A nurse is reviewing the laboratory results of a client who is prescribed lithium 300 mg three times daily. The client’s serum lithium level is 1.4 mEq/L. Which of the following actions should the nurse take?

Choice A reason: Sodium intake does affect lithium levels because lithium and sodium compete for reabsorption in the kidneys. However, increasing sodium intake is not the immediate intervention for a client with a lithium level of 1.4 mEq/L, which is above the therapeutic range (0.6–1.2 mEq/L). The priority is to prevent further administration and notify the provider. Choice B reason: Simply documenting and reassessing later delays necessary intervention. Lithium toxicity can progress quickly, and waiting 4 hours without action risks worsening symptoms. This option does not address the immediate safety concern. Choice C reason: A level of 1.4 mEq/L indicates early lithium toxicity. The nurse should hold the next dose to prevent further accumulation and notify the provider immediately. This action ensures timely medical evaluation and prevents progression to severe toxicity, which can cause neurological and cardiovascular complications. Choice D reason: Continuing the medication as prescribed would worsen toxicity. Administering lithium at this level is unsafe and contraindicated. This option disregards the abnormal laboratory finding and places the client at risk.