Pharmacology · patient case question
For Patient C — which of these agents is a MINERALOCORTICOID rather than a glucocorticoid?
Patient case: Five patients, five medical problems
Patient: Five separate patients in one session
Chief Complaint: A: mid-appointment shakiness. B: routine care. C: reviewing a medication list. D: an occupational health question. E: a child brought in by a parent.
Background: A: type 1 diabetes, took her insulin but skipped breakfast. B: 40-pack-year smoker with a chronic productive cough. C: on long-term corticosteroid therapy. D: a dental assistant with a new serology report. E: 6-year-old with sore throat, fever and a rash.
Findings: A: shaky, sweating, confused but conscious and able to swallow; capillary glucose 54 mg/dL. B: barrel chest, prolonged expiration. E: a sandpaper-textured rash, and a tongue with a white coating through which swollen red papillae project.
Show answer and explanation
Correct answer: B. Fludrocortisone
- A. Triamcinolone is a GLUCOCORTICOID. In dentistry it is best known as triamcinolone acetonide in an adhesive oral paste for ulcerative and erosive mucosal disease.
- B. CORRECT. FLUDROCORTISONE is the mineralocorticoid used clinically. It acts on the aldosterone receptor in the distal nephron to retain sodium and water and excrete potassium, and it is the replacement given in ADDISON DISEASE alongside a glucocorticoid.
- C. Dexamethasone is a long-acting, high-potency GLUCOCORTICOID with essentially NO mineralocorticoid activity — which is what makes it the agent of choice for reducing post-operative oedema and trismus after third molar surgery, where sodium retention would be an unwanted effect.
- D. Prednisone is a GLUCOCORTICOID and the standard oral agent; it is a prodrug converted to prednisolone in the liver. Note that HYDROCORTISONE (cortisol itself) has substantial mineralocorticoid activity as well as glucocorticoid activity, which is exactly why it is the drug given intravenously for adrenal crisis.
Note: Glucocorticoid adverse effects to expect and to distinguish from the mineralocorticoid ones: HYPERglycaemia (not hypo — a common exam trap), adrenal suppression, osteoporosis, posterior subcapsular cataract and raised intraocular pressure, thin fragile skin, impaired wound healing, immunosuppression, peptic ulceration, mood change and the cushingoid habitus. ADRENAL SUPPRESSION is the one that determines whether supplemental steroid cover is needed before a surgical procedure.