Titrate MRA dose to raise renin in PA patients with uncontrolled hypertension
STEP 1 — Gather Information
Confirm primary aldosteronism diagnosis, current MRA type and dose, seated morning blood pressure, plasma renin activity (PRA) or direct renin concentration (DRC), serum potassium, and estimated glomerular filtration rate (eGFR). Document these values to assess whether hypertension is uncontrolled and renin is suppressed.
STEP 2 — Rule In / Rule Out
If blood pressure is above target (e.g., ≥130/80 mmHg) AND renin is suppressed (PRA <0.5 ng/mL/h or DRC <4 mU/L), proceed to Step 3; otherwise, evaluate medication adherence, lifestyle factors, or consider adding other antihypertensive agents before increasing MRA dose.
STEP 3 — Classify or Stratify
Estimate the MRA dose increase based on current renin level: if renin is very low (PRA <0.2 ng/mL/h or DRC <2 mU/L), plan to increase spironolactone by 25–50 mg/day; if renin is low but detectable (PRA 0.2–0.5 ng/mL/h or DRC 2–4 mU/L), plan to increase by 25 mg/day; for eplerenone, use equivalent potency increments. Calculate the specific dose increment and prepare the new prescription.
STEP 4 — Decide
Increase the MRA dose as calculated, counsel the patient on adherence and dietary sodium restriction, and schedule reassessment of blood pressure and renin in 8–12 weeks.
Clinical Guardrails / Mimics / Pitfalls
Do not increase MRA if blood pressure is already at target; avoid doses that risk hyperkalemia (monitor K+ and creatinine); do not rely on renin rise alone if BP remains uncontrolled—add other agents; be cautious in CKD where renin response may be blunted.
Concrete Clinical Example
A 60-year-old woman with bilateral PA on spironolactone 50 mg daily presents with BP 148/92 mmHg, PRA 0.15 ng/mL/h, K+ 4.6 mmol/L, eGFR 68 mL/min/1.73m². Increase spironolactone to 75 mg daily and recheck BP and renin in 10 weeks.
Source: Primary Aldosteronism: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2025, DOI: 10.1210/clinem/dgaf284
TODO: consider adding scripts/calc.py for the endo-pa-mra-titrate-renin calculator