From the Guidelines
Gabapentin can cause hyponatremia, and patients taking this medication should be monitored for symptoms of low sodium levels, especially if they have underlying conditions like SIADH or are taking diuretics 1. When managing hyponatremia in patients taking gabapentin, it is essential to consider the underlying cause and severity of the condition.
- For patients with hypovolemic hyponatremia, plasma volume expansion with saline solution and correction of the causative factor are recommended 1.
- For patients with hypervolemic hyponatremia, attainment of a negative water balance is crucial, and non-osmotic fluid restriction may be helpful in preventing further decreases in serum sodium levels 1.
- However, fluid restriction is often ineffective in improving serum sodium concentration, and alternative treatments like vaptans may be considered 1. Some key points to consider when managing hyponatremia in patients taking gabapentin include:
- Regular sodium level checks are recommended, especially when starting or adjusting gabapentin dosages 1.
- Gabapentin dose reduction or discontinuation may be necessary if hyponatremia develops 1.
- Vaptans, such as tolvaptan, may be effective in improving serum sodium concentration in patients with hyponatremia, but their safety and efficacy have only been established for short-term treatments 1. It is crucial to educate patients about hyponatremia symptoms and ensure proper hydration without excessive water intake while taking gabapentin 1. In severe cases of hyponatremia, hypertonic sodium chloride administration may be considered, but it should be limited to patients with life-threatening manifestations, and serum sodium concentration should not increase more than 8 mmol/L per day to avoid central pontine myelinolysis 1.
From the FDA Drug Label
Metabolism and nutrition disorders: hyponatremia The FDA drug label for gabapentin mentions hyponatremia as a potential adverse reaction, reported during postmarketing use of the drug 2.
- Hyponatremia is listed under Metabolism and nutrition disorders. However, the frequency of this reaction is not provided, and a causal relationship to drug exposure is not established.
From the Research
Gabapentin and Hyponatremia
- There is no direct evidence in the provided studies that links gabapentin to hyponatremia 3, 4, 5, 6, 7.
- However, it is known that certain medications can contribute to the development of hyponatremia, particularly those that affect the regulation of water and electrolytes in the body 3, 6.
- Gabapentinoids, including gabapentin, are frequently prescribed in individuals with chronic kidney disease (CKD), and their exclusive renal elimination warrants dose adjustments to decrease the risk of toxicity 4, 5.
- The studies provided focus on the diagnosis and management of hyponatremia 3, 6, 7, and the safe prescribing of gabapentinoids in older adults with CKD 4, 5.
- Hyponatremia is a common electrolyte disorder that can be caused by various factors, including water retention, and can lead to increased hospital stay and mortality 3.
- The management of hyponatremia depends on the underlying cause and the patient's fluid volume status, and may involve treating the underlying disease, restricting free water intake, and using medications such as vasopressin receptor antagonists or hypertonic saline 3, 6, 7.