Buprenorphine metabolism by preterm placentas: A pilot study

Abstract

The focus of this investigation is to attempt to identify and characterize the major enzyme responsible for metabolism of buprenorphine to nor-buprenorphine in human preterm placentas and to elucidate whether the development/gestational age of the placenta affects metabolism of buprenorphine. The estimated apparent Km did not appear to change with gestational age suggesting the affinity of buprenorphine does not change throughout gestation. On the other hand, the estimated Vmax did appear to increase with gestational age suggesting the activity increases with gestational age. Our attempt to identify the enzyme responsible for metabolism in earlier gestational age placentas revealed that CYP19 remains the major metabolizing enzyme of buprenorphine but suggests additional enzymes may be involved, namely, CYP3A4, 1A1, 2E1, 2D6 and 2C19. Further studies must be conducted for conclusions to be drawn but we hope this report can contribute to the design of future studies on preterm placental metabolism of drugs.