Chapter 18: Hypertension – Drug Treatment & Clinical Guidelines

Hypertension (HTN), frequently dubbed "the silent killer" due to its often asymptomatic nature, is a widespread chronic condition that significantly elevates the risk for cardiovascular disease (CVD) and chronic kidney disease (CKD). The prevalence of this condition is rising, linked to factors such as increased age, high dietary salt intake, and obesity. HTN is broadly categorized as primary (essential), which accounts for approximately 95% of cases with no identifiable cause but is hypothesized to involve environmental and genetic factors, including the Renin-Angiotensin-Aldosterone System (RAAS) and sympathetic nervous system activity; or secondary, where the cause is identifiable, such as CKD, renovascular issues, sleep apnea, or various medications. Proper diagnosis requires multiple elevated blood pressure (BP) readings taken weeks apart, following strict protocol, or through ambulatory BP monitoring (ABPM) for cases like "white coat hypertension". Treatment is generally a lifelong commitment aimed at managing BP and reducing long-term organ damage, with goals varying based on patient age and comorbidities, as defined by guidelines like the JNC 8 and ACC/AHA 2017 standards. First-line pharmacologic intervention is tailored to the individual, often involving thiazide diuretics, calcium channel blockers (CCBs), ACE inhibitors (ACEIs), or angiotensin II receptor blockers (ARBs). Specific populations have distinct recommendations: for instance, black patients often respond best to CCBs or thiazides, while patients with CKD benefit from an ACEI or ARB to improve renal outcomes. Clinicians must carefully monitor for class-specific adverse effects, such as the chronic dry cough or angioedema (more frequent in African Americans) associated with ACEIs, or the potential for hyperkalemia with RAAS inhibitors and potassium-sparing diuretics. Combination therapy is frequently necessary, though combining multiple RAAS blockers (ACEI/ARB/Renin Inhibitor) is contraindicated due to increased risk of adverse events. Nonpharmacologic management, including weight loss and dietary modification like the DASH diet, is the foundational approach for all patients. Finally, recognizing and appropriately managing hypertensive crisis—distinguished as urgency or emergency based on the presence of acute end-organ damage—is crucial, requiring controlled BP reduction rather than rapid normalization.