Phenyltoloxamine is an antihistamine drug that is used to relieve allergy symptoms such as sneezing, runny nose, and itching. However, there are several synonyms or alternative names for this drug. Some of the commonly used synonyms for phenyltoloxamine include Oprea1, Histyn2, Allergex3, Prulet4, and Allerest5. Each of these names indicates the same drug, phenyltoloxamine, and its medicinal properties. Although the synonym names may vary, the active ingredient of the drug remains the same. Therefore, patients using the drug should ensure they verify the alternative names before purchasing or administrating it to avoid any confusion or overdose.