A bipolar patient is prescribed lithium carbonate 600 mg daily. Before discharge, what statement best educates the patient about this medication?

• A. This medication has the potential for both psychological and physical dependence.
• B. Lithium carbonate has the adverse side effect of possibly causing weight loss.
• C. It is important to maintain a normal salt intake while avoiding diuretics.
• D. The earliest signs of lithium toxicity would be confusion and coarse hand tremors.

Answer: (C)

Lithium’s effect in bipolar disorder comes with a narrow therapeutic window, and how the kidneys handle lithium is closely tied to sodium balance. Keeping a normal salt intake helps stabilize lithium levels because sodium and lithium compete for reabsorption in the kidneys. If salt intake is too low or you become dehydrated, the kidneys reabsorb more lithium, increasing toxicity risk. Diuretics can cause loss of sodium, which also raises lithium levels, so they should be avoided or used only under careful supervision.

Lithium does not cause dependence, and it typically does not lead to weight loss; weight gain is more common. Early toxicity signs are often mild tremors, thirst, and polyuria, with confusion and coarse hand tremors indicating more advanced toxicity. So the key discharge message is to maintain normal salt intake, stay hydrated, and avoid diuretics.