A case of severe diazoxide toxicity

Summary Hyperinsulism is a rare cause of persistent hypoglycemia in the neonatal period. Therapy can be accomplished either surgically or pharmacologically. Diazoxide treatment remains the mainstay of medical therapy. Tolerance of diazoxide is usually excellent, but several adverse effects of this drug have been described. A case of severe diazoxide intoxication with fluid retention, congestive heart failure, and respiratory failure is reported. The patient was a 43-day-old infant, affected by persistent and severe hypoglycemia. After the diagnosis, hyperinsulinism was established he was treated with diazoxide (17 mg·kg−1 daily) and octreotide (12 μg·kg−1 daily). A few days later he presented with hepatomegaly, severe fluid retention, diffuse edema, congestive heart failure, and respiratory failure requiring mechanical ventilation. After introduction of ACE inhibitors he developed acute renal failure. The clinical condition worsened and he developed pulmonary hypertension requiring high-frequency oscillatory ventilation. Diazoxide was stopped on the 12th day in spite of poor control of blood sugar. During the next 5 days his hemodynamic status dramatically improved and he was weaned from catecholamines: he lost weight, had a negative fluid balance, and the edema disappeared, a normal diuresis resumed and renal function improved. Improvement of respiratory patterns and gas exchange made it possible to switch back to conventional ventilation and then to extubate the patient. Echocardiography demonstrated reduction of the PA pressure to normal and resolution of atrial enlargement. The patient was scheduled for elective subtotal pancreatectomy. Diagnosis and management of diazoxide intoxication are discussed.