Which of the following glucocorticoids has the longest biological duration of action?
- A Hydrocortisone
- B Dexamethasone ✓
- C Methylprednisolone
- D Prednisolone
Correct answer: B. Dexamethasone
Explanation
Dexamethasone is a long-acting glucocorticoid with a biological half-life of 36 to 54 hours, compared with 8 to 12 hours for short-acting agents like hydrocortisone and 12 to 36 hours for intermediate-acting prednisolone and methylprednisolone. Its long duration reflects slow tissue clearance and high receptor affinity. This property makes it suitable for once-daily dosing and the overnight dexamethasone suppression test, but it carries the greatest risk of HPA axis suppression per milligram.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.