Is there an drug interaction with haldol, (haloperidol) olanzapine, zyprexa and the antidepressant wellbutrin?

Yes there are: Zyprexa (olanzapine) is the trade name for Olanzapine so you only have 3 unique drugs listed though some would argue that brand & generic named drugs are technically 2 distinct forms of chemical compounds. There are several SIGNIFICANT reactions (heart rhythm, sedation, neurological issues) that could occur with these drugs so you should talk things over with your doctor if there are concerns or side effects.

Drug interactions: Well Zyprexa is the brand name for olanzapine. Haldol and Zyprexa are two different generations of psychosis medications. You can use a drug interaction checker whenever you have questions about drug-drug interactions or drug - food interactions. Here is 1 option (Drugs.Com): https://www.drugs.com/drug_interactions.php Your pharmacist is also a good source of info.