Can Alendronate (bisphosphonate) cause hyponatremia (low sodium levels)?

From the Guidelines

Alendronate is not typically associated with causing hyponatremia (low sodium levels in the blood). According to the study published in the American Journal of Kidney Diseases 1, there are no reported adverse events specific to chronic kidney disease (CKD) for alendronate, and it does not have any direct effects on sodium balance in the body. The study provides a summary of bisphosphonates and their use in CKD, but it does not mention hyponatremia as a potential side effect of alendronate.

Some key points to consider when evaluating the potential for alendronate to cause hyponatremia include:

• The mechanism of action of alendronate, which involves inhibiting bone resorption, does not directly affect sodium balance in the body.
• The common side effects of alendronate, such as gastrointestinal issues and musculoskeletal pain, do not typically include hyponatremia.
• Other factors, such as other medications (e.g., diuretics, antidepressants, or anticonvulsants), medical conditions affecting fluid balance, or excessive water intake, are more likely to contribute to the development of hyponatremia in patients taking alendronate.

It is essential to note that patients experiencing symptoms of hyponatremia, such as headache, confusion, seizures, or weakness, while on alendronate should seek medical attention, but the medication itself would not be the primary suspect for causing sodium imbalance, as supported by the study 1.

From the Research

Alendronate and Hyponatremia

• There is no direct evidence in the provided studies that alendronate (bisphosphonate) can cause hyponatremia (low sodium levels) 2, 3, 4, 5.
• However, one study mentions a patient with chronic idiopathic hyponatremia due to SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion) who was also being treated with alendronate for osteoporosis 6.
• This study does not suggest that alendronate caused the hyponatremia, but rather that the patient had a pre-existing condition that contributed to the hyponatremia.
• The other studies focus on the efficacy and safety of alendronate in treating osteoporosis, and do not mention hyponatremia as a potential side effect 2, 3, 4, 5.

Related Side Effects

• Alendronate has been associated with upper GI tract adverse events, such as abdominal pain, nausea, and dyspepsia 2, 5.
• There have been reports of nephrotic syndrome and acute renal failure in patients taking alendronate, although these are rare and not directly related to hyponatremia 3, 4.