Determine Glucocorticoid Dose for Glucocorticoid-Remediable Aldosteronism
STEP 1 — Gather Information
Collect confirmed diagnosis of GRA (CYP11B1/CYP11B2 chimeric gene via genetic testing or dexamethasone suppression test), baseline seated blood pressure, serum potassium, plasma aldosterone concentration (PAC), plasma renin activity (PRA), age, weight, and for children, age- and gender-specific BP norms.
STEP 2 — Rule In / Rule Out
Rule in GRA if genetic testing shows CYP11B1/CYP11B2 chimeric gene OR dexamethasone suppression test shows ≥50% reduction in PAC after 2 mg dexamethasone overnight and clinical phenotype fits; otherwise rule out and evaluate for other PA subtypes (APA, IAH).
STEP 3 — Classify or Stratify
Stratify by age: adult (≥18 years) vs child (<18 years). For children, plan weight‑based glucocorticoid dosing and use age‑specific BP targets from published normative data.
STEP 4 — Decide
Start glucocorticoid at low dose: dexamethasone 0.125–0.25 mg PO daily at bedtime or prednisone 2.5–5 mg PO daily at bedtime. Titrate upward every 1–2 weeks based on seated BP and serum potassium, aiming for BP <140/90 mmHg (or age‑specific target) and potassium ≥3.5 mmol/L. If BP fails to normalize after reaching the maximum tolerated glucocorticoid dose (e.g., dexamethasone 0.75 mg daily) without Cushingoid signs, add an MR antagonist (spironolactone 12.5–25 mg daily). Monitor for iatrogenic Cushing’s (weight gain, facial plethora, striae, hyperglycemia) and reduce dose if occurs.
Clinical Guardrails / Mimics / Pitfalls
Avoid overtreatment causing iatrogenic Cushing’s syndrome; do not use glucocorticoid as primary therapy for unilateral adenoma amenable to laparoscopic adrenalectomy; do not neglect to add an MR antagonist when BP remains elevated despite maximal glucocorticoid; do not initiate in pregnancy without obstetric review; do not rely on glucocorticoid alone if BP remains above target after dose escalation.
Concrete Clinical Example
A 12‑year‑old boy presents with hypertension (150/95 mmHg), hypokalemia (K+ 3.0 mmol/L), suppressed PRA, elevated PAC, and genetic testing confirming a CYP11B1/CYP11B2 chimera. Start prednisone 2.5 mg nightly; after 2 weeks BP is 138/88 mmHg and K+ 3.6 mmol/L. Continue prednisone 2.5 mg nightly; no MR antagonist required.
Source: The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, https://doi.org/10.1210/jc.2015-4061
TODO: consider adding scripts/calc.py for the esa-pa-gra-gluco-dosing calculator