- Participants must not have a history of prostate cancer, prior surgery on the prostate, kidney failure, or taking furosemide (Lasix), warfarin (Coumadin), or hormone medications. Individuals taking medicine for their BPH must stop them for one month (prazosin, terazosin (Hytrin), doxazosin (Cardura), tamsulosin (Flomax)) or six months (saw palmetto, finasteride (Proscar or Rogaine)) prior to entering the study.