Severe water intoxication secondary to the concomitant intake of non-steroidal anti-inflammatory drugs and desmopressin: a case report and review of the literature.

Most of the clinical data on the safety profile of desmopressin (DDAVP), which is an effective treatment for both polyuric conditions and bleeding disorders, originate from studies on the tailoring of drug treatment, whereas few reports exist describing severe side effects secondary to drug-drug interaction. We herein describe a case of severe hyponatremia complicated by seizure and coma due to the intake of non-steroidal anti-inflammatory drugs (NSAIDs) in a patient on DDAVP replacement therapy for central diabetes insipidus (DI). A 50-yr-old Caucasian man, with congenital central DI, developed an episode of generalized tonic-clonic seizure, resulting in coma immediately after being admitted to the Emergency Unit for weakness and emesis. Based on his medical history and clinical findings, water intoxication secondary to ketoprofen intake (200 mg/day for the last 3 days) concomitant with DDAVP replacement therapy (Minirin(®) 60 mcg 4 tablets a day) was hypothesized as being the cause of the severe euvolemic hypotonic hyponatremia (natremia 113 mEq/l, plasma osmolality 238 mOsm/Kg). After standard emergency procedures, appropriate gradual restoration of serum sodium levels to the normal range was achieved in 72 hours. Hydratation was maintained according to water excretion and desmopressin therapy was re-introduced. We discuss this case report in the context of the published literature. The present report first highlights the potentially life-threatening side effects associated with over-the-counter NSAIDs during DDAVP replacement therapy for central DI. Risks and benefits of co-treatment should be carefully considered and therapeutic alternatives to NSAIDs should be recommended to patients with central DI in order to improve DDAVP safety.

Is the 250 µg ACTH test a useful tool for the diagnosis of central hypoadrenalism in adult patients with pituitary disorders?

OBJECTIVE: The diagnosis of hypothalamic-pituitary-adrenal insufficiency (HPAI) is a major clinical challenge. The gold standard procedure remains insulin tolerance test (ITT). This study aimed to evaluate the usefulness of standard-dose corticotrophin stimulation test (SDCT) in diagnosing HPAI. DESIGN: In this prospective study we performed SDCT and ITT in 55 consecutive patients (37F/18M) affected by pituitary disorders. RESULTS: A normal response to ITT was found in 44 patients, while HPAI was diagnosed in 11. Using ITT as reference test, the ROC curve showed that a cortisol value of 18 µg/dl (500 nmol/L) at 30 min or 21.8 µg/dl (600 nmol/L) at 60 min after SDCT represents the best compromise between sensitivity and specificity in diagnosing HPAI. Moreover, 30 min cortisol values >20.3 µg/dl (560 nmol/L) or 60 min cortisol values >24.1 µg/dl (665 nmol/L) exclude HPAI. Four out of 15 patients of Group A, previously non-respondent to SDCT, showed a normal response to a second SDCT. CONCLUSIONS: SDCT is not a reliable tool to identify HPAI, but it appears to be more useful in confirming the normality of HPA function. When SDCT fails to exclude HPAI, ITT should be performed. If ITT is contraindicated, retesting patients by SDCT is useful before starting an unnecessary replacement therapy.