The first undetectable PSA is the one that brings the biggest sigh of relief. One of the reasons, among many, that we selected prostatectomy for treating prostate cancer is that the PSA drops to zero right away.
Each of the oral ED meds has its own dose strength. You should check with your urologist to see if you should take a half or a whole pill with the Levitra.
There is some sick humor that only someone with ED following prostate cancer treatment can fully appreciate in being given an empty box of Cialis.
I can imagine your unclouded happiness in getting the terrific news of your good PSA results--been there, done that!
Be well and live long...Tim