Imipramine Inappropriate antidiuretic hormone secretion

After 7-12 days ot treatment with imipramine hydrochloride (SOmg tid) for acute depression, a 54-year-old woman became progressively weak, irritable. restless and confused. Serum sodium concentration was found to be 1 19 mmol/L. serum potassium 3.1 mmol/L, serum chloride 85 mmol/L, serum osmolality 245 mmol/kg and urine osmolality 460 mmol/kg. Imipramine­induced syndrome of inappropriate antidiuretic hormone (ADH) secretion was suspected, and other possible causes of increased ADH secretion were excluded. Imipramine was discontinued and fluids restricted. Symptoms improved during the next 24-72 hours, and at 72 hours, all serum and urine determinations were within the normal range. T~eatment with doxepin 100 mg/ day was started, and electrolytes were stdl normal after B weeks.

Although inappropriate ADH secretion has been reported after treatment with tricyclic and tetracyclic antidepressants and MAOls, this is the first case in which imipramine seems to be involved.

Awareness is needed of the possibility and symptoms of this effect, and serum sodium levels should be determined in patients on antidepressants, Parker, WA .. Drug Intelligence and Clinical Pharmacy 18 890 (NOV 1984)

B Reactions 24 Nov 1984 0157-7271/84/1124..(J()(J8/0$Of.OO/O @ ADiS PresS