ACE and essential hypertension: The aim of this retrospective chart review study was to examine the cost effectiveness of angiotensin-converting enzyme inhibitors (ACEIs); angiotensin receptor blockers (ARBs); and dihydropyridine calcium channel blockers (CCBs) such as amlodipine, monotherapies in the management of essential hypertension among adult patients (≥18 years) without cancer, cardiovascular disease, and chronic kidney disease in the primary care clinics of a university-affiliated tertiary care hospital.