NTP-CERHR monograph on the potential human reproductive and developmental effects of methylphenidate

The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for methylphenidate to cause adverse effects on reproduction and development in humans. Methylphenidate was selected for evaluation because of 1) widespread usage in children, 2) availability of developmental studies in children and experimental animals, and 3) public concern about the effect of this stimulant on child development. Methylphenidate is a central nervous system stimulant approved by the U.S. Food and Drug Administration for the treatment of attention deficit hyperactivity disorder (ADHD) in persons 6 years of age and older and for narcolepsy. The results of this evaluation on methylphenidate are published in an NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of Methylphenidate, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to methylphenidate on human development and reproduction. First, there is negligible concern for methylphenidate-induced tics and movement disorders. This conclusion is based on studies showing that children treated with therapeutic doses of methylphenidate have no evidence of movement disorders or tics due to the medication. Second, there is minimal concern for methylphenidate-induced growth restriction. This conclusion is based on growth restriction being observed in animal studies only at high doses of methylphenidate using a non-therapeutic route of exposure. The effect on growth was reversible. Finally, there are insufficient data to draw conclusions on 1) an association between methylphenidate therapy in pregnant women and pregnancy loss and 2) possible reproductive effects of methylphenidate in humans. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available in electronic PDF format on the CERHR web site http://cerhr.niehs.nih.gov/ and in printed text or CD-ROM from the CERHR.