Cough Syrup Study Raises Concerns

A key ingredient in cough syrups and such tablets as Robitussin, Nyquil and Tylenol Cold caused severe defects in chicken embryos and should be avoided by pregnant women, researchers warned. However, other studies have shown no link between dextromethorphan and birth defects in humans, and experts said more study is needed. Dextromethorphan stops coughing by blocking a receptor of the central nervous system. However, in embryos it knocked out the receptor, causing the defects, said the study’s leader, Thomas H. Rosenquist of the University of Nebraska Medical Center.