Adding Third-Line Antihypertensive Therapy to ACE Inhibitor and Beta Blocker
Add a dihydropyridine calcium channel blocker (amlodipine 2.5-5 mg daily) as the preferred third agent for elderly patients already on lisinopril and carvedilol. 1
Primary Recommendation: Calcium Channel Blocker
The most appropriate next step is adding amlodipine, starting at a low dose of 2.5 mg daily in elderly patients, with gradual titration to minimize vasodilatory side effects. 1 This recommendation follows the guideline-directed approach of combining a RAS blocker (lisinopril) with a dihydropyridine calcium channel blocker as preferred combination therapy. 1
Key advantages of amlodipine in elderly patients:
- Does not cause bradycardia, which is particularly important since the patient is already on carvedilol (a beta blocker). 1
- Well-tolerated in elderly populations with proven efficacy. 1, 2
- More effective at lowering systolic blood pressure in elderly patients compared to beta blockers or ACE inhibitors alone. 3
- Can be prescribed safely in the presence of multiple comorbid conditions common in elderly patients. 2
Dosing algorithm:
- Start amlodipine 2.5 mg daily and assess response in 2-4 weeks. 1
- If blood pressure remains uncontrolled, increase to 5 mg daily. 1
- Elderly patients have 40-60% higher drug exposure due to decreased clearance, making lower initial dosing essential. 4
Alternative Option: Thiazide-Like Diuretic
If amlodipine is not tolerated or contraindicated, add a thiazide-like diuretic as the alternative third-line agent. 1, 5
Preferred thiazide-like diuretics:
- Chlorthalidone 12.5 mg daily (can increase to 25 mg). 1, 5
- Indapamide 1.25 mg daily (can increase to 2.5 mg). 1, 5
Important considerations with diuretics in elderly patients:
- Start with lower doses (chlorthalidone 12.5 mg or indapamide 1.25 mg) to minimize adverse effects. 5
- Monitor electrolytes (particularly potassium) and renal function 1-2 weeks after initiation. 1, 5
- Check for orthostatic hypotension by measuring blood pressure in both sitting and standing positions. 1, 5
- Watch for hypokalemia, hyperuricemia, and glucose intolerance. 5
Thiazide-like diuretics are more effective than traditional thiazides due to longer duration of action and superior cardiovascular outcomes. 5 They are also more effective at lowering systolic blood pressure in elderly patients compared to beta blockers. 3
Blood Pressure Targets and Monitoring
Target blood pressure for elderly patients:
- Aim for <140/90 mmHg if tolerated as the minimum goal. 1, 6
- Consider <130/80 mmHg if well-tolerated. 5, 6
Monitoring schedule:
- Recheck blood pressure within 4 weeks of medication adjustment. 1, 5, 6
- Target blood pressure control should be achieved within 3 months. 1, 5, 6
- Always check for orthostatic hypotension in elderly patients. 1, 5
Common Pitfalls to Avoid
Do not simply increase beta blocker dose: Beta blockers are relatively ineffective at lowering systolic blood pressure in elderly patients and have more side effects including central nervous system effects. 7, 3
Avoid starting with high doses: Elderly patients require lower initial doses due to altered pharmacokinetics and increased sensitivity to medications. 1, 4
Do not use loop diuretics as first-line: Torsemide and other loop diuretics do not fulfill the role of first-line antihypertensive therapy. 1
If Blood Pressure Remains Uncontrolled
If blood pressure remains uncontrolled after optimizing the three-drug regimen (ACE inhibitor + beta blocker + calcium channel blocker or diuretic), consider adding spironolactone 25 mg for resistant hypertension. 6 Alternatively, refer to a hypertension specialist if target blood pressure is not achieved after implementing these adjustments. 6
Maintain lifelong treatment: Continue blood pressure-lowering treatment even beyond age 85 if well tolerated, as discontinuation increases cardiovascular risk. 1