Q. A 35-year-old male presents to the emergency department with weakness, fatigue, and dizziness for the past few days. He has a history of autoimmune diseases and was on long-term glucocorticoid therapy, which he recently stopped. On examination, he appears lethargic, has hyperpigmentation of his skin, and has low blood pressure. Lab results show hyponatremia, hyperkalemia, and a low serum cortisol level. The patient is diagnosed with adrenocortical insufficiency. Which of the following is the most appropriate management for this patient?