On April 22, 1965, the second meeting of an Ad Hoc Advisory Committee on the Teratogenic Effect of Certain Drugs was held under the auspices of the Food and Drug Administration in order to review available data related to the teratogenic effect of meclizine, cyclizine, and chlorcyclizine and to make recommendations regarding the dispensing status and labeling directions of drug articles containing the subject compounds. On July 27, 1965, the recommendations resulting from that meeting were transmitted to the medical director of the FDA by the chairman of the committee. (A list of the members appears at the end of this paper.) The present communication offers a summary of the scientific and clinical background considerations upon which the recommendations of the committee were based, and final decisions of the FDA in the matter.
In the latter part of 1962, attention was drawn to the possibility of human fetal