From the FDA Drug Label
Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including duloxetine delayed-release capsules. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH)
- Duloxetine can cause hyponatremia, which is a reduction in sodium levels.
- The FDA drug label for duloxetine warns that hyponatremia may occur as a result of treatment with duloxetine, and that it can be reversible when the medication is discontinued 1.
- Therefore, duloxetine can reduce sodium levels, but this is an adverse effect rather than a therapeutic one.
From the Research
Duloxetine can potentially reduce sodium levels in the body, causing a condition called hyponatremia, as evidenced by the most recent and highest quality study available 2. This is an uncommon but serious side effect of Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) like duloxetine. The risk is higher in elderly patients, those taking diuretics, and patients with existing low sodium levels or conditions like SIADH (Syndrome of Inappropriate Antidiuretic Hormone secretion). Some key points to consider:
- Duloxetine affects the regulation of antidiuretic hormone, which controls water retention and sodium concentration in the blood 3, 4.
- Symptoms of hyponatremia include headache, confusion, weakness, seizures, and in severe cases, coma 5, 6.
- Patients taking duloxetine should be aware of these potential symptoms and seek medical attention if they occur.
- Healthcare providers typically monitor sodium levels in high-risk patients starting duloxetine therapy.
- If hyponatremia develops, dose reduction, discontinuation of the medication, or fluid restriction might be necessary, depending on the severity of the condition and the patient's overall health status 2. The most recent study available 2 compared the incidence rate of hyponatremia associated with different SSRI/SNRI molecules, and found that duloxetine had a higher incidence rate of hyponatremia compared to other molecules. Identified risk factors for hyponatremia include:
- Age, with a large increase of incidence rate from 75 years old 2
- Female gender 2 It is essential to be aware of these potential risks and to monitor patients closely when starting duloxetine therapy, especially in high-risk populations.