admin answers:
I really should know the answer to this given my job and I was married to a urologist, but I cannot give you an exact answer. There should be enough time to allow the prostate to recover from the irritation and inflammation the biopsy causes as this would give a false positive result. So I am guessing 6-8 weeks.
If the biopsy is positive there really is no need for another PSA anytime soon, unless he is choosing watchful waiting as his treatment. If it is negative, but his PSA is slowly rising it will likely be checked again in 6 months to 1 year.
Source: http://www.myprostatecancerstory.com/2011/08/bleeding_after_prostate_biopsy/