Cetirizine – how much is too much?

Abstract

Background: Cetirizine hydrochloride is a commonly used over-the-counter antihistamine that may be prescribed in larger doses than are commonly used for allergic rhinitis for the management of chronic urticaria. Aim: To describe a case report of a paediatric patient who was treated with long-term and high-dose cetirizine. Clinical details: The patient developed a dystonic reaction probably as a result of the antihistamine overuse. The child involved in this case was taking the maximum daily dose regularly for several years. Outcomes: The parent was advised to cease treatment with (high dose and prolonged use) cetirizine and substitute a lower intermittent dose of an alternative antihistamine. Conclusion: Although cetirizine is widely considered a ‘safe’ medication, prescribers and pharmacists should be mindful that it has the potential to cause unacceptable side effects.