Endocrine Abstracts

Introduction: We report the case of a patient with corticotropic insufficiency associated with diabetes insipidus who presented to the emergency room with profound hyponatremia; a complicated situation, whose solution was hidden in the galenic form of Desmopressin.

Case report: Mrs Y. Amina, 37 years old, has been followed for 10 years for a non Langerhansian histiocytosis of pituitary location, complicated by a corticotropic insufficiency under hydrocortisone, and a diabetes insipidus under inhaled desmopressin, consulted in the emergency room for a confusional syndrome associated with nausea, vomiting and abdominal pain, the assessment carried out in urgency showed a deep hyponatremia at 118 mEq/l. This situation led to the suspicion of a decompensation of corticotropic insufficiency and the patient was put on intravenous hydrocortisone hemi succinate. The evolution was marked by the persistence of hyponatremia and the installation of hypokalemia which worsened progressively, thus signalling a corticosteroid overdose and the theory of a decompensation of corticotropic insufficiency was questioned in favor of another possibility; Desmopressin overdose, a reduction in the dose of this drug was considered, from 2 puffs per day to one puff per day, the natremia thus went to 124 mEq/l, and remained stationary. Our decision was to change the galenic form of the drug, and the patient was put on Desmopressin tablet (1 tablet in the morning and 1 tablet in the evening), the evolution was favorable with correction of the natraemia and disappearance of the symptoms.

Discussion: Used to prevent or control symptoms of central diabetes insipidus, Desmopressin is a synthetic analog of arginine vasopressin. It is more potent and much longer acting than vasopressin. Hyponatremia is a classic complication of desmopressin overdose, usually corrected by dose reduction, but in some cases, individual sensitivity is so great that even small doses can cause overdose effects. It is at this point that it is necessary to think about changing the dosage form, as the bioavailability of desmopressin varies considerably from one dosage form to another, and the fact of changing, in our case from the potent inhaled form to the oral form, has made it possible to reduce the bioavailability of the molecule.

Conclusion: In situations similar to ours, when inhaled desmopressin is at its lowest dose, we suggest changing the galenic form in order to reduce the bioavailability of the drug and thus make the adverse effect beneficial.