There are lots of different opinions on this. But if you go to the web site of the Urologist in Chicago who pretty much discovered the the use of the PSA test in the 1990's, you will find that he suggests using ED drugs immediately after surgery.
My urologist waited until the catheter was out at two weeks post open surgery and then had me start on Viagra with a daily dose. I was on ED drugs prior to the surgery due to hypertension and had saved up pills. Once I found this web site and ADC, I switched to getting the drugs from ADC.
The ED drugs didn't help that much, so at 3 months I started using a VED. Then at 6 months, I went to Injections.
I would not wait very long, just my own personal opinion....
Age 60, PSA 2007 4.1, PSA 2008 10.0
Diagnosed April 2008, Biopsy: 6 of 12 cores positive, Gleason 4 + 5 = 9
CT and Bone Scan negative, Open surgery at Shawnee Mission Medical Center May 21, 2008
Right side nerves spared, Radical prostatectomy and lymph node dissection
Cather removed on June 3rd, totally dry on July 9th, pT2c, lymph nodes negative
PSA Sept 28, 2008 0.00, PSA Jan 22, 2009 0.00, PSA June 29, 2009 0.00
PSA Sept 2009 0.00, PSA Dec 21, 2009 0.02, PSA March 29, 2010 0.03
ED Status- Currently using Trimix, Levitra daily for increased blood flow.
Noctural Erections have completely returned on a nightly basis, same hardness as before.
Stopped the injections except for "Fun" weekends. Really don't need them anymore.