antazoline

Action and Spectrum

Actions and spectrum: 

• Antihistaminic Action: antazoline is a first-generation antihistamine. It competes with histamine for binding to H1 receptors on cells throughout the body in the respiratory and vascular systems. 
• Histamine Blockade: By binding to H1 receptors, antazoline inhibits the effects of histamine. Histamine is involved in various allergic reactions and is responsible for symptoms such as itching, sneezing, runny nose, and watery eyes. 
• Symptom Relief: antazoline is commonly used to relieve symptoms associated with allergic conjunctivitis, including itching and redness of the eyes. 
• Vasoconstrictor Effects: antazoline may also possess vasoconstrictor effects, helping to reduce redness and swelling in the eyes. 
• Ophthalmic Use: antazoline is often formulated with other medications (such as naphazoline) in ophthalmic solutions to provide relief from allergic symptoms affecting the eyes. 
• Limited Systemic Effects: While antazoline acts locally in the eyes, its systemic absorption is limited when used topically. This minimizes the potential for widespread antihistaminic effects in the body.

Drug Interaction

Adverse Reaction

Frequency not defined 

Skin sensitization 

Hypersensitivity reactions 

Black Box Warning

Black Box Warning: 

antazoline does not have any black box warning. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• Hypersensitivity: antazoline is contraindicated in individuals who have a known hypersensitivity or allergy to antazoline or any of the other components in the formulation. 
• Narrow-Angle Glaucoma: antazoline may have anticholinergic effects and can potentially narrow the angle of the anterior chamber of the eye. It is generally contraindicated in individuals with narrow-angle glaucoma. 
• Eye Infections or Injury: antazoline is generally contraindicated in individuals with eye infections or injury, as it may exacerbate these conditions. 
• Children Under 6 Years of Age: The safety and efficacy of antazoline in children under the age of 6 may not be established, and its use may be contraindicated in this age group. 
• Breastfeeding: Although antazoline is primarily used topically in the eyes, there may be limited systemic absorption. As a precaution, it may be contraindicated or used with caution in breastfeeding women. 

Caution: 

• Systemic Absorption: While antazoline is primarily used topically in the eyes, there may be limited systemic absorption. Caution is advised, especially in individuals with certain medical conditions or those taking other medications, to minimize potential systemic effects. 
• Eye Irritation: antazoline-containing ophthalmic solutions may cause transient stinging or burning upon instillation. Individuals experiencing persistent irritation should seek advice from a healthcare professional. 
• Contact Lenses: Some ophthalmic formulations containing antazoline may contain preservatives that can be absorbed by the soft contact lenses. Patients are typically advised to remove contact lenses before using the medication and wait a specified amount of time before reinserting them. 
• Pre-Existing Eye Conditions: Caution is recommended in individuals with pre-existing eye conditions, such as dry eyes or certain types of glaucoma. antazoline may exacerbate certain eye conditions, and its use should be discussed with a healthcare provider. 
• Pediatric Use: Caution is recommended when using antazoline in pediatric populations. The safety and efficacy of some formulations may not be well-established in young children, and healthcare provider guidance is essential. 

Comorbidities: 

• Eye Conditions: Individuals with pre-existing eye conditions, such as dry eyes or certain types of glaucoma, may need to exercise caution when using antazoline. The medication may exacerbate certain eye conditions, and its use should be discussed with a healthcare provider. 
• Contact Lens Wear: antazoline-containing ophthalmic solutions may contain preservatives that can be absorbed by soft contact lenses. Contact lens wearers should follow specific instructions provided by their healthcare provider or on the medication label. 
• Allergies: Individuals with hypersensitivity or allergic reactions to antazoline or any of the components in the formulation should avoid its use. 
• Pediatric Population: The safety and efficacy of some formulations of antazoline in young children may not be well-established. Pediatric populations may require special consideration, and healthcare provider guidance is important. 

Pregnancy / Lactation

Pregnancy consideration: pregnancy category: not assigned 

Lactation: excreted into human milk: unknown   

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus 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: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

antazoline is a first-generation antihistamine with pharmacological properties that make it effective in managing allergic symptoms, particularly those affecting the eyes. As an antagonist of histamine at the H1 receptor, antazoline interferes with the actions of histamine, a key mediator of allergic responses. By blocking histamine, antazoline mitigates symptoms such as itching, and redness associated with allergic conjunctivitis.

When applied topically in ophthalmic formulations, antazoline’s effects are primarily localized to the eyes, minimizing systemic absorption. While it provides relief from ocular allergic symptoms, it is important for individuals to follow healthcare provider recommendations and be aware of any contraindications or cautions associated with specific formulations. 

Pharmacodynamics: 

• Histamine Receptor Antagonism: antazoline acts as an antagonist at H1 receptors, specifically those that bind histamine. By binding to these receptors, antazoline inhibits the actions of histamine. 
• Reduction of Allergic Symptoms: Histamine is responsible for various allergic symptoms, including itching, redness, and increased vascular permeability. By blocking H1 receptors, antazoline reduces these symptoms, particularly when applied topically in ophthalmic formulations. 
• Anti-Itch (Antipruritic) Effects: antazoline’s ability to block histamine receptors contributes to its antipruritic effects, helping to alleviate itching associated with allergic reactions. 
• Vasoconstrictor Effects: Some formulations of antazoline may possess vasoconstrictor effects, contributing to the reduction of redness and swelling in the eyes. 
• Local Action in the Eyes: When used in ophthalmic solutions, antazoline’s effects are primarily localized to the eyes, where it provides relief from allergic symptoms affecting the ocular tissues. 

Pharmacokinetics: 

• Absorption: antazoline is commonly administered topically in ophthalmic solutions for ocular use to alleviate allergic symptoms. When applied to the eyes, it is absorbed locally through the conjunctiva and cornea. Systemic absorption is limited, reducing the risk of widespread effects. 
• Distribution: Following absorption, antazoline is distributed within the ocular tissues. Due to its primarily localized action in the eyes, distribution to other tissues is limited. antazoline’s effects are targeted to the site of application, providing relief from allergic symptoms in the eyes. 
• Metabolism: Information on the hepatic metabolism of antazoline is limited. It is considered that the metabolism of antazoline is not a major factor in its pharmacokinetics.  
• Excretion: The excretion of antazoline occurs through multiple routes. Metabolites, if any, and the unchanged drug may be eliminated via renal excretion and, to a lesser extent, through feces. The specific elimination pathways and the extent of renal excretion may vary. 

Adminstartion

Administration: 

• Wash Hands: Before applying any ophthalmic solution, it is important to wash your hands thoroughly to prevent contamination. 
• Prepare the Eye: Tilt your head back or lie down and look upward. 
• Instill the Drops: Hold the container of antazoline eye drops over the eye, taking care not to touch the tip to any surface. Squeeze the prescribed number of drops into the pocket formed by the lower eyelid. Be cautious not to touch the eye with the dropper. 
• Close the Eye: Close your eye gently for a moment to allow the solution to spread across the surface of the eye. 
• Press on the Inner Corner: After instilling the drops, press on the inner corner of the eye (near the nose) with your finger for about one to two minutes. This helps to minimize systemic absorption and reduce the potential for side effects. 
• Avoid Blinking: Try to avoid blinking excessively immediately after instilling the drops to ensure proper distribution. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: antazoline 

Pronounced: (an-TAZ-oh-leen)  

Why do we use antazoline? 

antazoline is frequently used in ophthalmic solutions to alleviate symptoms of allergic conjunctivitis. These symptoms may include itching, redness, and discomfort in the eyes due to exposure to allergens such as pollen, pet dander, or dust. The antihistaminic properties of antazoline make it effective in reducing itching and redness in the eyes caused by histamine release during allergic reactions. antazoline is specifically formulated for ophthalmic use, providing targeted relief at the site of application without significant systemic effects.