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

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. 

A cycloheptathiophene blocker of histamine H1 receptors and release of inflammatory mediators. It has been proposed for the treatment of asthma, rhinitis, skin allergies and anaphylaxis.