Hyponatraemic coma induced by desmopressin and ibuprofen in a woman with von Willebrand's disease.

A middle-aged woman was admitted to the hospital after being found unconscious at home. A brain CT scan excluded an intracranial bleed or other focal abnormality. Laboratory analysis showed hyponatraemia (sodium: 121 mmol L(-1)) and a low plasma osmolality, with normal sodium excretion and urine osmolality. A diagnosis of hyponatraemic coma was made. The patient was treated with water restriction; 24 h later the sodium was 135 mmol L(-1) and the patient was neurologically fully recovered. The patient, who suffered from von Willebrand's disease, had received desmopressin and ibuprofen for analgesia 2 days before after a dental intervention. She had received desmopressin several times in the past without any complications. A few patients treated with desmopressin for coagulation abnormalities have been reported to develop water intoxication and severe hyponatraemia resulting in seizures and coma. By inhibiting prostaglandin synthesis, non-steroid anti-inflammatory agents (NSAIDs) potentiate the effect of water reabsorption in the renal tubules of vasopressin, therefore enhancing water retention. Desmopressin and NSAIDs should not be used in combination in patients with bleeding disorders, but it is often followed in clinical practice. In addition, this is probably not an unusual situation in patients treated with desmopressin for other 'non-haemorrhagic' indications. This report emphasizes the need for practitioners to be aware of this rare but severe complication.