucoma 
• Cardiovascular symptoms 
• Diabetes 
• Thyroid disorders 
• Prolonged usage 
• Pregnancy 
• Lactation 

Caution should be maintained in: 

• Contact lens holders 
• Other eye conditions 
• Systemic effects 

Pregnancy / Lactation

Pregnancy consideration:  

Category C. 

Breastfeeding warnings:  

Not known if the drug is secreted in breast milk. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies do not show fetal risks in the first or 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 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 for the drug under this category is available. 

Pharmacology

Pharmacology: 

naphazoline stimulates alpha-adrenergic receptors on the smooth muscle cells of blood vessels in the eyes. It further constricts the blood vessels, reducing blood flow and decreasing redness and swelling. 

Similar to its effects in the eyes, it causes vasoconstriction in the nasal blood vessels, relieving congestion and reducing nasal swelling. naphazoline is classified as a sympathomimetic drug because it copies the effects of the sympathetic nervous system. Activating alpha-adrenergic receptors increases the release of norepinephrine, a neurotransmitter that regulates blood vessel tone. 

glycerin acts as a lubricating agent and ocular demulcent. It provides a soothing effect and helps alleviate dryness and eye discomfort. glycerin helps retain moisture on the eye’s surface, preventing excessive evaporation and maintaining optimal hydration levels. glycerin forms a thin protective film over the eye’s surface, helping shield it from external irritants and environmental factors. 

Pharmacodynamics: 

Lubrication and ocular demulcent action: glycerin acts as a lubricant and ocular demulcent, providing a soothing effect to the eye’s surface. It helps alleviate dryness, discomfort, and irritation by coating the eye’s surface and reducing friction. Pharmacokinetics: 

Absorption 

The drug is absorbed minimally absorbed systemically. 

Distribution 

After absorption, naphazoline distributes locally in the eye tissues, primarily targeting the blood vessels within the conjunctiva and surrounding areas. Systemic distribution is minimal due to limited systemic absorption. 

Metabolism 

naphazoline undergoes hepatic metabolism, primarily through enzymatic oxidation. The specific metabolic pathways and metabolites produced need to be well-documented for naphazoline. However, it is generally considered to undergo extensive first-pass metabolism in the liver. 

Elimination and Excretion 

Metabolized naphazoline and its metabolites are excreted primarily through the kidneys. The exact elimination half-life of naphazoline ophthalmic is not readily available. Still, it is generally expected to be relatively short due to the rapid onset and short drug action duration. 

glycerine 

Absorption 

glycerin applied topically to the eye is not significantly absorbed into the systemic circulation. It mainly acts locally on the surface of the eye. 

Distribution  

glycerin remains predominantly localized within the eye and does not have significant distribution to other tissues or organs. 

Metabolism 

glycerin is metabolized by various enzymatic pathways, including conversion to glucose in the liver (glyconeogenesis). 

Elimination and Excretion 

Any minimal systemic absorption of glycerin is eliminated primarily through the urine. 

Adminstartion

Administration: 

Wash your hands thoroughly. Before handling the eye drops, ensure cleanliness and reduce the risk of contamination. Tilt your head back or lie down. To administer the eye drops, tilt your head slightly or lie on a flat surface, looking upward. Pull down the lower eyelid with one hand to create a small pocket. Hold the eye drop bottle or container above the eye and squeeze the product into the pocket formed by the lower eyelid. Do not touch your eye or any other surface to prevent contamination. 

Close your eyes gently after instilling the eye drops. This helps distribute the medication evenly over the surface of the eye. After closing your eyes, apply gentle pressure with a clean finger to the corner of your eye near the nose. This helps prevent the eye drops from draining into the tear duct and being absorbed systemically.

If your healthcare professional prescribes multiple eye drops, wait for the specified amount (usually a few minutes) before repeating the process for additional drops. Most eye drops should be stored at room temperature, away from direct sunlight or excessive heat. 

Patient Information Leaflet

Patient information leaflet 

Generic Name:  naphazoline/glycerin ophthalmic 

Pronounced: na-FAZ-oh-leen GLIS-er-in awf-thal-muhk 

Why do we use naphazoline/glycerin ophthalmic? 

It relieves congestion, eye allergies, conjunctivitis, and ocular irritation. 

It is important to note that naphazoline and glycerin ophthalmic temporarily relieve symptoms and do not treat the condition’s underlying cause.