Cetirizine-Associated Delusions and Depression in an 18-Year-Old Woman

Cetirizine is a second-generation H1 histamine receptor antagonist that is commonly used for symptomatic relief of hay fever and other allergies and can be combined with pseudoephedrine hydrochloride, a decongestant. The most common adverse effects include headache, nausea, nasopharyngitis, vomiting, and coughing. To report on an adolescent 18-year-old woman who developed delusional thinking and depression after starting treatment with cetirizine. We report on an adolescent 18-year-old woman who developed delusional thinking and depression after starting treatment with cetirizine. Once cetirizine was discontinued, the patient returned to her clinical baseline. Physicians need to be aware of the potential psychiatric adverse effects associated with cetirizine.