If a patient on Lithium sweats heavily, what adjustment should be made?

• A. Increase potassium
• B. Increase sodium
• C. Decrease fluids
• D. Decrease sodium

Answer: (B)

When lithium is being excreted by the kidneys, its fate tracks closely with sodium balance. Sweating causes loss of sodium, and if sodium becomes low, the kidneys reclaim more lithium to help maintain volume. That increased lithium reabsorption raises lithium levels in the blood, heightening the risk of toxicity. So, to prevent this, increasing sodium intake helps promote lithium excretion and keeps levels steadier, especially with heavy sweating. Pair this with adequate fluids to avoid dehydration. Potassium isn’t the main factor here, and decreasing fluids or decreasing sodium would worsen the risk of lithium toxicity.