Hi there ~
I understand your concerns. There is no cause for concern from using the medication levocetrizine, especially the ones that you mention. I do believe that cetrizine can cause drowsiness
, however levocetrizine does not cause any side effect that you mention. There are no memory effects of the medication as well. Please consult a local doctor for any problems regarding memory that you may have that are not related to the medication, but may be an underlying medical condition.
I hope this helps. Take care and have a lovely day!