Select Medical Agent for Bilateral Adrenal Disease PA

STEP 1 — Gather Information

Confirm bilateral adrenal disease via adrenal venous sampling (AVS) showing lateralization ratio <3:1 or cortisol-corrected aldosterone ratio bilateral, or CT demonstrating bilateral hyperplasia/nodularity, or genetic testing for glucocorticoid-remediable aldosteronism (GRA). Collect baseline serum potassium, creatinine, eGFR, and review for contraindications to spironolactone (e.g., pregnancy, severe renal impairment, hyperkalemia risk, prior gynecomastia/intolerance). Document current medications, especially ACE inhibitors, ARBs, or potassium-sparing agents.

STEP 2 — Rule In / Rule Out

If AVS, CT, or genetic testing confirms bilateral adrenal disease (idiopathic hyperplasia, bilateral adenoma, or GRA), proceed to Step 3; if testing indicates unilateral disease (e.g., AVS lateralization ratio >4:1 with cortisol correction), refer for surgical evaluation (outside scope of this skill).

STEP 3 — Classify or Stratify

Assess tolerance and contraindications to spironolactone: if no history of gynecomastia, menstrual disturbances, severe renal dysfunction (eGFR <30 mL/min/1.73 m²), or hyperkalemia risk, classify as spironolactone‑eligible; if any contraindication or prior intolerance exists, classify as eplerenone‑candidate.

STEP 4 — Decide

For spironolactone‑eligible patients, initiate therapy at 12.5–25 mg PO once daily, titrate upward to 100 mg daily based on blood pressure, potassium, and tolerability; for eplerenone‑candidate patients, start 25 mg PO twice daily, titrate up to 50 mg twice daily as needed. Re‑check serum potassium and creatinine within 1–2 weeks of initiation or dose change.

Clinical Guardrails / Mimics / Pitfalls

Monitor for hyperkalemia, particularly when spironolactone or eplerenone is combined with ACE inhibitors, ARBs, or NSAIDs; avoid in pregnancy due to anti‑androgenic effects; recognize that spironolactone may cause dose‑dependent gynecomastia or menstrual irregularities, whereas eplerenone has a lower incidence of these effects but may be less potent for blood pressure control in some patients. Do not use MR antagonists in patients with severe hyperkalemia (K⁺ >5.5 mmol/L) or advanced renal failure without nephrology consultation.

Concrete Clinical Example

A 48‑year‑old woman presents with resistant hypertension (BP 168/102 mm Hg on three agents) and spontaneous hypokalemia (K⁺ 3.1 mmol/L). ARR is elevated, AVS shows bilateral aldosterone secretion (lateralization ratio 2:1), CT reveals bilateral adrenal hyperplasia, and genetic testing is negative for GRA. Baseline K⁺ 4.2 mmol/L, creatinine 0.8 mg/dL. She has no prior MR antagonist use. Start spironolactone 25 mg PO daily; after 10 days, K⁺ is 4.6 mmol/L and BP improved to 148/92 mm Hg. Increase to 50 mg daily; after another 2 weeks, K⁺ remains 4.8 mmol/L and BP is 138/86 mm Hg.

Source: The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, doi:10.1210/jc.2015-4061