naphazoline 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 eye 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.  

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 

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

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. This 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. Activating alpha-adrenergic receptors increases the release of norepinephrine, a neurotransmitter that regulates blood vessel tone. 

Pharmacodynamics: 

naphazoline has minimal systemic absorption when used as directed in ophthalmic or nasal preparations. Its effects are primarily localized to the administration site, reducing the risk of widespread side effects or interactions with other medications. The duration of naphazoline’s effects can vary, but it is generally short-lived. Repeated doses may be required for sustained relief of symptoms. 

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. 

Adminstartion

Administration: 

Wash your hands thoroughly. Tilt your head back or lie down: To administer the eye drops, tilt your head slightly or lie down 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 it gently into the lower eyelid.  

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 ophthalmic 

Pronounced: na-FAZ-oh-leen awf-thal-muhk 

Why do we use naphazoline ophthalmic? 

It relieves congestion, eye allergies, conjunctivitis, and ocular irritation. It is important to note that naphazoline ophthalmic temporarily relieves symptoms and does not treat the condition’s underlying cause. If you have persistent or worsening eye redness, itching, or any other concerning symptoms, it is advisable to consult a healthcare professional.