Nephrocalcinosis complicating medical treatment of posthemorrhagic hydrocephalus.

Furosemide and acetazolamide are often used concurrently to treat posthemorrhagic hydrocephalus in premature infants with intraventricular hemorrhage. Eleven premature infants with posthemorrhagic hydrocephalus were monitored for the development of hypercalciuria during treatment using urine calcium/creatinine (Ca/Cr) ratios (normal: less than or equal to 0.21). Seven of 11 infants (64%) developed hypercalciuria; 5 of those 7 infants had nephrocalcinosis on renal ultrasonography. Infants who developed nephrocalcinosis had urine Ca/Cr ratios of 0.5-4.0. In all 5 infants with nephrocalcinosis, renal calculi decreased and urine Ca/Cr improved after drug therapy was discontinued. The combined use of acetazolamide and furosemide as therapy for posthemorrhagic hydrocephalus places premature infants at high risk for nephrocalcinosis. It is suggested that urine Ca/Cr be monitored closely in infants receiving these drugs and that other treatment modalities be considered when the urine Ca/Cr ratio exceeds 0.21.