What would happen if I took 2 Claritin?

I may have just taken 2 Claritin just now instead of 1, although I'm not sure. It was really stupid, I forgot whether I had taken one yet or not so I took another. Anyway, I'm wondering if anyone else has done this and what happened? The bottle says to only take one (10 mg) every 24 hours but I figure you must need a lot more than two to have any real adverse effects...right?