Talks
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Resident
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Internal Medicine
Academic Level (Author 2)
Resident
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Internal Medicine
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Internal Medicine
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Faculty
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Internal Medicine
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Oral Presentation
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Community/Public Health
Abstract Type
Case Report
Abstract
Background: Abiraterone, a cytochrome P17 (17a-hydroxylase/C17,20-lyase) inhibitor used in metastatic castration-resistant prostate cancer (CRPC), suppresses androgen and cortisol synthesis, leading to elevated ACTH and accumulation of mineralocorticoid precursors such as 11-deoxycorticosterone and corticosterone, both possessing potent mineralocorticoid activity1,2,3. Concomitant prednisone is recommended to prevent this cascade, as its omission can lead to clinically significant mineralocorticoid excess manifesting as severe hypokalemia, hypertension, and fluid retention4. This preventable complication remains underrecognized, particularly in elderly patients who are frequently exposed to polypharmacy. Here, we report a patient with metastatic CRPC on abiraterone therapy who presented with acute wrist pain, hypokalemia, hypertension, and lower extremity edema.
Case Presentation: An 82-year-old man with metastatic CRPC on abiraterone therapy presented with sudden-onset right wrist pain, generalized weakness, poorly controlled hypertension, and progressively worsening lower extremity swelling. Physical examination revealed point tenderness over the right wrist and bilateral pitting pedal edema. A venous Doppler ultrasound of the lower extremities ruled out deep vein thrombosis, while an X-ray of the right wrist demonstrated a non-displaced distal metaphyseal fracture of the right ulna, consistent with a low-energy (pathological) fracture. Initial laboratory evaluation revealed severe hypokalemia (2.4 mmol/L), and a 12-lead electrocardiogram showed a prolonged QT interval with prominent U waves in the precordial leads, consistent with hypokalemia. Despite aggressive intravenous and oral potassium supplementation, his hypokalemia persisted. Serial history-taking and medication reconciliation with his oncologist, primary care physician (PCP), and family revealed that the patient had inadvertently omitted prednisone prescribed alongside abiraterone and had been taking abiraterone monotherapy. This raised clinical suspicion that abiraterone was the cause of his resistant hypokalemia. The medication was held, and prednisone 5 mg twice daily was initiated, resulting in rapid normalization of potassium levels and improvement in blood pressure and edema over the next few days. Based on this observation, a Naranjo Adverse Drug Reaction score was calculated to assess the causal relationship between abiraterone and hypokalemia, yielding a score of 9, indicating abiraterone as the likely cause of his resistant hypokalemia.5The patient experienced an uneventful recovery with conservative fracture management using immobilization and splinting and was later discharged with appropriate follow-up arranged with his oncologist and PCP.
Conclusion: This case highlights the importance of prednisone co-administration in patients receiving abiraterone to prevent mineralocorticoid excess, which can present as resistant hypokalemia, hypertension, fluid retention, and muscle weakness, potentially increasing fracture risk in osteoporotic patients. Clinicians should maintain a high index of suspicion for these adverse effects, particularly when steroid coverage is omitted. Early recognition is critical, as the condition may mimic primary aldosteronism or be mistaken for diuretic or renal causes. This case highlights the impact of polypharmacy, where the omission of prednisone in a complex medication regimen transformed a standard, evidence-based therapy into a high-risk situation, resulting in severe hypokalemia. It also underscores the importance of thorough medication reconciliation, clear documentation of co-prescribed drugs, and comprehensive patient and caregiver education regarding the purpose and timing of each medication to enhance safety in polypharmacy settings6.
Recommended Citation
Singh, Ripudaman; Choi, Seokwon; Tijani, Aramide; and Bello, Fatimah, "Abiraterone-Induced Resistant Hypokalemia and Hypertension: A Preventable Complication" (2026). Research Symposium. 1.
https://scholarworks.utrgv.edu/somrs/2026/talks/1
Included in
Abiraterone-Induced Resistant Hypokalemia and Hypertension: A Preventable Complication
Background: Abiraterone, a cytochrome P17 (17a-hydroxylase/C17,20-lyase) inhibitor used in metastatic castration-resistant prostate cancer (CRPC), suppresses androgen and cortisol synthesis, leading to elevated ACTH and accumulation of mineralocorticoid precursors such as 11-deoxycorticosterone and corticosterone, both possessing potent mineralocorticoid activity1,2,3. Concomitant prednisone is recommended to prevent this cascade, as its omission can lead to clinically significant mineralocorticoid excess manifesting as severe hypokalemia, hypertension, and fluid retention4. This preventable complication remains underrecognized, particularly in elderly patients who are frequently exposed to polypharmacy. Here, we report a patient with metastatic CRPC on abiraterone therapy who presented with acute wrist pain, hypokalemia, hypertension, and lower extremity edema.
Case Presentation: An 82-year-old man with metastatic CRPC on abiraterone therapy presented with sudden-onset right wrist pain, generalized weakness, poorly controlled hypertension, and progressively worsening lower extremity swelling. Physical examination revealed point tenderness over the right wrist and bilateral pitting pedal edema. A venous Doppler ultrasound of the lower extremities ruled out deep vein thrombosis, while an X-ray of the right wrist demonstrated a non-displaced distal metaphyseal fracture of the right ulna, consistent with a low-energy (pathological) fracture. Initial laboratory evaluation revealed severe hypokalemia (2.4 mmol/L), and a 12-lead electrocardiogram showed a prolonged QT interval with prominent U waves in the precordial leads, consistent with hypokalemia. Despite aggressive intravenous and oral potassium supplementation, his hypokalemia persisted. Serial history-taking and medication reconciliation with his oncologist, primary care physician (PCP), and family revealed that the patient had inadvertently omitted prednisone prescribed alongside abiraterone and had been taking abiraterone monotherapy. This raised clinical suspicion that abiraterone was the cause of his resistant hypokalemia. The medication was held, and prednisone 5 mg twice daily was initiated, resulting in rapid normalization of potassium levels and improvement in blood pressure and edema over the next few days. Based on this observation, a Naranjo Adverse Drug Reaction score was calculated to assess the causal relationship between abiraterone and hypokalemia, yielding a score of 9, indicating abiraterone as the likely cause of his resistant hypokalemia.5The patient experienced an uneventful recovery with conservative fracture management using immobilization and splinting and was later discharged with appropriate follow-up arranged with his oncologist and PCP.
Conclusion: This case highlights the importance of prednisone co-administration in patients receiving abiraterone to prevent mineralocorticoid excess, which can present as resistant hypokalemia, hypertension, fluid retention, and muscle weakness, potentially increasing fracture risk in osteoporotic patients. Clinicians should maintain a high index of suspicion for these adverse effects, particularly when steroid coverage is omitted. Early recognition is critical, as the condition may mimic primary aldosteronism or be mistaken for diuretic or renal causes. This case highlights the impact of polypharmacy, where the omission of prednisone in a complex medication regimen transformed a standard, evidence-based therapy into a high-risk situation, resulting in severe hypokalemia. It also underscores the importance of thorough medication reconciliation, clear documentation of co-prescribed drugs, and comprehensive patient and caregiver education regarding the purpose and timing of each medication to enhance safety in polypharmacy settings6.
