Folate Study in Men With Advanced Prostate Cancer

The researchers hope to learn if Trimethoprim, 150mg taken daily for 3 months, is a safe and effective way to reduce folate levels at time of Androgen Deprivation Therapy (ADT) in men with advanced prostate cancer. This study will help find out what effects, good and/or bad, this drug has on people who take it and on its effect on the disease. The safety of this drug in humans has been tested in prior research studies; however, some side effects may not yet be known.

While taking part in this study, participants will be asked to attend approximately 4 to 7 visits - depending on what randomized arm they are in - with the researchers or study staff. It may be necessary for participants to return to the hospital/clinic every 1-3 months as part of their regular care. Research procedures will be completed at the same time as these routine standard of care visits. Participants will be asked to stop taking any supplements or medications containing folic acid or potassium prior to enrolling in the study.