Next Step: Add a Thiazide-Like Diuretic
The next step is to add a thiazide-like diuretic (such as chlorthalidone or indapamide) to this patient's regimen. 1
Rationale Based on Treatment Algorithm
This 76-year-old patient is currently on:
- Maximum-dose ACE inhibitor (lisinopril, max 80 mg) 2
- Maximum-dose calcium channel blocker (amlodipine, max 10 mg) 3
- Beta-blocker (metoprolol)
With a systolic BP of 160 mmHg, the patient remains significantly above target despite triple therapy. According to the 2020 International Society of Hypertension guidelines, the stepwise approach for non-Black patients dictates that after maximizing ACE inhibitor/ARB and adding a dihydropyridine calcium channel blocker at full dose, the fourth step is to add a thiazide or thiazide-like diuretic. 1
Why Thiazide-Like Diuretic is Preferred
Guideline-directed sequence: The ISH 2020 algorithm explicitly places thiazide/thiazide-like diuretics as step 4 in the treatment ladder for non-Black patients before considering spironolactone or other agents 1
CKD considerations: While this patient has CKD, thiazide-like diuretics (particularly chlorthalidone and indapamide) remain effective even with moderate renal impairment, unlike traditional thiazides which lose efficacy when eGFR falls below 30 mL/min 1
Evidence in similar populations: The ALLHAT trial demonstrated that chlorthalidone was at least as effective as lisinopril or amlodipine in older hypertensive patients with CKD, with no increased risk of ESRD during long-term follow-up 4
Specific Recommendations
Start with a low dose of a thiazide-like diuretic:
- Chlorthalidone 12.5 mg once daily, or
- Indapamide 1.25 mg once daily 1
Critical Monitoring Parameters
After adding the diuretic, monitor within 2-4 weeks for: 1
- Electrolytes: Particularly potassium (risk of hypokalemia with diuretic, but patient is on ACE inhibitor which may counterbalance this) and sodium
- Renal function: Serum creatinine (acceptable if rises <30% from baseline) 1
- Blood pressure response: Target is <140/90 mmHg for this elderly patient, though <130/80 mmHg is ideal if tolerated without adverse effects 1
- Volume status: Assess for orthostatic hypotension given age and multiple BP medications
When to Consider Spironolactone Instead
If the patient has resistant hypertension after adding the thiazide-like diuretic (step 5), or if there are contraindications to thiazides, then spironolactone 25 mg daily would be the next agent. 1 However, spironolactone should be used cautiously in CKD due to hyperkalemia risk, particularly when combined with an ACE inhibitor. 1
Important Caveats
- Verify medication adherence before adding another agent, as non-adherence is a common cause of apparent treatment resistance 1
- Confirm home BP readings if available, as office readings may overestimate true hypertension (white coat effect) 1
- Consider frailty status: At age 76, if the patient is frail, a more conservative BP target of 140/90 mmHg may be more appropriate to avoid adverse effects from overtreatment 1
- Assess for secondary causes of hypertension if BP remains uncontrolled after optimizing four-drug therapy 1