Common and Serious Side Effects of Zyprexa. The more common symptoms might include restlessness, depression, drowsiness, dizzinessZyprexa and its generic, olanzapine, are available in a tablet (2.5 milligrams (mg), 5 mg, 7.5 mg, 10 mg, 15 mg and 20 mg) and a disintegrating tablet ( 5...