Taking Zyprexa (olanzapine) (2.5ng) before bed. Waking up feeling really tired, weak, shaky and sometimes dizzy. Is this normal and when will it pass?

Side effects. It is unusual to experience these side effects. In fact, 2.5 ia a low, usually a start up dosage. I suggest to consult your prescriber to switch you to another equivalent medication. However, this is more pertinent if this is a persistent problem or just a temporary reaction to this med.