Why is prednisone tapered when stopping long-term therapy?

• A. To prevent rebound inflammation only
• B. To prevent immune rebound
• C. To prevent bone loss
• D. To allow pituitary ACTH production

Answer: (D)

Long-term prednisone suppresses the pituitary-adrenal (HPA) axis through negative feedback. With extended glucocorticoid use, the pituitary reduces ACTH production because the body no longer needs to make its own cortisol. If you stop suddenly, the adrenal glands don’t have enough ACTH or cortisol to meet the body's stress needs, leading to adrenal insufficiency and withdrawal-like symptoms.

Tapering gradually lets the pituitary recover and start producing ACTH again, allowing endogenous cortisol to resume production at a safe, gradual pace. That’s why the goal of tapering is to reestablish pituitary ACTH production and prevent a dangerous cortisol deficit.

Rebound inflammation, immune rebound, and bone loss are real concerns in long-term steroid therapy, but they’re not the primary reason for tapering. The essential purpose here is to prevent adrenal insufficiency by restoring ACTH production.