I take 20 mg benazripril in the am for hbp my heart rate resting is 50 to 64 bmp is this low, my dr.hasn't mentioned any concerns?

Heart rate: There is no problem as your heart rate is normal but may become a little slower as your blood pressure became more normal

Maybe normal: A heart rate in the 50's -60's maybe normal, especially if your physically fit. Marathon runners often have heart rate down to the 40's. The time to get concerned is if there are symptoms of dizziness, weakness, shortness of breath etc. A highly variable rate may also indicate need for further evaluation.

Slow heart: Normal heart rates at rest vary from 55 -90 with 72 being average. 50/min may be OK for you unless you notice easy fatigue, shortness of breath with exertion or lightheadedness. Your physician,who knows all your findings, is best qualified to advise you.