Welcome to healthcare Magic!
A BP of less than 160 mmHg (systolic) is usually acceptable unless the patient has cardiac failure, kidney
disease or diabetes
when it should not cross 130 mmHg.
I would suggest that he should start an antihypertensive in consult with an experienced physician to cut down on the BP fluctuation.
Usually the antihypertensives are taken in the morning and BP should be measured just prior to that to see how is the overall control rather than seeing the best values after giving the drugs and suffering the worst outcome when not monitoring the real range.
Wish you a great health!