Should I add another antihypertensive medication to a 65-year-old female patient with uncontrolled Hypertension (HTN) and rising serum creatinine levels on telmisartan (Angiotensin II receptor antagonist) and amlodipine (Calcium channel blocker)?

Management of Hypertension with Rising Creatinine in an Elderly Patient

A thiazide-like diuretic should be added as the third antihypertensive agent for this 65-year-old female patient with uncontrolled hypertension and rising serum creatinine who is currently on telmisartan and amlodipine. 1

Patient Assessment

• 65-year-old female with hypertension
• Current medications: telmisartan 40 mg and amlodipine 5 mg
• BP: 150/70 mmHg (uncontrolled)
• Serum creatinine: increased from 0.8 to 1.6 mg/dL over 4 months
• Weight: 45 kg
• Ultrasound: no evidence of CKD

Rationale for Adding a Thiazide-like Diuretic

Step-wise Approach Based on Guidelines

According to the 2020 International Society of Hypertension guidelines, the recommended step-wise approach for non-black patients with uncontrolled hypertension on an ARB (telmisartan) and DHP-CCB (amlodipine) is to add a thiazide/thiazide-like diuretic as the third agent 1.

The treatment algorithm for this patient should follow:

1. ARB (telmisartan) - already on this
2. DHP-CCB (amlodipine) - already on this
3. Add thiazide/thiazide-like diuretic - recommended next step

Considerations for Rising Creatinine

The doubling of serum creatinine (0.8 to 1.6 mg/dL) requires careful consideration:

1. The rise in creatinine may be partially related to the ARB (telmisartan), which can cause a functional increase in creatinine by reducing intraglomerular pressure 2.

2. Despite the rising creatinine, thiazide-like diuretics remain appropriate as:

   • They are specifically recommended for patients with hypertension and evidence of organ damage 1
   • Low-dose thiazide-like diuretics have minimal adverse metabolic effects 3

Specific Diuretic Recommendation

Chlorthalidone at a low dose (12.5 mg) is preferred over hydrochlorothiazide 4 because:

• Superior 24-hour blood pressure control
• Greater efficacy at lower doses
• Less metabolic disturbance at equivalent antihypertensive doses

Monitoring Plan

After adding the thiazide-like diuretic:

1. Monitor blood pressure weekly for the first month
2. Check serum electrolytes and renal function within 1-2 weeks
3. Target BP should be <140/90 mmHg (considering age and rising creatinine)
4. Reassess BP control within 3 months 1

Important Precautions

• Start at a low dose (12.5 mg chlorthalidone) given the patient's low weight (45 kg) and age
• Monitor for electrolyte disturbances, particularly hypokalemia and hyponatremia
• If creatinine continues to rise significantly after adding the diuretic, consider:
  • Reducing the ARB dose
  • Evaluating for renal artery stenosis
  • Nephrology consultation

Alternative Options

If thiazide-like diuretics are not tolerated or contraindicated:

1. Spironolactone (25 mg) would be the next best option 1, 4
2. If not suitable, consider doxazosin, eplerenone, or a beta-blocker 1

The combination of telmisartan and amlodipine has proven efficacy 5, 6, 7, but the addition of a third agent is necessary when BP remains uncontrolled, as in this case.