What are the implications of a 73-year-old female with impaired renal function, taking Hydrochlorothiazide (HCTZ) for hypertension?

From the Guidelines

I strongly recommend considering alternative blood pressure medications for a 73-year-old female with impaired renal function, as Hydrochlorothiazide (HCTZ) may not be the optimal choice due to its potential to worsen kidney function or cause electrolyte imbalances in patients with reduced GFR, as suggested by the 2018 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1.

Implications of HCTZ in Impaired Renal Function

The use of HCTZ in patients with impaired renal function can lead to several complications, including:

• Reduced efficacy in controlling blood pressure
• Increased risk of electrolyte imbalances, such as hypokalemia and hyponatremia
• Potential worsening of kidney function, particularly in patients with moderate to severe chronic kidney disease (CKD)

Alternative Medications

Alternative medications, such as ACE inhibitors (e.g., lisinopril) or ARBs (e.g., losartan), may be more suitable for managing hypertension in patients with impaired renal function, as they can help protect kidney function while controlling blood pressure, as recommended by the 2018 guideline 1 and further supported by the 2022 European Society of Cardiology working group on cardiovascular pharmacotherapy review 1.

Monitoring and Management

Regular monitoring of kidney function, electrolytes (particularly potassium), and blood pressure is essential, regardless of which medication is used. Patients should also maintain adequate hydration and follow any sodium restrictions recommended by their doctor to support both blood pressure control and kidney health.

Key Considerations

When considering alternative medications, it is essential to:

• Start with low doses and adjust based on the patient's response
• Monitor for potential adverse effects, such as hyperkalemia or hypotension
• Consider the patient's overall health status, including any comorbidities or concomitant medications, as highlighted in the 2022 review 1

From the FDA Drug Label

A greater blood pressure reduction and an increase in side effects may be observed in the elderly (i.e., >65 years) with hydrochlorothiazide. Starting treatment with the lowest available dose of hydrochlorothiazide (12.5 mg) is therefore recommended. If further titration is required, 12.5 mg increments should be utilized.

The implications of a 73-year-old female with impaired renal function taking Hydrochlorothiazide (HCTZ) for hypertension are that she may experience increased side effects due to her age.

• The patient should be started on the lowest available dose of 12.5 mg.
• Close monitoring is necessary to determine if the desired effect of the diuretic is obtained, especially considering her impaired renal function.
• However, the label does not directly address impaired renal function, so caution should be exercised when using HCTZ in this patient population 2.

From the Research

Implications of Hydrochlorothiazide (HCTZ) in a 73-year-old Female with Impaired Renal Function

• The use of thiazide diuretics, such as HCTZ, in patients with chronic kidney disease (CKD) is often viewed as ineffective in reducing blood pressure, especially when the estimated glomerular filtration rate (eGFR) is below 50 ml/min/1.73m(2) 3.
• However, recent clinical trial data suggest that thiazide and thiazide-like diuretics possess important and clinically significant antihypertension properties, even in patients with eGFR in the 15-45 ml/min range 3.
• The combination of an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB) with a thiazide diuretic, such as HCTZ, may be an effective strategy to reduce blood pressure and preserve renal function in patients with CKD 4, 5.
• A study found that treatment with zofenopril, an ACE inhibitor, alone or in combination with HCTZ, resulted in a reduction in albumin creatinine ratio and no changes in glomerular filtration rate, suggesting that this combination may confer some kidney protection due to ACE inhibition properties 6.

Renal Protection and Antihypertensive Therapy

• International guidelines recommend lowering blood pressure to 140/90 mm Hg or less in patients with uncomplicated hypertension, and to 130/80 mm Hg or less for patients with diabetic or chronic renal disease 4, 5.
• ACE inhibitors and ARBs have beneficial effects on proteinuria and declining renal function that appear to be mediated by factors additional to their effects on blood pressure 4, 5.
• The use of high doses of ACE inhibitors and ARBs, and their up-titration in patients with chronic heart failure and CKD, may be appropriate provided that the patient is adequately monitored 7.

Considerations for Patients with Impaired Renal Function

• Patients with CKD should be closely monitored for changes in renal function, worsening heart failure, and hyperkalemia when treated with antihypertensive medications, including thiazide diuretics like HCTZ 7.
• The choice of antihypertensive therapy should be individualized based on the patient's specific clinical characteristics, including the stage of CKD, presence of proteinuria, and other comorbidities 4, 5.