Low Dose Naltrexone (LDN) for Management of Fatigue in Prostate Cancer Patients on Androgen Deprivation Therapy (ADT)

The study is being done to see if a small daily dose of naltrexone (LDN, 3 mg pill) can help reduce tiredness (fatigue) in men with prostate cancer. All men in this study are being treated with hormone therapy (also called androgen deprivation therapy, or ADT). Some may also be taking newer hormone medicines such as apalutamide, daralutamide, enzalutamide, or abiraterone.

Inclusion Criteria * Histologically or cytologically confirmed biochemical recurrence and on ADT for at least 3 months. Metastatic castrate-sensitive and castrate-resistant prostate cancer on ADT with or without novel hormonal therapy like apalutamide, darolutamide, enzalutamide and abiraterone. * Initiation of hormonal ablative therapy within 3 months of registration. * ECOG performance status \3,000/μL * absolute neutrophil count \>1,500/μL * platelets \>100,000/μL * total bilirubin within normal institutional limits * AST(SGOT)/ALT(SGPT) \45% * FACIT-F score \< 43 on screening * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria * Prior chemotherapy received in the last three months. * Patients currently on PARP inhibitors. * Currently taking or have taken within 10 days of enrollment. * Patients may not be receiving any other investigational agents. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to Naltrexone or other agents used in the study. * History of other malignancies other than nonmelanoma skin cancer, unless in complete remission and off therapy for that disease for at least 5 years. * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, history of congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. * Any Patient with acute hepatitis and liver failure are excluded.