Prostate volume 80 cc , psa 4.5 - pvr 105 ml- 58 years old . currently taking urimax d . what should be further course of action?

Depends on more info: There is limited information in this question. I would be interested to know about symptoms and psa numbers in past. Based just on the information provided, I would recommend a prostate biopsy to rule out prostate cancer. If the biopsy is negative, you may consider a medication such as finasteride or dutasteride to reduce the size of the prostrate. Of course, there are side effects with meds.