Can Quetiapine (Seroquel) cause hyponatremia?

From the Guidelines

Yes, Quetiapine (Seroquel) can cause hyponatremia, as indicated by its association with a high risk of lowering sodium levels in the blood, with an estimated 69% probability of abstinence from normal sodium levels 1. This antipsychotic medication may cause hyponatremia through a mechanism called SIADH (Syndrome of Inappropriate Antidiuretic Hormone secretion), where the body retains too much water, diluting the sodium in the bloodstream. The risk is higher in elderly patients, those taking other medications that affect sodium levels, or individuals with certain medical conditions like heart failure or kidney disease. Some key points to consider:

• Symptoms of low sodium may include confusion, headache, nausea, muscle weakness, and in severe cases, seizures or coma.
• If you're taking Seroquel and experiencing these symptoms, contact your healthcare provider immediately.
• Regular blood tests to monitor electrolyte levels, including sodium, are often recommended for patients on Seroquel, especially when starting treatment or adjusting dosage.
• Staying properly hydrated without overhydrating and maintaining a balanced diet can help manage sodium levels while on this medication. It's essential to weigh the benefits of Quetiapine against the potential risks, particularly in vulnerable populations, and to closely monitor patients for signs of hyponatremia, as the consequences of untreated low sodium levels can be severe and impact morbidity, mortality, and quality of life.

From the FDA Drug Label

The following adverse reactions were identified during post approval of quetiapine... Adverse reactions reported since market introduction which were temporally related to quetiapine therapy include ... hyponatremia...

• Hyponatremia is listed as an adverse reaction that has been reported in patients taking quetiapine.
• The FDA drug label indicates that quetiapine may cause hyponatremia, as evidenced by post-marketing reports 2.

From the Research

Quetiapine and Hyponatremia

• Quetiapine, also known as Seroquel, has been associated with hyponatremia in some cases, as reported in the study 3.
• The study 3 describes a case of a 57-year-old woman with schizophrenia and primary polydipsia who developed extreme hyponatremia after being commenced on quetiapine 300 mg.
• The combination of primary polydipsia and SIAD (syndrome of inappropriate antidiuretic hormone secretion) can lead to life-threatening, extreme hyponatremia, as seen in the case report 3.
• Another study 4 systematically reviewed the available evidence on antipsychotic-induced hyponatremia and found that both newer atypical antipsychotics and older drugs have been associated with the development of hyponatremia.
• The incidence of hyponatremia induced by antipsychotics may be higher than currently thought, and physicians should be aware of the possibility of hyponatremia associated with the use of antipsychotics, as stated in the study 4.

Risk Factors and Patient Characteristics

• A history of polydipsia was diagnosed as positive in 67% of the cases and negative in 23% of the cases, as reported in the study 4.
• The mean age of the patients was 46 years, and 57% were male, according to the study 4.
• The diagnosis was schizophrenia in 70% of the cases, as stated in the study 4.
• The study 5 found that the risk of hyponatremia was 16-42 times higher among patients concomitantly treated with other potentially hyponatremia-inducing drugs.

Comparison with Other Medications

• The study 5 compared the incidence of hyponatremia among different psychotropic drugs and found that antipsychotic drugs, tricyclic antidepressants, and mirtazapine exhibited a significantly lower incidence of hyponatremia compared to other medications.
• The study 6 found that SSRIs do not appear to be associated with an increased risk of hyponatremia in medically-ill inpatients.
• However, another study 7 reported a case of SSRI-induced hyponatremia and highlighted the importance of prescribing SSRIs cautiously in elderly patients due to the risk of potentially severe adverse effects such as hyponatremia.