In a 74‑year‑old man with coronary artery disease, erectile dysfunction, right‑ventricular conduction delay, and persistent blood pressure around 160/90 mm Hg despite taking amlodipine 10 mg, losartan 160 mg, hydrochlorothiazide 25 mg, and eplerenone 25 mg, how can his antihypertensive regimen be optimized to achieve a target of <130/<80 mm Hg?

Optimizing Antihypertensive Therapy in Resistant Hypertension with Coronary Artery Disease

Increase eplerenone to 50 mg daily as the next step, as this patient is already on a maximally-dosed four-drug regimen and requires intensification with the mineralocorticoid receptor antagonist (MRA) he is already taking at a suboptimal dose.

Current Regimen Assessment

This patient is on a four-drug regimen but has not achieved adequate blood pressure control. His current medications include:

• Amlodipine 10 mg (maximal dose calcium channel blocker) 1
• Losartan 160 mg (maximal dose ARB, though standard maximum is typically 100 mg) 2
• Hydrochlorothiazide 25 mg (maximal dose thiazide diuretic)
• Eplerenone 25 mg (submaximal dose MRA) 3

The target blood pressure for this patient with coronary artery disease should be <130/80 mm Hg 4. The 2017 ACC/AHA guidelines specifically recommend this target for patients with stable ischemic heart disease and hypertension 4.

Recommended Next Step: Titrate Eplerenone

The most appropriate next step is to increase eplerenone from 25 mg to 50 mg daily 3. According to the FDA label, eplerenone should be titrated to a maximum of 50 mg once daily within 4 weeks as tolerated, with dose adjustments based on potassium levels 3. This patient is currently on only half the target dose of his MRA.

Rationale for MRA Intensification

The 2020 International Society of Hypertension guidelines clearly position spironolactone (or eplerenone if not tolerated) as the fourth-line agent in resistant hypertension after maximizing an ARB/ACE inhibitor, calcium channel blocker, and thiazide diuretic 4. The 2018 AHA Scientific Statement on Resistant Hypertension specifically recommends adding or optimizing an MRA as Step 3 in the treatment algorithm 4.

Before titrating eplerenone, measure serum potassium and creatinine clearance 3. Eplerenone is contraindicated if serum potassium exceeds 5.5 mEq/L or creatinine clearance is ≤30 mL/min 3. Given his age and coronary disease, monitor potassium levels periodically after dose adjustment 3.

Alternative Considerations if Eplerenone Titration Fails

If blood pressure remains uncontrolled after maximizing eplerenone to 50 mg daily, the next steps according to the AHA Resistant Hypertension algorithm would be 4:

Step 4: Add Beta-Blocker

Add a beta-blocker (metoprolol succinate or bisoprolol) if heart rate is ≥70 beats/min 4. This is particularly appropriate given his coronary artery disease history 4. The 2017 ACC/AHA guidelines recommend beta-blockers as part of guideline-directed medical therapy (GDMT) for patients with stable ischemic heart disease 4.

• Beta-blockers are specifically indicated for patients with prior MI or stable angina 4
• If beta-blockers are contraindicated, consider a central alpha-agonist (clonidine patch weekly) 4
• Alternatively, once-daily diltiazem could be considered if beta-blockers are not tolerated, though avoid if bradycardia is present 4

Step 5: Add Vasodilator

If still uncontrolled, add hydralazine 25 mg three times daily and titrate upward 4.

Diuretic Optimization Consideration

Consider switching hydrochlorothiazide to chlorthalidone 12.5-25 mg daily 4. The AHA Resistant Hypertension guidelines specifically recommend substituting a thiazide-like diuretic (chlorthalidone or indapamide) for standard thiazides as Step 2 in resistant hypertension 4. Chlorthalidone has superior 24-hour blood pressure control and longer duration of action compared to hydrochlorothiazide, though this substitution is listed as Step 2 in the algorithm and the patient is already beyond that stage 4.

Addressing Erectile Dysfunction Concerns

The patient's erectile dysfunction should not limit antihypertensive intensification, but drug selection matters 5, 6.

• Losartan (ARB) has neutral to positive effects on erectile function and may actually improve ED compared to other antihypertensive classes 7, 8
• Amlodipine (calcium channel blocker) appears neutral regarding erectile function 9, 8
• Hydrochlorothiazide and other diuretics are associated with increased ED risk 6, 10, 8, providing additional rationale to consider switching to chlorthalidone (though this may not improve ED)
• Eplerenone (MRA) has less favorable effects on erectile function compared to ARBs 6, but the cardiovascular benefits outweigh this concern in resistant hypertension
• Beta-blockers, particularly non-selective ones, are associated with ED 6, 10, 8, though nebivolol has a better profile 8. If a beta-blocker is added, consider nebivolol or a cardioselective agent like bisoprolol or metoprolol succinate

Erectile dysfunction itself is a marker of endothelial dysfunction and cardiovascular disease 5, 11, and optimizing blood pressure control may actually improve erectile function by reducing cardiovascular risk 5.

Monitoring and Follow-Up

• Measure serum potassium before increasing eplerenone and 1-2 weeks after dose adjustment 3
• Reassess blood pressure within 2-4 weeks after medication adjustment 4
• Confirm home blood pressure readings to exclude white-coat hypertension 4
• Assess medication adherence, as pseudo-resistance due to non-adherence is common 4
• Screen for secondary causes of hypertension if blood pressure remains uncontrolled despite four or more medications at maximal doses 4

Common Pitfalls to Avoid

• Do not add a beta-blocker before maximizing the MRA dose 4
• Avoid combining non-dihydropyridine calcium channel blockers (diltiazem/verapamil) with beta-blockers due to risk of bradycardia and heart block 4
• Do not use potassium supplements or potassium-sparing diuretics in combination with eplerenone without close monitoring, as hyperkalemia risk is significantly increased 3
• Avoid excessive diastolic blood pressure lowering (<60 mm Hg) in patients with coronary disease, as this may worsen myocardial ischemia 4