A nurse is providing discharge teaching to a client who has bipolar disorder and will be discharged with a prescription for lithium. The nurse should teach the client that which of the following factors puts her at risk for lithium toxicity?

Choice A reason: Eating 2 to 3 grams of sodium-containing foods daily is not a risk factor for lithium toxicity. In fact, maintaining a consistent sodium intake is important because lithium and sodium compete for reabsorption in the kidneys. A stable sodium intake helps prevent fluctuations in lithium levels. Sudden sodium restriction, not normal intake, increases risk of toxicity. Choice B reason: Avoiding NSAIDs actually reduces the risk of lithium toxicity. NSAIDs can decrease renal clearance of lithium, leading to elevated serum levels. By avoiding NSAIDs, the client is protecting against toxicity rather than increasing risk. Choice C reason: Drinking 2 liters of liquids daily is appropriate and protective. Adequate hydration helps maintain renal clearance of lithium and prevents accumulation. Dehydration is a major risk factor for lithium toxicity, so consistent fluid intake is encouraged. Choice D reason: Running 4 miles outdoors every afternoon is the correct risk factor. Vigorous exercise, especially outdoors, increases sweating and fluid loss, which can lead to dehydration and sodium depletion. Both dehydration and low sodium levels reduce renal clearance of lithium, causing serum levels to rise and increasing the risk of toxicity. Clients on lithium must avoid excessive fluid loss and maintain hydration to prevent dangerous accumulation.