Clinical trial of tin mesoporphyrin to prevent neonatal hyperbilirubinemia.

Abstract

To assess the efficacy of the heme oxygenase inhibitor, tin mesoporphyrin (SnMP), to reduce total bilirubin (TB) levels. Masked, SnMP (4.5 mg kg(-1)), placebo-controlled, multicenter trial of single intramuscular injection to newborns ⩾35 weeks gestational age whose predischarge screening transcutaneous bilirubin (TcB) was >75th percentile. Two hundred and thirteen newborns (median age 30 h) were randomized to treatment with SnMP (n=87) or 'sham' (n=89). We found that the duration of phototherapy was halved. Within 12 h of SnMP administration, the natural TB trajectory was reversed. At age 3 to 5 days, TB in the SnMP-treated group was +8% but sixfold lower than the 47% increase in the sham-treated group (P<0.001). At age 7 to 10 days, mean TB declined 18% (P<0.001) compared with a 7.1% increase among controls. No short-term adverse events from SnMP treatment were noted other than photoreactivity due to inadvertent exposure to white light phototherapy. Early, predischarge SnMP administration decreased the duration of phototherapy, reversed TB trajectory and reduced the severity of subsequent hyperbilirubinemia.