Levocetirizine hydrochloride

How it works

It is a selective peripheral histamine H1-receptor antagonist that blocks histamine-mediated allergic responses such as itch, sneezing, rhinorrhoea, and wheal formation.

Prescribing in practice

• Although classed as non-sedating, drowsiness can still occur and patients should assess their response before driving or operating machinery, and be cautious with alcohol and other sedatives.
• Dose reduction or extended dosing interval is required in renal impairment; consult the SPC for adjustment and for paediatric dosing use a children's formulary.
• Generally avoided where there is significant renal impairment without adjustment; review prescribing references for contraindications.

Monitoring

Routine laboratory monitoring is not required; assess symptom control and any sedative effect, particularly in renal impairment.

Counselling the patient

• Most people are not affected, but if it makes you drowsy avoid driving and avoid alcohol.
• It can be taken to relieve ongoing allergy symptoms; take it regularly during your allergy season if advised.

Evidence & guidelines

Second-generation antihistamines such as levocetirizine are recommended as first-line pharmacological treatment for allergic rhinitis and chronic urticaria in NICE and international allergy guidance.