What are the indications, recommended dosing and administration, contraindications, adverse effects, drug interactions, and pregnancy/lactation considerations for bilastine?

Bilastine: Clinical Overview

Indications

Bilastine is indicated for the treatment of allergic rhinoconjunctivitis (seasonal and perennial) and chronic urticaria in adults and children aged 6 years and older. 1, 2

• Approved for both nasal and ocular symptoms of allergic rhinitis 3
• Effective for managing wheals and itching in chronic spontaneous urticaria 1
• Demonstrates efficacy similar to cetirizine and desloratadine for seasonal allergic rhinitis 1
• Shows comparable efficacy to levocetirizine in chronic urticaria 1

Recommended Dosing and Administration

Standard Dosing

• Adults and adolescents ≥12 years: 20 mg orally once daily 3, 4
• Children aged 6 to <12 years: 10 mg orally once daily 5, 4

Critical Administration Requirements

• Must be taken on an empty stomach—avoid administration at meal times 3
• Food interferes with absorption and reduces bioavailability 3
• Take either 1 hour before or 2 hours after meals

Dose Escalation for Refractory Urticaria

• Up to 4 times the standard dose (80 mg once daily in adults) can be safely used for inadequate symptom control 1, 2
• This fourfold dosing is recognized as an acceptable second-line treatment option in international urticaria guidelines 1
• Well tolerated even at supratherapeutic doses 2

Special Populations

• No dose adjustment required in renal impairment 1, 4
• No dose adjustment required in hepatic impairment 1, 4
• No dose adjustment required in elderly patients 4

Contraindications

There are no absolute contraindications listed for bilastine. 1

• Hypersensitivity to bilastine or any excipients would be a standard contraindication (general medical knowledge)

Adverse Effects

Bilastine has a safety profile very similar to placebo with minimal adverse effects. 2, 3

Most Common Adverse Effects

• Headache is the most frequently reported adverse effect 3
• Incidence of treatment-emergent adverse events in children (6-11 years) is not significantly different from placebo 5

Key Safety Features

• No significant sedation or CNS effects—does not penetrate the central nervous system 3, 4
• No cardiotoxicity—does not alter heart rate or cause QT prolongation 1, 3
• No anticholinergic effects 4
• Sedative potential is less than other second-generation antihistamines 1

Drug Interactions

Bilastine has very low potential for drug-drug interactions. 1, 4

Pharmacokinetic Profile

• Does not interact with the cytochrome P450 system 1, 4
• Does not undergo significant metabolism in humans—excreted largely unchanged 1, 3
• Elimination is through kidneys and feces with a 14-hour half-life 3

Practical Considerations

• The lack of CYP450 interaction makes bilastine particularly suitable for patients on multiple medications 4
• No clinically significant drug interactions have been identified in clinical trials 1

Pregnancy and Lactation Considerations

Pregnancy

There are no adequate safety data for bilastine use during pregnancy—it should be avoided, especially during the first trimester. 6, 7

• Preferred alternatives during pregnancy include:
  • Cetirizine or loratadine (FDA Pregnancy Category B with better documented safety profiles) 6, 7
  • Chlorphenamine (long safety record, often chosen by UK clinicians) 6, 7
• Levocetirizine (the active enantiomer of cetirizine) should also be avoided in first trimester due to limited safety data 6
• The first trimester is the most critical period due to organogenesis 6

Lactation

Safety data for bilastine during breastfeeding are limited—safer alternatives should be used. 8

• Preferred antihistamines during breastfeeding:
  • Cetirizine 10 mg once daily 8
  • Loratadine 10 mg once daily 8
• These alternatives have minimal infant exposure through breast milk 8
• Alternative second-generation options include desloratadine, fexofenadine, and levocetirizine 8

Clinical Advantages

Efficacy Profile

• Rapid onset of action with prolonged duration 1, 2
• Potentially longer duration of action than fexofenadine based on Vienna Chamber studies 1
• Improves health-related quality of life in patients with allergic rhinitis and urticaria 2, 4

Pharmacokinetic Advantages

• Pediatric pharmacokinetics (ages 6-11 years) show similar exposure to adults: median pediatric/adult ratios for AUC₀₋₂₄ and Cmax were 0.93 and 0.91, respectively 5
• Highly selective for H1 histamine receptor 1
• Scarcely metabolized, reducing risk of metabolic drug interactions 3

Common Pitfalls to Avoid

• Do not administer with food—this is the most common prescribing error that reduces efficacy 3
• Do not use as first-line in pregnant or breastfeeding women—choose cetirizine or loratadine instead 6, 7, 8
• Do not hesitate to increase dose up to 4-fold in refractory urticaria—this is safe and guideline-supported 1, 2
• Do not assume dose adjustment is needed in renal/hepatic impairment or elderly—bilastine requires no adjustment 1, 4