How to manage uncontrolled hypertension in a patient on losartan/HCTZ (hydrochlorothiazide) and metoprolol succinate?

Management of Uncontrolled Hypertension with BP 130/96 on Current Therapy

For a patient with uncontrolled hypertension (BP 130/96) despite being on losartan/HCTZ 50/12.5 mg and metoprolol succinate 50 mg, the recommended approach is to switch from hydrochlorothiazide to chlorthalidone and add a calcium channel blocker to create a triple therapy regimen.

Current Medication Assessment

The patient is currently on:

• Losartan/HCTZ 50/12.5 mg (ARB + thiazide diuretic combination)
• Metoprolol succinate 50 mg (beta-blocker)

This regimen is insufficient as evidenced by the blood pressure of 130/96 mmHg, which meets criteria for uncontrolled hypertension according to the 2017 ACC/AHA guidelines 1.

Recommended Medication Adjustments

Step 1: Optimize Diuretic Therapy

• Replace hydrochlorothiazide with chlorthalidone (12.5-25 mg daily)
  • Chlorthalidone has been shown to be more effective than HCTZ with better 24-hour blood pressure control and superior outcomes 1, 2
  • The 2017 ACC/AHA guidelines specifically recommend chlorthalidone or indapamide over HCTZ for resistant hypertension 1

Step 2: Add a Third Agent

• Add a dihydropyridine calcium channel blocker (e.g., amlodipine 5-10 mg daily)
  • Triple therapy with an ARB, diuretic, and calcium channel blocker is recommended for uncontrolled hypertension 2
  • This combination targets three different mechanisms of blood pressure control

Step 3: Consider Dose Adjustments

• If needed, increase losartan to 100 mg daily
  • The FDA label indicates that losartan may be titrated up to 100 mg for better blood pressure control 3
• Maintain or adjust metoprolol succinate based on heart rate and tolerance

Rationale for Recommendations

1. Superiority of Chlorthalidone: The ACC/AHA guideline on resistant hypertension specifically states that "chlorthalidone has been compared to HCTZ directly and lowers BP more effectively, particularly at night, and has a much longer therapeutic half-life" 1.

2. Triple Therapy Approach: For patients with uncontrolled hypertension on two medications, adding a third agent from a different class is recommended by current guidelines 1, 2.

3. Combination Selection: The combination of RAS blocker (ARB), calcium channel blocker, and diuretic has shown superior efficacy compared to other combinations for resistant hypertension 2.

Monitoring and Follow-up

• Schedule follow-up within 2-4 weeks after medication changes
• Monitor:
  • Blood pressure (target <130/80 mmHg)
  • Serum potassium and renal function, particularly with the ARB and diuretic combination
  • Symptoms of orthostasis or other adverse effects

Common Pitfalls to Avoid

1. Inadequate Diuretic: Continuing with HCTZ when chlorthalidone has demonstrated better outcomes

2. Dual RAS Blockade: Adding an ACE inhibitor to the current ARB regimen should be avoided due to increased risk of hyperkalemia and renal dysfunction without significant benefit 2

3. Delayed Intensification: Waiting too long to adjust therapy when blood pressure remains uncontrolled

4. Overlooking Adherence: Ensure the patient is taking medications as prescribed before adding new agents

If blood pressure remains elevated despite these adjustments, consider referral to a hypertension specialist, as this would meet criteria for resistant hypertension (BP above goal despite optimal doses of three different classes of antihypertensive medications including a diuretic) 1.