A client being treated with desmopressin exhibits confusion and drowsiness, and reports a headache. What is the nurse's best action?

In this scenario, the nurse's best action is to take the client's vital signs. Monitoring vital signs is critical because they provide essential information about the client’s hemodynamic status and overall condition. Given that the patient is exhibiting confusion, drowsiness, and a headache, these symptoms could indicate a significant change in their health status, such as potential fluid retention or electrolyte imbalance often associated with desmopressin, which is used to manage conditions like diabetes insipidus and bedwetting.

By assessing vital signs, the nurse can ascertain if there are any abnormalities such as changes in blood pressure, heart rate, or respiratory rate, which can guide further interventions. This foundational assessment helps determine the urgency and nature of the client’s symptoms and whether immediate medical intervention is needed.

Taking vital signs before implementing interventions like contacting a physician or administering medications ensures that the nurse has a comprehensive view of the client's health, which is vital for safe clinical decision-making.