Desloratadine is a tricyclic H₁ antagonist that is used to treat allergies. It is an active metabolite of loratadine.

Levocetirizine is an antihistamine used for the treatment of allergic rhinitis and long term hives of unclear cause. It is less sedating than older antihistamines. 

Loratadine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes and runny nose. Loratadine is used to treat sneezing, runny nose, watery eyes, hives, skin rash, itching and other cold or allergy symptoms.

Diphenhydramine is an antihistamine mainly used to treat allergies. It can also be used for insomnia, symptoms of the common cold, tremor in parkinsonism and nausea.