Reversal of chronic diabetes insipidus during treatment with protriptyline

We have described a 13-year-old white boy with Ondine's curse, sleep apnea and cataplexy who simultaneously developed progressive hypothalamic neuroendocrine deficiencies requiring replacement therapy. The patient was treated with protriptyline, a nonsedating tricyclic antidepressant, for control of the sleep-related symptoms. An unexpected result was the apparent reversal of his chronic diabetes insipidus by protriptyline, necessitating discontinuation of lysine-vasopressin. Some possible mechanisms of action were discussed.