Background: Dextromethorphan (DM), the d-isomer of the
codeine analog levorphanol, is an active ingredient present in a
variety of cough and cold remedies. Recently, data generated from a
study in chick embryos were extrapolated to suggest that pregnant women
should not use this drug because of the risk of birth defects. We
conducted a controlled study of pregnant women who used DM, to examine
the possible teratogenic risk in humans.
methods: We followed up women who used DM and had been counseled
by the Motherisk Program during their pregnancy. A control group of
women was matched for age, smoking, alcohol use, and disease state
(upper respiratory tract infection, not treated with DM).
Results: We were able to ascertain pregnancy outcome
in 184 women. There were 172 live births, 10 spontaneous abortions, 1
therapeutic abortion, and 1 stillbirth. One hundred twenty-eight of the
women used the drug during the first trimester of pregnancy. There were
three major malformations (2.3%) among the babies of women who used DM
in the first trimester, seven minor malformations, and the mean
(± SD) birth weight was 3,381 ± 670 g. In the control
group, there were 174 live births, 8 spontaneous abortions, and 2
therapeutic abortions. There were five major malformations, one of
which was a chromosomal abnormality (2.8%), eight minor malformations,
and the mean birth weight was 3,446 ± 571 g.
Conclusion: This study fails to show that DM use during
pregnancy increases the rates of major malformations above the expected
baseline rate of 1% to 3%.