Antihistamine (H1, second-generation) Pregnancy: No information available on effects during human pregnancy or lactation; there are no adequate and well-controlled studies in pregnant women. Should not be used during pregnancy or lactation unless the potential benefit to the mother outweighs any possible risk to the developing foetus/nursing infant.

Acrivastine

Brand names: Benadryl Allergy Relief

Acrivastine is a non-sedating second-generation H1 antihistamine used for the symptomatic relief of allergic rhinitis and urticaria.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: One 8 mg capsule

Route: Oral

Frequency: As necessary, up to three times a day

Max: SPC states 'as necessary up to three times a day' (i.e. no more than three 8 mg doses per day); no separate maximum daily milligram figure is stated

SPC posology applies to adults and children 12-65 years. Elderly (over 65): no specific studies have been carried out; until further information is available acrivastine should NOT be given to elderly patients. Paediatric population: safety and efficacy in children under 12 years has not yet been established. Renal dysfunction: contraindicated in severe renal impairment. Source product: Acrivastine 8 mg Capsules, hard (UK SPC).

Dose adjustments

Renal

Contraindicated in severe renal impairment. Renal excretion is the principal route of elimination; until specific studies have been carried out acrivastine should not be given to patients with significant renal impairment. Patients with renal impairment should consult a physician before use. No dose-reduction schedule is given in the SPC.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to acrivastine, to triprolidine, or to any of the excipients
Severe renal impairment (product is contraindicated); acrivastine should not be given to patients with significant renal impairment as renal excretion is the principal route of elimination

Side effects

Somnolence (very common)
Dizziness (common)
Dry mouth (common)
Rash (frequency not known)
Hypersensitivity, including dyspnoea and face swelling (frequency not known)

Interactions

Alcohol, sedatives, tranquillisers and other CNS depressants - concomitant administration may produce additional impairment of mental alertness in some individuals
Ketoconazole, erythromycin and grapefruit juice - no data demonstrate an interaction with acrivastine, but caution is advised due to known interactions between these compounds and other non-sedating antihistamines

Clinical monograph

How it works

It selectively blocks peripheral histamine H1 receptors, antagonising the effects of histamine released during allergic responses.

Prescribing in practice

Although classed as non-sedating, it can still cause drowsiness in some patients, who should be cautioned about driving or operating machinery until its effects are known.
It is renally excreted, so caution and dose review are advised in significant renal impairment.
Short duration of action means it is typically taken several times daily rather than once daily.

Monitoring

Routine laboratory monitoring is not required; assess symptom control and tolerability clinically.

Counselling the patient

Take to relieve symptoms and report if drowsiness occurs.
Avoid alcohol, which may add to any sedative effect.
Seek advice if symptoms persist despite regular use.

Evidence & guidelines

Second-generation antihistamines are recommended by NICE as first-line pharmacological treatment for allergic rhinitis.

Reference: SmPC Benadryl Allergy Relief; BSACI Rhinitis Guideline 2017; NICE CKS Allergic Rhinitis; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways