Which action should the nurse implement to assess the effectiveness of amlodipine?

A) Note the client's serum calcium levels: While calcium levels can be relevant in some contexts, they are not directly related to assessing the effectiveness of amlodipine, which is primarily used as an antihypertensive medication. B) Review the client's intake and output: This action is not specific to assessing the effectiveness of amlodipine. While monitoring I&O is important in general nursing care, it does not directly indicate how well the medication is working. C) Measure the client's blood pressure: This is the correct action. Amlodipine is a calcium channel blocker used primarily to manage hypertension. The effectiveness of the medication can be directly assessed by measuring the client's blood pressure and observing any reduction in levels. D) Monitor the client's serum electrolytes: While it's important to monitor electrolytes in clients taking various medications, it is not the most direct way to assess the effectiveness of amlodipine. Blood pressure measurement is more relevant for evaluating the drug's effectiveness.