Despite tremendous progress in prostate cancer therapy, a significant proportion of prostate cancer patients will develop drug resistance and succumb to their disease. We require new therapies that can be incorporated quickly into clinical practice. By investigating FDA approved, and well tolerated agents, our goal is to re-purpose them in the clinic to improve the efficacy of current therapies and overcome drug resistance in prostate cancer patients. We will investigated how effective antihistamine drugs commonly used to treat allergies can target lysosomes or “garbage cans” of the cells. We want to know if they can kill prostate cancer cells, and how they are killing the cells. We will then investigate how effective these drugs are when combined with standard therapies. Our ultimate goal is to take these FDA approved drugs in combination with conventional chemotherapies to clinical trials for patients with advanced prostate cancer.