Prescribe Adult Glucocorticoid Replacement with Specific Dosing and Timing
STEP 1 — Gather Information
Confirm diagnosis of primary adrenal insufficiency (PAI) via ACTH stimulation test or morning cortisol/ACTH; assess need for glucocorticoid replacement, review current medications, pregnancy status, and presence of aldosterone deficiency requiring fludrocortisone. Action: If PAI confirmed and glucocorticoid replacement indicated, proceed to dose calculation.
STEP 2 — Rule In / Rule Out
Is the patient an adult with confirmed PAI requiring initiation of glucocorticoid replacement?
- Yes → Proceed to STEP 3.
- No → Consider alternative diagnosis or hold glucocorticoids; reassess need.
STEP 3 — Classify or Stratify
Choose glucocorticoid formulation and dosing frequency:
| Formulation | Total Daily Dose Range | Typical Split (2‑dose) | Typical Split (3‑dose) |
|---|
| Hydrocortisone | 15–25 mg | ⅔ morning, ⅓ early afternoon | ½ morning, ¼ early afternoon, ¼ late afternoon |
| Cortisone acetate | 20–35 mg | ⅔ morning, ⅓ early afternoon | ½ morning, ¼ early afternoon, ¼ late afternoon |
| Select based on patient preference, adherence, and availability. Action: Prescribe chosen total daily dose and divide as per selected schedule. | | | |
STEP 4 — Decide
Calculate individual doses: e.g., hydrocortisone 20 mg total → 10 mg morning, 5 mg early afternoon, 5 mg late afternoon (three‑dose) or 12 mg morning, 8 mg early afternoon (two‑dose). Write prescription with clear timing instructions. Action: Provide prescription and educate patient on dosing timing and stress‑dosing plan.
Clinical Guardrails / Mimics / Pitfalls
Avoid dexamethasone due to lack of mineralocorticoid activity and Cushingoid risk; do not give the largest dose in the evening to prevent insomnia; monitor for over‑replacement (weight gain, central obesity, hyperglycemia) and under‑replacement (fatigue, hypotension, hyperpigmentation, salt craving). Remember to assess and replace mineralocorticoid deficiency with fludrocortisone if aldosterone low; do not rely on ACTH levels for routine dose adjustment.
Concrete Clinical Example
A 48‑year‑man with newly diagnosed PAI (morning cortisol 80 nmol/L, ACTH 120 pmol/L) opts for hydrocortisone. Prescribed 20 mg daily: 10 mg upon awakening, 5 mg at 13:00 (≈2 h after lunch), 5 mg at 17:00. Instructed to double dose during febrile illness and carry emergency hydrocortisone kit.
Source: Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, doi:10.1210/jc.2015-1710
TODO: consider adding scripts/calc.py for the enda-adult-glucocorticoid-dosing calculator