Bilastine: Uses, Interactions, and Mechanism of Action

Bilastine is a second-generation antihistamine widely prescribed to manage allergic conditions such as hay fever (allergic rhinitis) and chronic urticaria (hives). Known for its non-sedating effects and rapid onset of action, Bilastine has become a preferred choice for both short-term and long-term allergy management.

In this blog, we’ll dive into the key aspects of Bilastine, including its uses, drug interactions, and mechanism of action.

What Is Bilastine?

Bilastine is a non-sedating H1-antihistamine, available in oral tablet and oral solution forms. It was developed to provide effective relief from allergic symptoms without causing drowsiness, which is a common side effect of older antihistamines like diphenhydramine or hydroxyzine.

It is commonly marketed under various brand names, such as:

• Bilaxten
  
  

• Blexten
  
  

• Zilas
  
  

Uses of Bilastine

Bilastine is used to treat several allergic conditions, including:

1. Allergic Rhinitis

This includes both seasonal allergic rhinitis (hay fever) and perennial allergic rhinitis. Bilastine helps relieve symptoms like:

• Sneezing
  
  

• Nasal congestion
  
  

• Itchy nose
  
  

• Runny nose
  
  

• Itchy or watery eyes
  
  

2. Chronic Idiopathic Urticaria

Bilastine is effective in treating chronic hives by reducing:

• Red, raised, itchy welts
  
  

• Swelling
  
  

• Irritation
  
  

Off-label and Investigational Uses:

While not officially approved for all indications, Bilastine has shown potential in managing:

• Allergic conjunctivitis
  
  

• Food allergies (under study)
  
  

• Atopic dermatitis (as part of multi-drug therapy)
  
  

Mechanism of Action of Bilastine

Bilastine works by selectively blocking histamine H1 receptors in peripheral tissues.

Here’s how it functions:

1. Histamine Release: During an allergic reaction, histamine is released by mast cells.
   
   

2. H1 Receptor Binding: Histamine binds to H1 receptors, causing symptoms like itching, swelling, and runny nose.
   
   

3. Bilastine Action: Bilastine competitively binds to the H1 receptors, preventing histamine from attaching and exerting its effects.
   
   

4. Result: This blockade reduces allergy symptoms without crossing the blood-brain barrier significantly, thus avoiding sedation.
   
   

Key Pharmacological Properties:

• High selectivity for peripheral H1 receptors
  
  

• Rapid onset of action (typically within 1 hour)
  
  

• Long duration of action (about 24 hours)
  
  

• Minimal CNS penetration (low risk of drowsiness)
  
  

Bilastine Drug Interactions

Though generally safe, Bilastine can interact with certain substances:

1. Food and Juice Interactions

• Grapefruit juice, apple juice, and orange juice may reduce Bilastine absorption by inhibiting intestinal transporters.
  
  

• Recommendation: Take Bilastine on an empty stomach, at least 1 hour before or 2 hours after food or juice.
  
  

2. P-glycoprotein Inhibitors

Drugs like ketoconazole, erythromycin, and cyclosporine can increase Bilastine plasma levels by inhibiting P-glycoprotein, which transports Bilastine.

3. Alcohol and CNS Depressants

Although Bilastine is non-sedating, combining it with alcohol or other CNS depressants might still impair alertness in sensitive individuals.

4. Other Antihistamines

Avoid combining with other antihistamines unless prescribed, as it may increase the risk of side effects without additional benefit.

Dosage and Administration

• Adults and children (≥12 years): 20 mg once daily
  
  

• Children (6–11 years): Often a lower dose or oral solution
  
  

• Should be taken 1 hour before or 2 hours after food or fruit juice

Advantages of Bilastine

• Non-sedating
  
  

• No significant liver metabolism (safe for patients with mild hepatic issues)
  
  

• Minimal drug-drug interactions
  
  

• Safe for long-term use in chronic allergies
  
  

Who Should Avoid Bilastine?

• People with severe kidney impairment (dose adjustment may be required)
  
  

• Those on interacting medications (e.g., strong P-gp inhibitors)
  
  

• Children under 6 years (use with pediatric guidance)
  
  

Always consult a healthcare provider before starting any new medication.

Final Thoughts

Bilastine is a modern, well-tolerated antihistamine that offers effective relief from common allergic symptoms without the drowsiness associated with older antihistamines. Its once-daily dosing, fast onset, and low risk of sedation make it a top choice for many patients and clinicians alike.

If you suffer from chronic allergies or urticaria, talk to your doctor about whether Bilastine could be a good fit for your treatment plan.

URL: For more information, visit Vasista Pharma: Bilastine: Uses, Interactions, and Mechanism of Action