What is the recommended dosage and treatment regimen for Bilastine (Bilastine) 40 mg in adults with allergic rhinitis and urticaria?

Bilastine 40 mg is NOT the recommended dosage for adults with allergic rhinitis or urticaria

The standard approved dose of bilastine is 20 mg once daily in adults and adolescents ≥12 years of age, not 40 mg. 1, 2, 3

Standard Dosing Regimen

• Adults and adolescents ≥12 years: Bilastine 20 mg once daily 1, 2, 3
• Children 6 to <12 years: Bilastine 10 mg once daily 3
• Children <6 years: Not approved for use 3

Critical Administration Requirements

Bilastine must be taken on an empty stomach to ensure proper absorption:

• Take at least 1 hour before meals OR no sooner than 2 hours after meals 4, 5
• Food and fruit juice significantly slow absorption and reduce bioavailability 4
• This timing requirement is essential for therapeutic efficacy 1

Higher Dose Considerations (40 mg and Above)

While 40 mg is double the standard dose, bilastine has been studied at supratherapeutic doses:

• Doses up to 80 mg once daily (4× standard dose) have been safely used in chronic spontaneous urticaria 2
• The fourfold higher dose (80 mg) is recognized as an acceptable second-line treatment option for urticaria in international guidelines 2
• Bilastine is generally well tolerated even at above-standard doses 3
• However, 40 mg is not a standard recommended dose in any guideline or regulatory approval 1, 2, 3

Clinical Efficacy Profile

Bilastine 20 mg once daily demonstrates:

• Rapid onset of action with prolonged duration 2, 3
• Efficacy similar to cetirizine and desloratadine for allergic rhinitis symptoms 2, 5
• Efficacy similar to levocetirizine for chronic spontaneous urticaria 2
• Improvement in all nasal symptoms including nasal obstruction, plus ocular symptoms 4, 5
• Potentially longer duration of action than fexofenadine in some studies 2

Safety and Tolerability Advantages

• Minimal sedative potential compared to other second-generation antihistamines 2, 3
• No central nervous system penetration 3
• No cardiotoxicity or effects on cardiac conduction 1, 5
• No anticholinergic effects 3
• Does not affect driving ability or alertness at therapeutic doses 5
• Headache is the most frequently reported adverse effect 1

Drug Interaction Profile

• No significant metabolism in humans; excreted largely unchanged 2, 3
• Does not interact with cytochrome P450 system 1, 2, 3
• Very low potential for drug-drug interactions 2
• No dose adjustment required in renal or hepatic impairment 2, 3
• No dose adjustment required in elderly patients 3

Common Pitfalls to Avoid

• Do not prescribe 40 mg as a standard dose - this is not an approved regimen 1, 2, 3
• Do not allow patients to take bilastine with meals - absorption is significantly impaired 4
• Do not assume 40 mg provides better efficacy - the standard 20 mg dose has demonstrated comparable efficacy to other antihistamines 2, 5
• If standard dose is inadequate for urticaria, consider increasing to 80 mg (not 40 mg) as this is the dose studied and recognized in guidelines 2

Comparison to Guideline-Recommended Alternatives

While bilastine is not mentioned in older ARIA guidelines 6, it meets current criteria for second-generation antihistamines:

• Second-generation antihistamines are preferred over first-generation agents for allergic rhinitis 6
• Intranasal corticosteroids remain more effective than oral antihistamines for all symptoms of allergic rhinitis, especially nasal congestion 7, 8
• For inadequate response to antihistamines alone, adding intranasal corticosteroids provides better symptom control 7