Captopril-induced hyponatremia with irreversible neurologic damage

Area of Science:

• Nephrology
• Cardiology
• Neurology

Background:

• A 61-year-old male with congestive heart failure and hypertension was admitted with confusion and cortical blindness.
• The patient presented with a critically low serum sodium level of 114 meq/liter.

Observation:

• Captopril was initiated two weeks prior for afterload reduction, coinciding with a drop in serum sodium from 137 to 126 meq/liter.
• The patient reported excessive thirst and high water intake for over a week before hospitalization.

Findings:

• Rapid correction of hyponatremia (0.9 meq/liter per hour) did not reverse the patient's semi-comatose state.
• The patient died four days after admission due to a gastrointestinal bleed.

Implications:

• This case suggests captopril may induce thirst and severe hyponatremia, potentially leading to irreversible neurological damage.
• The findings highlight the critical need to monitor electrolytes in patients initiating captopril therapy, especially those with pre-existing conditions.
• This case underscores the potential for severe adverse events, including death, despite therapeutic interventions for drug-induced hyponatremia.