Need to take 30 mg ER imdur for angina. Would it cause low blood pressure. How effictive it is vs regular isosorbide regular release on blood pressure?

Nitrates. Both may cause some drop in blood pressure but usually not very much. Nitrates are not typically used for treatment of hypertension. The effects of the short and long acting isosorbide mono nitrate are similar; the difference is how often it has to be taken, i.e. Once vs. Twice a day.