Antihistamine (H1, second-generation, non-sedating) Pregnancy: Loratadine has the largest pregnancy dataset and is preferred; desloratadine likely equally safe but less data.

Desloratadine

Brand names: Neoclarityn, Aerius

Adult dose

Dose: 5 mg OD

Route: Oral

Frequency: Once daily

Max: 5 mg/day (up to 4× off-label in chronic spontaneous urticaria under specialist)

Take with or without food. Active metabolite of loratadine — equivalent efficacy with marginally less drowsiness.

Paediatric dose

Route: Oral

Frequency: Once daily

1–5 yrs: 1.25 mg OD (oral solution 0.5 mg/ml — 2.5 ml). 6–11 yrs: 2.5 mg OD. ≥12 yrs: 5 mg OD.

Dose adjustments

Renal

eGFR <30: alternate-day dosing (5 mg every other day).

Hepatic

Severe: alternate-day dosing.

Clinical pearls

Active metabolite of loratadine — pharmacologically very similar; choice usually based on cost and formulation availability.
Excellent safety in elderly and polypharmacy — minimal CYP interactions, no clinically significant QT effect.
First-line for allergic rhinitis (BSACI 2017) and chronic urticaria (EAACI 2022) — guidelines support up-dosing to 4× standard dose for refractory urticaria.
Marginally less sedating than cetirizine in some head-to-head studies — useful when cetirizine causes drowsiness.
Children: oral solution useful in pre-school age; orodispersible tablets for older children.

Contraindications

Hypersensitivity to desloratadine or loratadine
Children <1 year (limited data)

Side effects

Headache
Dry mouth
Fatigue, drowsiness (very low — comparable to placebo)
Pharyngitis, dyspepsia, myalgia (uncommon)
Rarely: tachycardia, palpitations

Interactions

Minimal — does not significantly inhibit or induce CYP enzymes; no QT effect at therapeutic dose

Monitoring

Symptom response at 4 weeks; consider up-dosing in CSU under specialist

Reference: BNFc; BNF 90; SmPC Neoclarityn / Aerius; 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

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

Pathways