indapamide sr or indapamide 2,5mg

Dear Mr./Mrs. X,

My grandmother was prescribed slow realise indapamide by 1,5mg (one tablet, 2 times a week), but there was just indapamide by 2,5mg in the pharmacie and the pharmacist told her to take them instead of prescribed. Will there be the same effect with those she bought as with the prescribed one? The doctor gave them for their diuretic, not antihypertensive effect.

Thank you in advance