Antihistamine (H1, second-generation, non-sedating) Pregnancy: Avoid — limited human data. Loratadine or cetirizine preferred in pregnancy (largest dataset).

Bilastine

Brand names: Ilaxten

Adult dose

Dose: 20 mg OD on an empty stomach (≥1 hr before or 2 hr after food/fruit juice).

Route: Oral

Frequency: Once daily

Max: 20 mg/day

Food and fruit juices reduce absorption by 30%. Timing matters more than for other antihistamines.

Paediatric dose

Route: Oral

Frequency: Once daily

≥6 yrs and ≥20 kg: 10 mg OD (orodispersible tablet). ≥12 yrs: adult dose 20 mg OD.

Dose adjustments

Renal

No adjustment in renal impairment.

Hepatic

No adjustment.

Clinical pearls

Among the least sedating second-generation antihistamines — does not cross BBB significantly; safe for pilots, drivers (no cognitive impairment in studies vs cetirizine/desloratadine).
No dose adjustment in renal or hepatic impairment — useful for elderly polypharmacy.
Does NOT prolong QT — favourable cardiac safety profile compared with first-generation antihistamines.
Empty-stomach dosing is the only practical drawback — counsel patient explicitly about timing.
Reasonable second-line if cetirizine or fexofenadine ineffective for chronic urticaria; sometimes used at off-label up-dosing under specialist (4× daily dose tested in CSU studies).

Contraindications

Hypersensitivity to bilastine or excipients
Children <6 years

Side effects

Headache
Drowsiness (very low — comparable to placebo in trials)
Fatigue
Dry mouth
Rarely: dyspepsia, dizziness

Interactions

P-gp inhibitors (ketoconazole, erythromycin, ciclosporin, ritonavir): ↑ bilastine exposure — caution
Food and grapefruit juice: ↓ absorption by 30% — take on empty stomach
Alcohol: minimal additive sedation

Monitoring

Symptom response at 4 weeks

Reference: BNFc; BNF 90; SmPC Ilaxten; BSACI Rhinitis Guideline 2017; EAACI/GA²LEN Urticaria Guideline 2022. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Desloratadine · Antihistamine (H1, second-generation, non-sedating)

Pathways