Objective: We present a case of acute intermittent porphyria with accompanying euvolemic hyponatremia from elevated ADH triggered by an implanted hormonal contraceptive device.
Case description: A 19-year-old African-American female with history of childbirth two months prior presented to the emergency department of Grady Memorial Hospital with vague but severe back pain and found with marked hyponatremia of 125mEq/L. Serum sodium level decreased to 113mEq/L after volume resuscitation with 0.9% sodium chloride. The patient experienced progressive decline in mental status and a single generalized tonic clonic seizure. Patient was admitted to intensive care unit and improved with administration of 3% sodium chloride. Extensive evaluation for etiology of euvolemic hyponatremia was initially unremarkable, and patient was managed with free water restriction, hypertonic sodium chloride, vasopressin receptor antagonists, and antihypertensive medications. Empiric removal of a recently inserted etonogestrel implant was performed with resolution of patient’s symptoms. Approximately 2 weeks following hospital discharge, the send-out lab for urine porphobilinogen was found to be notably elevated.
Conclusion: We stress the importance of considering the diagnosis of AIP in patients presenting with back or abdominal pain, hyponatremia and altered mental status who are reproductive age females and using implanted hormonal contraceptive devices. Appropriate supportive treatment and removal of the implant is required to prevent morbidity and life-threatening consequences.