Late-onset Complications in a Chronic Proton Pump Inhibitor User: Electrolyte Abnormalities and a Diagnostic Approach

This case presents an unusual presentation of severe hypocalcemia, hypomagnesemia, and hypokalemia that suddenly developed in a patient with a prior 15-year history of proton pump inhibitor (PPI) use with no prior complications. The patient developed acute onset of persistent tingling and numbness in her fingertips followed by acute confusion and perioral tingling. Upon hospitalization, she was found to have severe hypocalcemia, hypomagnesemia, and hypokalemia and required IV electrolyte repletion. This episode recurred, prompting the discontinuation of her PPI therapy. This unusual timing prompted an extensive workup to exclude alternative etiologies of hypocalcemia. Ultimately, PPI-induced hypomagnesemia was identified as the primary driver of the patient's electrolyte abnormalities. This case serves dual teaching points. First, it underscores the importance of recognizing that refractory hypocalcemia and hypokalemia can often be linked to untreated hypomagnesemia so that timely diagnosis, effective management, and minimization of hospitalizations can be ensured. Second, this case highlights the unusual timing of symptomatic hypomagnesemia and subsequent hypocalcemia and hypokalemia despite years of prior PPI usage without prior known complications.