Control of jaundice in preterm newborns by an inhibitor of bilirubin production: studies with tin-mesoporphyrin.

Background: Studies in vitro, in animal models, and in adult and newborn humans have demonstrated that certain tin(Sn)-porphyrins that competitively inhibit the activity of heme oxygenase, the rate-limiting enzyme in heme catabolism, reduce production of bilirubin and can thereby substantially diminish plasma levels of the bile pigment.

Objectives: To assess the effectiveness of increasing doses of the heme oxygenase inhibitor, Sn-mesoporphyrin (SnMP), in moderating the development of significant hyperbilirubinemia and thus the requirements for phototherapy in preterm newborns.

Methods: In five randomized, blinded, placebo-controlled trials, SnMP in increasing doses from 1 mumol to 6 mumol/kg body weight was administered intramuscularly in the first 24 hours of life in preterm newborns of 210 to 251 days gestational age.

Alpha-fetoprotein in congenital hypothyroidism.

alpha-Fetoprotein (alpha-FP) was measured in dried blood spots from normal, congenital hypothyroid (CH) and transient hyperthyrotropinemic (TH) newborns as well as in serum from CH and TH babies together with thyroxine, triiodothyronine and thyrotropin. The half-life of alpha-FP had a median value of 12 days in the CH cases and 4.9 days in the TH cases.

Sn-protoporphyrin use in the management of hyperbilirubinemia in term newborns with direct Coombs-positive ABO incompatibility.

In two separate studies, in which two different treatment regimens of Sn-protoporphyrin were used, a total of 69 control and 53 treated infants were studied to determine whether this potent inhibitor of the enzyme, heme oxygenase, could ameliorate the severity of the hyperbilirubinemia which develops in term babies with direct Coombs-positive ABO incompatibility. The results indicate that Sn-protoporphyrin can, in appropriate doses, moderate the postnatal rate of increase of plasma bilirubin levels and diminish the intensity of hyperbilirubinemia in treated babies. In addition, a decreased use of phototherapy in Sn-protoporphyrin-treated infants was observed.

Effectiveness and safety of prenatal phenobarbital for the prevention of neonatal jaundice.

The effect of 100 mg of phenobarbital (PB) at bedtime for the last few wk of pregnancy on the incidence and severity of neonatal hyperbilirubinemia was studied. No effect was observed in the newborns of mothers who took less than ten tablets. In the 1310 newborns of adequately treated mothers (PB greater than or equal to 1.