Hyponatremia following acute overdose with paroxetine

This case illustrates severe hyponatremia following an acute overdose of paroxetine. An 83-year-old woman was admitted to our hospital after an attempt to commit suicide. She had consumed an overdose of 360 mg paroxetine. The treatment was started 3 days previously with 10 mg/day because of regular suffering from obsessive and suicidal thoughts. An initial sign of overdose was excessive vomiting. Five days late she developed hyponatremia (serum sodium 112 mmol/l) with somnolence, confusion, muscle spasms, dehydration of arms and legs and slow reflexes. Ecchymoses and myxoedema were also observed. Treatment included fluid restriction and sodium chloride infusion. Levothyroxin was prescribed and the hyponatremia resolved.