Perindopril + Indapamide

Perindopril is a nonsulphydryl ACE inhibitor used to treat hypertension. After it is taken by mouth, it is quickly hydrolysed to perindoprilat, its main active metabolite. ACE converts angiotensin I into angiotensin II, which narrows the blood vessels (a vasoconstrictor). Angiotensin II also stimulates the adrenal cortex to secrete aldosterone. When ACE activity is inhibited, angiotensin II levels fall, so there is less vasoconstriction and less aldosterone secretion. The drop in aldosterone may cause a small rise in serum potassium. Lower angiotensin II also means the body loses its negative feedback on renal renin secretion, and this raises plasma renin activity. Perindopril may also interfere with the breakdown of bradykinin, a vasodepressor peptide. It is not known whether this effect adds to the therapeutic action of perindopril. The way perindopril lowers BP appears to come mainly from suppression of the RAAS.

Indapamide is a sulphonamide derivative with an indole ring, and it is pharmacologically related to the thiazide group of diuretics. It inhibits the reabsorption of sodium in the cortical diluting segment. This increases the urinary excretion of sodium and chlorides and, to a lesser extent, of potassium and magnesium. Urine output goes up, and indapamide has an antihypertensive action as a result.