No.

Prerenal azotemia occurs when BUN is elevated disproportionately to serum creatinine, indicating a non-renal reason for at least part of the BUN increase. In pure renal problems, BUN and creatinine usually rise together and preserve the same ratio. Normally BUN/creatinine is less than 15. Prerenal azotemia generally shows a BUN/creatinine ratio of greater than 15.

In this case BUN is 50 and creatinine is 4. 50 is less than 4 x 15 ( = 60), so this is not a case of prerenal azotemia.