A nurse is teaching a client who has bipolar disorder about lithium. Which of the following statements should the nurse include in the teaching?

Weight gain is a common side effect of lithium therapy but not necessarily an indication of lithium toxicity. Lithium toxicity is more closely associated with symptoms such as nausea, vomiting, diarrhea, tremors, confusion, and ataxia. Therefore, while it is important to monitor for adverse effects, weight gain alone does not signify toxicity. Choice B reason: Lithium is not considered addictive, and there is no standard recommendation to discontinue it after six months. It is typically used as a long-term treatment for bipolar disorder to manage and prevent mood episodes. This statement is inaccurate and could lead to improper discontinuation of a necessary medication. Choice C reason: While lithium can cause polyuria (excessive urination), prescribing a diuretic is not a standard solution. Diuretics can actually increase lithium levels in the blood, raising the risk of toxicity. Management of polyuria typically involves other strategies such as dose adjustment or switching medications, but not necessarily diuretics. Choice D reason: Monitoring lithium levels is crucial in managing therapy because of the narrow therapeutic index. Regular blood tests are needed to ensure that lithium levels remain within a safe and effective range. This practice helps to prevent both subtherapeutic dosing and toxicity, making this statement correct and vital for patient education.