What is a good choice of antihypertensive medication for a patient with stage 2 hypertension (blood pressure 139/113 mmHg) already taking lisinopril (angiotensin-converting enzyme inhibitor) 10 mg?

Management of Stage 2 Hypertension with Blood Pressure 139/113 mmHg in a Patient Already Taking Lisinopril 10 mg

For a patient with stage 2 hypertension (BP 139/113 mmHg) already taking lisinopril 10 mg, adding a long-acting dihydropyridine calcium channel blocker (CCB) such as amlodipine is the best next step in management.

Rationale for Adding a Calcium Channel Blocker

The current blood pressure reading of 139/113 mmHg indicates inadequate control on lisinopril 10 mg monotherapy. According to the most recent guidelines:

• The 2024 ESC guidelines recommend combination therapy for most patients with confirmed hypertension, with preferred combinations being a RAS blocker (ACE inhibitor or ARB) with either a dihydropyridine CCB or diuretic 1.
• When blood pressure is not controlled on monotherapy, adding a second agent from a different class is recommended rather than simply increasing the dose of the first medication 1.
• The patient is already on an ACE inhibitor (lisinopril), making a dihydropyridine CCB the logical next addition.

Medication Selection Algorithm

1. First step (current): ACE inhibitor (lisinopril 10 mg)
2. Second step (recommended): Add long-acting dihydropyridine CCB (amlodipine 5 mg)
3. Third step (if needed later): Add thiazide/thiazide-like diuretic if BP remains uncontrolled

Benefits of Adding a CCB to Lisinopril

• The combination of an ACE inhibitor and CCB has shown superior efficacy compared to monotherapy with either agent 2, 3.
• In a randomized crossover study, the combination of lisinopril and amlodipine demonstrated significant additional blood pressure-lowering effects compared to either drug alone 3.
• This combination provides complementary mechanisms of action:
  • Lisinopril blocks the renin-angiotensin system
  • Amlodipine causes peripheral vasodilation through calcium channel blockade

Dosing Considerations

• Start with amlodipine 5 mg once daily
• The combination of low-dose amlodipine (2.5 mg) with lisinopril (5 mg) has been shown to produce significant blood pressure lowering in a higher percentage of patients than individual low-dose therapy 2.
• If blood pressure remains uncontrolled after 2-4 weeks, consider:
  1. Increasing amlodipine to 10 mg
  2. Increasing lisinopril to 20-40 mg
  3. Adding a thiazide diuretic as a third agent

Monitoring Recommendations

• Recheck blood pressure in 2-4 weeks after adding amlodipine
• Monitor for potential side effects:
  • Peripheral edema (from CCB)
  • Dizziness from enhanced blood pressure lowering
  • Electrolytes and renal function

Alternative Approaches

If a CCB is contraindicated or not tolerated, a thiazide or thiazide-like diuretic would be an appropriate alternative second agent 1.

Special Considerations

• The patient's current diastolic BP of 113 mmHg indicates urgent need for better control to reduce cardiovascular risk
• Single-pill combinations of ACE inhibitor and CCB should be considered once doses are stabilized to improve adherence 1, 4
• If BP remains uncontrolled on triple therapy (ACE inhibitor + CCB + diuretic), adding spironolactone should be considered 1

Common Pitfalls to Avoid

• Avoid simply increasing the lisinopril dose without adding a second agent, as combination therapy is more effective than high-dose monotherapy
• Avoid non-dihydropyridine CCBs (verapamil, diltiazem) if the patient has heart failure or conduction abnormalities
• Avoid combining two RAS blockers (such as adding an ARB to the ACE inhibitor), as this is not recommended due to increased adverse effects without additional benefit 1