An unusual case of cyproheptadine (Periactin) overdose in an adolescent female

A 13-year-old female ingested an acute overdose of cyproheptadine hydrochloride (Periactin) and presented for treatment. She manifested all the classic signs and symptoms of an acute antihistamine overdose, including psychosis, except for miotic, minimally reactive pupils. The patient was supportively managed. All sequelae of the ingestion resolved within four days, and the child was released from the hospital. We discuss the unusual presentation of miotic pupils in an acute cyproheptadine overdose.