Suggest Remedy For Fluctuation In Bp

Hi there I have question regarding my mother high blood pressure.she is 70 years old and suffer from high blood pressure for more than 35 years.currently she take one concor 5 plus tablet in the morning and one Coversyl 5mg tablet night.i discovered recently that her blood pressure start to be less than normal (average 116 h, 63 l, 85 beat) and she feels dizzy so, i stopped Coversyl 5mg and stick to one concor 5 plus tablet in the morning.average changed now to (average 133 h, 67 l, 84 beat) but the last 3 readings average of today is (147 h, 71 l, 87 beat) i'll keep checking for another one or two days but if it keeps on that rage or higher should i get back to Coversyl 2.5mg instead of 5mg in addition to concor 5 plus?thanks for your time.