azelastine ophthalmic

Action and Spectrum

Actions and Spectrum: 

azelastine ophthalmic is an antihistamine medication commonly used to treat allergic conjunctivitis (eye allergies). It is available as eye drops and works by blocking the effects of histamine, which causes allergic symptoms in the body. 

The action of azelastine ophthalmic involves inhibiting the release of histamine from mast cells and blocking histamine receptors in the eyes. Doing so helps reduce symptoms such as itching, redness, watering, and swelling of the eyes caused by allergic reactions. 

Regarding its spectrum, azelastine ophthalmic primarily targets the eyes and is used to treat ocular (eye) allergies. It is not intended for systemic use or for treating nasal allergies or other allergic conditions outside the eye. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Transient burning or stinging (30%) 

Bitter taste (10%) 

Headache (15%) 

Frequency not defined 

Rhinitis 

Pruritus 

Bitter taste 

Eye pain 

Fatigue 

Asthma 

Conjunctivitis 

Pharyngitis 

Temporary blurring 

Influenza-like symptoms 

Dyspnea 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

azelastine ophthalmic should be used with caution and under the supervision of a healthcare professional.  

• Hypersensitivity: azelastine ophthalmic should not be used in individuals with known hypersensitivity or allergy to azelastine or any other ingredients in the formulation. 
• Contact Lens Use: azelastine ophthalmic contains benzalkonium chloride, which soft contact lenses may absorb. Therefore, removing contact lenses before instilling eye drops is generally recommended. Lenses can be reinserted after 10 to 15 minutes following administration. 
• Eye Infections: azelastine ophthalmic is not indicated in eye infections caused by viruses, bacteria, or fungi. It should not be used for an active eye infection without appropriate anti-infective treatment. 
• Children: Safety and efficacy of azelastine ophthalmic in children below the age of three years have not been established.  
• Pregnancy and Breastfeeding: The safety of azelastine ophthalmic during pregnancy and breastfeeding has not been established.  
• Systemic Effects: Although azelastine ophthalmic is primarily used topically in the eye, it can be absorbed systemically. Individuals susceptible to antihistamines or pre-existing medical conditions may be at an enhanced risk of systemic effects. Caution should be exercised in these cases. 

Caution 

• Eye Irritation: azelastine ophthalmic may cause temporary eye irritation, such as burning, stinging, or discomfort upon instillation. If you experience persistent or severe eye irritation, discontinue use and consult your healthcare professional. 
• Vision Changes: azelastine ophthalmic may cause blurred vision or other vision changes in rare cases. See medical attention if you experience any visual disturbances while using this medication. 
• Allergic Reactions: Although rare, allergic reactions to azelastine ophthalmic can occur. If you experience signs of an allergic reactions, like hives, rash, itching, swelling (especially of the face, lips, or tongue), or difficulty breathing, seek immediate medical attention. 
• Use in Specific Populations: The safety and efficacy of azelastine ophthalmic in specific populations, such as elderly individuals or those with severe liver or kidney impairment, have not been well-established.  
• Drug Interactions: azelastine ophthalmic is generally not expected to interact significantly with other medications. However, it is always important to inform your healthcare professional about all your medications (including over-the-counter drugs and supplements) to avoid potential interactions. 
• Use in Children: The safety and efficacy of azelastine ophthalmic in children below the age of three years have not been established. Use in pediatric patients should be done under the supervision of a healthcare professional. 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA pregnancy category: C 

Lactation:   

Excreted into human milk: Not known. 

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: 

azelastine ophthalmic is an antihistamine medication with pharmacological effects by blocking the H1 histamine receptors in the eyes. It generally inhibits the release of histamine from mast cells, thereby reducing the allergic response in the ocular tissues.

By blocking histamine receptors, azelastine ophthalmic prevents the binding of histamine, which produces symptoms such as itching, redness, watering, and swelling associated with allergic conjunctivitis.

The exact mechanism of action of azelastine ophthalmic is not fully understood, but its antihistaminic properties contribute to its ability to alleviate allergic symptoms in the eyes. 

Pharmacodynamics: 

Mechanism of action: The action of azelastine ophthalmic involves its antihistaminic properties and its ability to block H1 histamine receptors in the eyes. It acts as a selective antagonist at these receptors, preventing the binding of histamine to the receptor sites. By blocking the H1 histamine receptors in the ocular tissues, azelastine inhibits the effects of histamine, which is released during an allergic reaction. 

Histamine is a chemical mediator released from mast cells in response to an allergen exposure. It contributes to developing allergic symptoms in the eyes, such as itching, redness, watering, and swelling. By blocking the H1 histamine receptors, azelastine ophthalmic helps to prevent the activation of these receptors by histamine, thereby reducing the allergic response and alleviating the associated symptoms. 

In addition to its antihistaminic effects, azelastine may exhibit some anti-inflammatory properties, further contributing to its therapeutic action in allergic conjunctivitis. However, the exact mechanism of its anti-inflammatory effects has yet to be fully understood. 

Pharmacokinetics: 

Absorption 

azelastine ophthalmic is primarily absorbed through the conjunctival blood vessels of the eye after topical administration. It rapidly penetrates the ocular tissues, allowing for local therapeutic effects. 

Distribution 

After absorption, azelastine may be distributed throughout the ocular tissues, including the conjunctiva and cornea. The systemic distribution of azelastine following ocular administration is minimal, as the drug is primarily intended for local action in the eyes. 

Metabolism 

azelastine undergoes hepatic metabolism primarily via the cytochrome P450 enzyme system, particularly the CYP3A4 isoenzyme. The metabolism of azelastine results in the formation of metabolites, which are then further metabolized and eventually eliminated from the body. 

Elimination and Excretion 

The exact pathway of excretion of azelastine and its metabolites following ocular administration needs to be well-documented. However, based on general principles, it is likely that the drug and its metabolites are eliminated primarily through renal excretion and potentially through fecal excretion as well. 

Adminstartion

Administration: 

Ophthalmic administration 

The administration of azelastine ophthalmic eye drops typically involves the following steps: 

• Wash your hands thoroughly with soap and water before handling the eye drops. 
• Shake the bottle gently to ensure the contents are well mixed. 
• Tilt your head slightly and use your index finger to pull down the lower eyelid, creating a tiny pocket. 
• Hold the bottle of eye drops upside down (with the dropper tip pointing downwards) and place the tip close to your eye without touching it or any other surface. 
• Squeeze the bottle gently to instill the prescribed number of drops into the eye. Be careful not to squeeze too hard or to blink excessively during administration. 
• After instilling the drops, gently release the lower eyelid and close your eye. Do not blink or rub your eye immediately after administering the drops, as this can prevent the medication from being absorbed properly. 
• If you use eye drops in both eyes, repeat the process for the other eye. 
• If you are using any other eye drops or ointments, wait nearly 5 minutes before applying them to allow adequate time for absorption. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: azelastine ophthalmic 

Pronounced: [ a-ZEL-as-teen ] 

Why do we use azelastine ophthalmic? 

azelastine ophthalmic is primarily used to treat allergic conjunctivitis, also known as eye allergies. It is an antihistamine medication that helps to relieve symptoms associated with allergic reactions in the eyes. Some of the common uses of azelastine ophthalmic include: 

• Allergic Conjunctivitis: azelastine ophthalmic is effective in reducing symptoms associated with allergic conjunctivitis, such as itching, redness, watering, and swelling of the eyes caused by allergens like pollen, dust mites, pet dander, or other environmental irritants. 
• Seasonal Allergies: It can be used to manage symptoms of seasonal allergic conjunctivitis, which typically occurs during specific seasons when certain allergens are more prevalent, such as spring or fall. 
• Perennial Allergies: azelastine ophthalmic can also treat perennial allergic conjunctivitis, which refers to year-round allergies caused by allergens like dust, mold, or pet dander. 
• Ocular Itching: It effectively relieves itching in the eyes caused by allergic reactions.