ODP442 Posaconazole-induced Pseudohyperaldosteronism (PIPH) in Patient Treated for Acute Myeloid Leukemia

CASE SUMMARY: A 62-year-old Caucasian female presented to our institute with mechanical fall complicated by cervical spine fracture. She had known history of essential hypertension and recently diagnosed acute myeloid leukemia with myelodysplasia related changes (AML-MRC). She had undergone induction chemotherapy with combination of daunorubicin and cytarabine, resulting in chemotherapy induced prolonged pancytopenia. She was initially started on primary prophylaxis with fluconazole, but was switched to voriconazole due to persistent neutropenia. Patient then developed bilateral upper and lower extremity erythematous popular rash on voriconazole. Decision at that time was to switch to Posaconazole 300 mg orally daily. Three months after initiating Posaconazole, patient presented with severe hypokalemia (2.1 mmol/L) and hypertension. Previously her blood pressure was under control with amlodipine, lisinopril and nadolol. Hypokalemia persisted despite aggressive oral and intermittent intravenous potassium replacement therapy. No sources of potassium loss were identified on clinical history. She had persistently elevated blood pressure (systolic blood pressure of 150-180 mmHg) despite being on her home anti-hypertensive regimen. Further work up showed undetectable plasma aldosterone of less than 1 ng/dL (normal < 28 ng/dL) and plasma renin activity level was suppressed to 0.14 ng/mL/h (normal 0.25–5.82 ng/mL/h) with concurrent potassium of 2.9 mmol/L (normal 3.5-5.3 mmol/l). Diagnosis of pseudohyperaldosteronism was made at this time. Posaconazole gradually stopped and eplerenone 25 mg daily was commenced to selectively block mineralocorticoids receptors to control blood pressure. Subsequently hypokalemia resolved after stopping posaconazole and blood pressure normalized with her original home anti-hypertensive regimen. Eplerenone was eventually stopped. Her potassium level and blood pressure remained normal 2 weeks after discharge. DISCUSSION: Recent studies have shown the presentation of hypokalemia and hypertension in nearly a quarter of patients on Posaconazole. The clinical presentation of hypokalemia and hypertension with apparent mineralocorticoid excess was evident in our patient and was consistent with posaconazole-induced pseudohyperaldosteronism (PIPH). Posaconazole interference with the steroid synthesis pathway has been described in various literature. Both cortisol and aldosterone activate aldosterone receptors. In the case of posaconazole, excess mineralocorticoid effect is due to relative selectivity of posaconazole for 11ΒHSD2 inhibition. 11ΒHSD2 inhibition causes increased serum cortisol level by preventing the conversion to inactive cortisone. The high cortisol level cross-reacts with the mineralocorticoid receptor leading to apparent mineralocorticoid excess with low serum aldosterone level and low plasma renin activity. The degree of pseudohyperaldosterone effect on systolic blood pressure and hypokalemia has been strongly associated with serum posaconazole level in some studies. Our patient had resolution of uncontrolled hypertension and hypokalemia after withholding the posaconazole and short term treatment with selective mineralocorticoid receptor blocker. CONCLUSION: Early diagnosis and to allow for early intervention with cessation of the offending agent or treatment with mineralocorticoid antagonists, such as spironolactone and eplerenone is necessary in PIPH. Presentation: No date and time listed