The main third-generation antihistamines are dicloretadine, dicloretadine citrate, levocetirizine, and fexofenadine. Third-generation antihistamines, also known as second-generation new antihistamines, are derivatives or metabolites of second-generation antihistamines (cetirizine, loratadine, etc.), and their main effects are anti-inflammatory and anti-allergic. Compared with second-generation antihistamines, third-generation antihistamines have fewer adverse effects. Some studies have shown that third-generation antihistamines have milder central nervous system adverse effects such as sedation and drowsiness, and relatively no or minimal cardiac adverse effects. In addition, third-generation antihistamines have the advantages of faster oral absorption and stronger drug effects compared with the previous two generations. At present, the third generation of antihistamines has a broader application prospects, but the choice of drugs still need to be under the guidance of a physician.