Olmesartan Medoxomil (20mg) + Amlodipine (5mg) + Hydrochlorothiazide (12.5mg) (Medical Monograph)

Overview

A fixed-dose combination (FDC) antihypertensive medication containing an angiotensin II receptor blocker (ARB), a dihydropyridine calcium channel blocker (CCB), and a thiazide diuretic. This triple-drug combination is indicated for the treatment of essential hypertension in patients whose blood pressure is not adequately controlled on any two of the following classes: ARBs, CCBs, and thiazide diuretics. It provides synergistic action by targeting multiple pathways of blood pressure regulation, offering enhanced efficacy and improved compliance.

The combination exerts a synergistic antihypertensive effect through three distinct mechanisms: 1) Olmesartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively antagonizing the AT1 receptor. 2) Amlodipine inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle, causing peripheral arterial vasodilation and reduced peripheral vascular resistance. 3) Hydrochlorothiazide inhibits sodium reabsorption in the distal convoluted tubule of the nephron, increasing excretion of sodium, chloride, and water, thereby reducing plasma volume.