A 74-year-old woman returns for a 6-week follow-up after her antihypertensive was escalated to amlodipine (Norvasc) 10 mg daily. Her BP is now well controlled at 128/78 mm Hg, but she reports new bilateral pitting ankle edema that worsens throughout the day. She denies dyspnea, orthopnea, paroxysmal nocturnal dyspnea, or weight gain beyond 1 lb. Lung auscultation is clear; JVP is not elevated. BNP is within normal limits. What is the MOST likely explanation for her edema?

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Accepted Answer

✅ D. Dose-dependent peripheral edema from amlodipine (a dihydropyridine CCB adverse effect)
Dihydropyridine CCB-induced edema is a classic, dose-dependent adverse effect caused by preferential arteriolar (pre-capillary) vasodilation without corresponding venous dilation, which raises capillary hydrostatic pressure and drives fluid into the interstitium. It typically presents as bilateral, symmetric, gravity-dependent pitting edema WITHOUT signs of fluid overload (no JVD, no rales, normal BNP, no weight gain from systemic volume). Incidence increases with dose — approximately 2 to 3% at 2.5 mg, up to 25% or more at 10 mg. Management is dose reduction, switching to a non-DHP or another antihypertensive class, or adding an ACE/ARB which offsets the hydrostatic imbalance.

❌ A. New-onset congestive heart failure with volume overload
Volume-overload HF would typically present with elevated JVP, pulmonary rales, dyspnea or orthopnea, and elevated BNP. This patient has none of those features, and the timing with amlodipine uptitration makes a drug effect far more likely.

❌ B. Deep vein thrombosis
DVT is typically unilateral, associated with calf pain, warmth, and a positive Homans sign. Bilateral symmetric edema without pain argues strongly against DVT.

❌ C. Chronic venous insufficiency (new onset)
CVI can cause bilateral lower-extremity edema but usually develops gradually over years with skin changes (stasis dermatitis, hemosiderin deposition, varicosities). New, sudden-onset bilateral pitting edema 6 weeks after starting a known edema-causing drug points squarely to the medication.

:::pearl
DHP CCB edema is NOT relieved by diuretics (the fluid is local, not systemic) and giving a loop diuretic for this presentation causes volume depletion and AKI without fixing the edema. Correct actions: reduce the dose, switch to a non-DHP like diltiazem (if no HFrEF), or add an ACE/ARB which neutralizes the capillary hydrostatic imbalance.
:::

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