Which is a primary characteristic of ACE inhibitors?

ACE inhibitors (Angiotensin-Converting Enzyme inhibitors) are primarily characterized by their ability to lead to decreased blood pressure. They work by inhibiting the enzyme that converts angiotensin I to angiotensin II, a potent vasoconstrictor. By reducing the levels of angiotensin II, ACE inhibitors promote vasodilation, which in turn lowers blood pressure. This mechanism makes them effective in the treatment of hypertension, as well as in heart failure and other cardiovascular conditions.

While it is true that ACE inhibitors can also have effects on potassium levels, the primary characteristic that distinguishes them is their role in lowering blood pressure. Other options presented, such as causing vasoconstriction or promoting fluid retention, do not align with the mechanism of action of ACE inhibitors, which are designed to reduce blood pressure and improve hemodynamics. Thus, the recognition of ACE inhibitors as agents that primarily decrease blood pressure is crucial in understanding their therapeutic applications.