Olanzapine (Zyprexa^®) is a drug that is licensed to treat schizophrenia and bipolar disorder. This medication works by blocking or lessening the effects of several chemicals in the brain. However, olanzapine is not a cure for bipolar disorder or schizophrenia; it only controls the symptoms of these conditions. Olanzapine comes in tablet form and is usually taken once a day. If you happen to overdose on olanzapine, seek medical attention immediately. Symptoms of an olanzapine overdose could include agitation or aggressiveness, changes in speech or language, a fast heart rate (tachycardia), and sleepiness or passing out.