I tried Claritin for a little while (nasty tree pollen allergy, especially cedar, for me) and I didn't like it. The allergist I saw put me on Allegra instead. It doesn't work the same way as Claritin so it doesn't dry you out, make you jittery or put you to sleep. Regular antihistimines really get to me, I get every side effect they list, but I don't get any side effects off of Allegra. On the other hand, this year it didn't really take care of the symptoms either.... (Allegra + Flonase and I was still snot city) so he gave me Singulair too, but as usual I waited a little too long and my symptoms were diminishing by the time I got an appointment, so I'll have to wait until next spring to see how well it really works. The only side effect I get from the Singulair, is that I seem to sleep more soundly, which isn't necessarily a bad thing.