A client who is newly diagnosed with diabetes insipidus (DI) is receiving a synthetic vasopressin intravenously. Which side effect of vasopressin reported by the client should the nurse report to the healthcare provider?

A. Worsening headache: Vasopressin is used to manage diabetes insipidus by reducing excessive urine output and increasing water reabsorption. A worsening headache could indicate an adverse reaction or side effect such as water intoxication or an increase in intracranial pressure, which requires immediate attention from the healthcare provider. B. Low urine specific gravity: Vasopressin should increase urine specific gravity by concentrating the urine. A low urine specific gravity would indicate that the medication is not effectively concentrating the urine, but it is not an immediate or severe side effect needing urgent reporting. C. Polyuria: Polyuria (excessive urine output) is a characteristic of diabetes insipidus, and vasopressin is intended to reduce this symptom. If polyuria persists despite treatment, it suggests that the medication is not working as intended but does not indicate a severe side effect. D. Polydipsia: Polydipsia (excessive thirst) can occur in diabetes insipidus and may continue despite treatment with vasopressin. While it indicates ongoing symptoms, it is not a severe side effect of the medication that would require urgent reporting to the healthcare provider.