I had a resident in a nursing home who had an extensive psych history including episodes of physical aggression and schizophrenia. They also would be extremely obsessive over various different things from time to time. There were followed closely by psychiatry. This patient was receiving a dose of Zyprexa (olanzapine) of 15 mg at bedtime. To help with the obsessive/compulsive disorder (OCD) the psychiatrist ordered Luvox (fluvoxamine) which is an SSRI, but is rarely used due to the potential for multiple drug interactions. Within a few days upon initiation of the Luvox, the patient was extremely lethargic and had a couple of falls. The most likely cause of this was an interaction where Luvox can significantly increase the blood levels of Zyprexa, leading to potential toxicity. If you ever see an order for Luvox, you must look for drug interactions!