From the Guidelines
Patients taking lithium should maintain consistent sodium and fluid intake to prevent lithium toxicity, and regular blood tests are essential to monitor lithium levels, which should typically be maintained between 0.6-1.2 mEq/L depending on the condition being treated. To minimize the risk of lithium toxicity, it is crucial to avoid sudden changes in salt consumption, as decreased sodium can increase lithium levels while increased sodium can reduce its effectiveness 1. Staying well-hydrated with 2-3 liters of fluid daily is also important, especially during hot weather, illness, or exercise. Additionally, caffeine should be limited as it increases lithium excretion and may reduce therapeutic effects, and alcohol should be avoided as it can worsen lithium side effects and alter hydration status. Some medications like NSAIDs (ibuprofen, naproxen), diuretics, and ACE inhibitors can increase lithium levels and should be used cautiously under medical supervision. Maintaining consistent calcium intake is also important as lithium can affect calcium metabolism. Regular monitoring of GFR, electrolytes, and drug levels is recommended for people taking potentially nephrotoxic agents such as lithium 1. These precautions are important because lithium has a narrow therapeutic window, meaning the difference between effective and toxic doses is small, and dietary factors can significantly impact how lithium is processed by the kidneys and retained in the body. Key considerations for patients taking lithium include:
- Maintaining consistent sodium and fluid intake
- Avoiding sudden changes in salt consumption
- Staying well-hydrated
- Limiting caffeine and avoiding alcohol
- Using certain medications cautiously under medical supervision
- Maintaining consistent calcium intake
- Regularly monitoring lithium levels, GFR, electrolytes, and drug levels.
From the FDA Drug Label
Lithium decreases sodium reabsorption by the renal tubules which could lead to sodium depletion. Therefore, it is essential for the patient to maintain a normal diet, including salt, and an adequate fluid intake (2500-3000 mL) at least during the initial stabilization period Decreased tolerance to lithium has been reported to ensue from protracted sweating or diarrhea and, if such occur, supplemental fluid and salt should be administered.
The patient should maintain a normal diet, including salt, and have an adequate fluid intake of at least 2500-3000 mL during the initial stabilization period to avoid sodium depletion.
- Key considerations:
- Maintain adequate salt intake
- Ensure adequate fluid intake
- Monitor for signs of sodium depletion 2
From the Research
Dietary Interactions with Lithium Administration
- Lithium clearance is affected by dietary sodium intake, with lower sodium intake leading to decreased lithium clearance and potentially increased lithium levels 3, 4.
- A low-sodium diet can increase the risk of lithium toxicity, particularly in patients with renal insufficiency 5.
- Regulation of sodium chloride intake can help stabilize serum lithium concentrations, as demonstrated in a case report where adjusting sodium chloride intake helped maintain therapeutic lithium levels 6.
- Dietary patterns have been associated with plasma lithium levels, with higher intakes of certain foods such as potatoes, leafy vegetables, and fruits, and lower intakes of others like pasta, rice, and sweets, being linked to higher lithium levels 7.
- Alcohol intake has also been positively associated with lithium levels, although the mechanism is unclear 7.
- Renal function, particularly in individuals with slightly impaired renal function, is inversely associated with lithium levels, highlighting the importance of monitoring kidney function in patients taking lithium 7.