A 52-year-old man with hypertension on amlodipine monotherapy presents with a BP of 158/96 mmHg at follow-up. He reports ankle edema and gum hyperplasia. His serum creatinine is 0.9 mg/dL and eGFR is 92 mL/min/1.73m². What is the most appropriate next step in management?

Explanation

## Clinical Scenario Analysis The patient has uncontrolled hypertension (BP 158/96 mmHg) despite amlodipine monotherapy. He is experiencing dose-dependent adverse effects (ankle edema and gum hyperplasia), which are classic side effects of dihydropyridine calcium channel blockers (CCBs). ## Why Switching or Increasing the CCB Is Suboptimal **Key Point:** Increasing amlodipine dose would worsen peripheral edema and gum hyperplasia, as these are dose-dependent effects of dihydropyridines. **High-Yield:** Switching to diltiazem (a non-dihydropyridine CCB) may reduce edema, but diltiazem alone is insufficient for BP control in this patient. Adding an ACE inhibitor to diltiazem is reasonable, but the most guideline-concordant approach is to add a complementary agent to the existing amlodipine. ## Rationale for Thiazide Diuretic Addition **Clinical Pearl:** Thiazide diuretics (hydrochlorothiazide 12.5–25 mg daily) are the preferred second-line agent to add to a CCB because: 1. They have synergistic BP-lowering effects with CCBs 2. They do not worsen the adverse effects of amlodipine (edema, gum hyperplasia) 3. They provide additional cardiovascular and renal protection 4. This combination is recommended by major hypertension guidelines (ACC/AHA, ESC/ESH) for resistant hypertension **Mnemonic:** **ACE-ARB-CCB-Diuretic** — the standard stepwise approach. When CCB monotherapy fails, add a diuretic or ACE-I/ARB, not another CCB or beta-blocker. ## Why Beta-Blocker Is Less Ideal Beta-blockers are not first-line agents for uncomplicated hypertension in this age group (no indication like CAD, post-MI, or heart failure). They also lack synergy with CCBs for BP reduction and may cause fatigue. ## Summary Table | Agent Class | Rationale | Evidence | | --- | --- | --- | | Thiazide diuretic | Synergistic with CCB, no worsening of edema/gum hyperplasia | ACC/AHA, ESC/ESH guidelines | | ACE-I/ARB | Alternative; good renal protection but less synergistic | Second-line option | | Beta-blocker | Not first-line for uncomplicated HTN; no synergy | Not recommended as add-on to CCB | | Increased CCB dose | Worsens dose-dependent adverse effects | Contraindicated |