Telmisartan ramipril combination therapy reduces strokes and improves cardiac and renal protection in stroke prone spontaneously hypertensive rats

Abstract 

Clinical and animal experimental studies suggest that combination therapy using angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors provides superior blood pressure (BP) lowering and target organ protection than either agent alone. We tested combination therapy with telmisartan and ramipril in lowering BP and protecting against stroke and target-organ damage in salt-fed stroke prone spontaneously hypertensive rats. Twenty-five rats were assigned to each of five groups: control (C), telmisartan (T), ramipril (R), and telmisartan + ramipril at full (TR) and at half-dose (½TR). Full dose telmisartan was 1 mg/kg/day and ramipril .4 mg/kg/day. Rats were fed a stroke prone diet for 8 weeks starting at age 7.5 weeks. Eighty-three percent C and 56% R showed behavioral signs of stroke. There were no strokes in other groups. BP was lower than control in all groups and lowest in TR. Urinary protein excretion, renal damage scores, and left ventricle cardiac collagen areas were lower than controls in all telmisartan treatment groups and lowest in TR. Telmisartan was superior to ramipril in preventing strokes, and telmisartan/ramipril combination therapy provided better BP control and greater cardio-renal protection than telmisartan alone.

Keywords: Combination therapy, angiotensin receptor blocker, angiotensin-converting enzyme inhibitor, spontaneously hypertensive stroke prone rats, target organ damage