Should lisinopril (angiotensin-converting enzyme inhibitor) be stopped in a patient with asymptomatic hyponatremia who is also taking it for blood pressure control?

From the Guidelines

Lisinopril should not be automatically stopped in a patient with asymptomatic hyponatremia who is taking it for blood pressure control. The decision to continue or discontinue lisinopril requires careful evaluation of the severity of hyponatremia, its likely cause, and the patient's overall clinical status.

Key Considerations

• If the hyponatremia is mild (sodium >130 mEq/L) and the patient is truly asymptomatic, it may be reasonable to continue lisinopril while monitoring sodium levels closely 1.
• However, if hyponatremia is moderate to severe (sodium <130 mEq/L) or if there's evidence that lisinopril is contributing to the hyponatremia, the medication should be temporarily discontinued and an alternative antihypertensive considered.
• ACE inhibitors like lisinopril can occasionally cause hyponatremia through multiple mechanisms, including increased antidiuretic hormone (ADH) release, reduced aldosterone levels, and altered renal sodium handling.

Management Approach

• If lisinopril is discontinued, blood pressure should be monitored closely and alternative medications such as calcium channel blockers or beta-blockers may be substituted.
• The underlying cause of hyponatremia should be investigated, including assessment of volume status, other medications, and potential medical conditions that could be contributing factors.
• In patients with heart failure, the use of diuretics, ACE inhibitors, and other medications should be optimized according to current guidelines 1.

From the FDA Drug Label

The recommended starting dose in these patients with hyponatremia (serum sodium < 130 mEq/L) is 2. 5 mg once daily. The FDA drug label does not answer the question.

From the Research

Lisinopril and Hyponatremia

• Lisinopril, an angiotensin-converting enzyme (ACE) inhibitor, has been associated with hyponatremia in some cases 2, 3, 4, 5.
• The mechanism of lisinopril-induced hyponatremia is thought to be related to the inhibition of angiotensin II production, leading to increased levels of angiotensin I, which can stimulate thirst and release of antidiuretic hormone (ADH) from the hypothalamus, resulting in water retention and hyponatremia 5.
• In patients with asymptomatic hyponatremia who are taking lisinopril for blood pressure control, the decision to stop lisinopril should be made on a case-by-case basis, considering the severity of the hyponatremia and the patient's overall clinical condition.

Clinical Considerations

• In some cases, stopping lisinopril has been shown to correct hyponatremia 2, 3, 5.
• However, lisinopril is an effective antihypertensive agent, and stopping it may lead to uncontrolled blood pressure 6.
• Alternative antihypertensive agents may need to be considered in patients who develop hyponatremia while taking lisinopril.

Monitoring and Management

• Patients taking lisinopril should be monitored for signs and symptoms of hyponatremia, including headache, nausea, and tingling sensations 5.
• Serum sodium levels should be checked regularly in patients taking lisinopril, especially in those with a history of hyponatremia or those who are at risk of developing it.
• If hyponatremia is diagnosed, the patient's fluid intake should be restricted, and alternative antihypertensive agents may need to be considered 5.