What medications can cause hyponatremia?

From the Guidelines

Medications that can cause hyponatremia include diuretics, particularly thiazides and loop diuretics, as they increase sodium excretion in urine, as noted in the 2022 European Heart Journal study 1. Hyponatremia can be caused by several medications across different drug classes.

• Diuretics, particularly thiazides (like hydrochlorothiazide and chlorthalidone) and loop diuretics (such as furosemide and bumetanide), are common culprits as they increase sodium excretion in urine.
• Other medications that may cause hyponatremia include certain antibiotics, antidiabetic drugs, non-steroidal anti-inflammatory drugs (NSAIDs), and chemotherapy agents. The mechanism typically involves either increased water retention through ADH effects or increased sodium loss through the kidneys.
• Elderly patients, those with renal impairment, and patients taking multiple medications are at higher risk. Monitoring sodium levels is important when starting these medications, especially in vulnerable populations, as recommended in the 2013 Journal of the American College of Cardiology study 1. It is crucial to be aware of the potential for hyponatremia when prescribing these medications, especially in high-risk populations, and to monitor sodium levels accordingly, as emphasized in the 2022 European Heart Journal study 1.

From the FDA Drug Label

Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including sertraline. Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including Prozac.

Medications that can cause hyponatremia:

• Sertraline (PO) 2
• Fluoxetine (PO) 3

Key points:

• Hyponatremia can occur as a result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH)
• Elderly patients may be at greater risk of developing hyponatremia with SSRIs and SNRIs
• Patients taking diuretics or who are otherwise volume depleted may be at greater risk
• Discontinuation of the medication should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted

From the Research

Medications that Cause Hyponatremia

Medications that can cause hyponatremia include:

• Selective serotonin reuptake inhibitors (SSRIs) 4, 5
• Thiazide diuretics 4, 5, 6, 7
• Antipsychotic drugs 8

Mechanisms of Hyponatremia

The mechanisms by which these medications cause hyponatremia include:

• Impairment of urinary dilution 5, 7
• Renal loss of sodium and potassium 5
• Stimulation of antidiuretic hormone (ADH) release 5, 7
• Syndrome of inappropriate ADH release (SIADH) 5, 8
• Increased water intake (dipsogenic effect) 5

Patient Characteristics and Risk Factors

Patients at increased risk of hyponatremia include:

• Older adults 4, 5, 7
• Elderly women 5
• Patients with a history of polydipsia 8
• Patients with schizophrenia 8
• Frail elderly patients with high water intake or those who depend on the excretion of maximally dilute urine to maintain fluid balance 7