A patient with known Addison's disease collapses in the dental chair with hypotension, weakness and vomiting. What is the definitive emergency drug?

Correct answer: A. Intravenous hydrocortisone 100 mg

• A. Correct. This is an ADRENAL (Addisonian) CRISIS — acute glucocorticoid insufficiency. Definitive management is immediate parenteral corticosteroid: hydrocortisone 100 mg IV/IM in adults, plus IV fluids (normal saline), oxygen, supine positioning with legs elevated, and activation of EMS.
• B. Nitroglycerin is a vasodilator and would deepen the hypotension — it is contraindicated here.
• C. Epinephrine is the drug for anaphylaxis. It will transiently support blood pressure but does not correct the underlying cortisol deficiency.
• D. Oral glucose treats hypoglycemia. Hypoglycemia can accompany adrenal crisis, but glucose alone does not reverse the crisis — and an obtunded/vomiting patient should not receive oral agents.

Note: Chronic Addison's is managed with daily corticosteroid replacement; the ACUTE crisis needs IV hydrocortisone. Consider supplemental steroid coverage for major stressful procedures in these patients.