What complications are patients at increased risk of when taking ACE inhibitors compared to ARBs?

Patients taking ACE inhibitors are at increased risk for hypotension, hyperkalemia, and renal dysfunction due to the specific mechanisms of action and side effects associated with these medications.

ACE inhibitors work by inhibiting the angiotensin-converting enzyme, which leads to decreased production of angiotensin II. This reduction results in vasodilation, or widening of the blood vessels, which can lower blood pressure and potentially lead to hypotension, especially after the initial doses. This effect is particularly relevant in patients who may already be on diuretics or are volume-depleted, making blood pressure drops more pronounced.

Moreover, ACE inhibitors can increase potassium levels in the blood, leading to hyperkalemia. This occurs because the inhibition of angiotensin II reduces the secretion of aldosterone, a hormone that promotes the excretion of potassium. Patients with underlying kidney issues or those on potassium-sparing diuretics are especially prone to this complication.

Renal dysfunction is another complication that can arise, particularly in individuals with pre-existing renal impairment or those who are volume-depleted. The alteration in renal blood flow caused by the vasodilation of the efferent arterioles can lead to elevated serum creatinine and further deterioration of renal function in susceptible individuals.