Renal tubular defects from antidepressant use in an older adult - An uncommon but reversible adverse drug effect

Adverse drug reactions are common and contribute to significant mortality and morbidity. We report a case study of an elderly woman who manifested with uncommon reversible renal tubular defects following the use of escitalopram. She was initially seen for worsening symptoms of depression and started on escitalopram in addition to her regular medications, which included donepezil, hydrochlorothiazide and mirtazapine. Three weeks later, she became increasingly confused and manifested recurrent falls. Laboratory evaluation showed hyponatraemia and evidence of renal tubular absorption defects. The patient's symptoms and laboratory abnormalities improved upon discontinuation of escitalopram as well as of mirtazapine and hydrochlorthiazide. This case illustrates the possibility of rare but reversible renal tubular defects associated with the use of antidepressant medications.