A nurse is caring for a client who has benign prostate hyperplasia (BPH) and a new prescription for doxazosin IR. Which of the following actions should the nurse plan to take first?

A. "Instruct the client to limit caffeine": While caffeine can irritate the bladder, which may worsen symptoms of BPH, the priority action when starting doxazosin is addressing the potential for orthostatic hypotension. B. "Instruct the client to report headache": Headache is a potential side effect of doxazosin, and it is important to monitor for this symptom. However, the priority action for this client is to manage the potential for dizziness or fainting due to the first-dose effect. C. "Measure the client's intake and output": Measuring intake and output is important for monitoring kidney function and fluid balance, but it is not the first priority when starting doxazosin. D. "Administer the medication at bedtime": Doxazosin can cause orthostatic hypotension, particularly after the first dose, leading to dizziness or fainting. Administering the medication at bedtime minimizes the risk of these side effects by reducing the chance of the client experiencing dizziness while standing.