ACE and hypertensive disorder: Currently, the first-line drugs used in the treatment of essential hypertension include thiazide diuretics, long-acting calcium channel blockers, angiotensin-converting enzyme inhibitors (ACEI), and angiotensin II receptor blockers (ARBs).[16] However, long-term use of these drugs can bring certain side effects to patients, such as headache, facial flush, and other symptoms.