High-dose loratadine exposure in a six-year-old child.

Loratadine is a long-acting antihistamine indicated for the treatment of seasonal allergic rhinitis and chronic idiopathic urticaria in patients 6 years of age and older. The literature contains little information on high-dose loratadine exposures; as a consequence, poison centers are unsure of the loratadine dose that can be managed with observation and the dose that requires treatment. We report an intentional ingestion of 300 mg loratadine by a 6-y-old child that resulted in minor elevation of blood pressure and heart rate when managed with supportive care only. Further studies and case series are needed before a minimum toxic dose can be established.