Which of the following classes of anti-hypertensives can be used as monotherapy?

ACE inhibitors are commonly used as monotherapy in the management of hypertension due to their effectiveness in lowering blood pressure and their favorable profile in patients with various comorbid conditions, such as heart failure and diabetes. They work by inhibiting the angiotensin-converting enzyme, which leads to decreased production of angiotensin II, a potent vasoconstrictor. This results in vasodilation, reduced blood volume, and ultimately lowers blood pressure.

While other classes of anti-hypertensives, such as beta-blockers, calcium channel blockers, and alpha agonists, can also be utilized for treating hypertension, they are often used in conjunction with other medications to achieve optimal blood pressure control. Beta-blockers, for instance, may be more effective when used alongside other agents, especially in certain patient populations. Calcium channel blockers can also be very effective, but they sometimes result in peripheral edema, requiring the addition of diuretics for better management. Alpha agonists are less frequently used as first-line agents and are usually reserved for specific circumstances.

Thus, ACE inhibitors stand out as a class that is widely accepted for use as monotherapy, making them appropriate for many patients needing treatment for high blood pressure.