Loratadine (Claritin)

Yesterday I also learned a bit about the biochemical/orgo basis for how Claritin works, during the orgo II drug poster sessions. I learned that Claritin is a second generation antihistamine, which means that it is a non-sedative antihistamine (while first generation antihistamines, such as Benadryl, are sedative). But it was so cool because the presenter, Mariya, was able to tell us the molecular reason for why Claritin was non-sedative. Basically, there is an added ester group on one end of the molecule that then does not allow it to cross the blood-brain barrier due to its newfound polarity. Since it can’t cross this barrier,  it can’t stimulate a drowsy response.