Among this group, mothers were found to have consumed, on average, almost 60 percent more codeine than mothers with healthy babies. This led the team to conclude, in fact, that excessive codeine consumption while breast-feeding can compromise a baby's health, whether or not the mother is one of the relatively few affected by a genetic predisposition to overproduce morphine.
But when honing in on the genetic front, the researchers indeed found that two mothers of symptomatic children carried the problematic genetic predisposition. In these two instances, the child's reaction to codeine consumption was particularly severe, with one baby ultimately dying as a result.
Julie Kable, an assistant professor of pediatrics at Emory University School of Medicine in Atlanta, said that the work represents "the wave of the future in science.
"The basic nature of this finding does not surprise me, given that this is where science is going, with a huge effort being made to better understand the interaction of one's genes with exposure to various substances. And it's not unheard of for this kind of science to lead to an altering of ob/gyn practice. It should be said, for example, that it wasn't so long ago -- in the 60s and 70s -- that women were actually given alcohol to stop premature labor. So, the possibility that this is true does create a burden to do the appropriate testing before we make such prescriptions."
For more on codeine consumption and breast-feeding, visit the U.S. Food and Drug Administration.
SOURCES: Parvaz Madadi, Ph.D. candidate, department of physiology and pharmacology, University of Western Ontario, London, Ontario, Canada; Julie Kable, Ph.D., assistant professor, pediatrics, Emory University School of Medicine, Atlanta; Aug. 20, 2008, Clinical Pharmacology & Therapeutics, online