Phenelzine Sulfate in Treating Patients With Non-metastatic Recurrent Prostate Cancer

This phase II trial studies phenelzine sulfate in treating patients with prostate cancer that has not spread to other parts of the body and has come back. Phenelzine sulfate is a type of antidepressant that works by decreasing the amount of a protein called monoamine oxidase (MAO). MAO drugs may have an anticancer effect in prostate cancer.

PRIMARY OBJECTIVES: I. To assess the proportion of patients with biochemical recurrent prostate cancer (BCR-PC) treated with phenelzine (phenelzine sulfate) who achieve a prostate-specific antigen (PSA) decline of \>= 50% from baseline. SECONDARY OBJECTIVES: I. To monitor potential toxicities and/or beneficial effects on quality of life of phenelzine in prostate cancer patients. II. To assess time to radiographic disease progression for patients with recurrent prostate cancer treated with phenelzine. III. To collect blood and other samples to study the relationship between MAO activity and prostate cancer. OUTLINE: Patients receive phenelzine sulfate 30 mg by mouth (PO) twice daily (BID) (starting dose of 15 mg daily escalated to 30 mg BID over 16 plus or minus 5 days). Patients who have been treated at 30 mg BID for over 3 cycles with resolution of any and all toxicities to grade \< or = 1 may increase the dose to a maximum of 45 mg BID at the discretion of the treating investigator. Treatment may continue in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for up to 3 years.