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

Acrivastine

Brand names: Benadryl Allergy Relief

Adult dose

Dose: 8 mg TDS

Route: Oral

Frequency: Three times daily

Max: 24 mg/day

Onset within 30 minutes — useful for prn allergy attacks.

Dose adjustments

Renal

Avoid if eGFR <50 ml/min — renally excreted.

Clinical pearls

Faster onset (~30 min) than cetirizine or loratadine — useful for situational allergic symptoms (e.g., known cat exposure, hayfever flare).
Three-times-daily dosing limits adherence vs once-daily second-generation alternatives — typically reserve for prn use.
Available OTC as Benadryl Allergy Relief — note this differs from US Benadryl (diphenhydramine, first-generation).
Less sedating than chlorphenamine but more so than fexofenadine — counsel against driving until effect known.

Contraindications

Severe renal impairment (eGFR <50)
Children under 12 years
Hypersensitivity to triprolidine (parent compound)

Side effects

Somnolence (low — second-generation, but more than cetirizine/loratadine)
Headache
Dry mouth
Fatigue

Interactions

Alcohol and other CNS depressants: additive sedation
MAOIs: theoretical risk — caution

Reference: BNF 90; SmPC Benadryl Allergy Relief; BSACI Rhinitis Guideline 2017; NICE CKS Allergic Rhinitis. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways