Ritalin - Linked To Chromosome Abnormalities

March 5, 2005

http://www.newswise.com/articles/view/510069/

Newswise — In a small but startling preliminary new study, Texas researchers have found that after just three months, every one of a dozen children treated for attention deficit/hyperactivity disorder (ADHD) with the drug methylphenidate experienced a threefold increase in levels of chromosome abnormalities—occurrences associated with increased risks of cancer and other adverse health effects.

The researchers say that to their knowledge this is the first study addressing the potential chromosome-breaking effects associated with treatment of children with methylphenidate, the generic name for a group of drugs that includes Ritalin, Concerta, Metadate CD and others.

Methylphenidate is the most widely prescribed of a class of amphetamine-like drugs used to treat ADHD, with more than 10 million prescriptions written for it in 1996 alone. Between 1991 and 1999, United States sales of methylphenidate increased more than 500 percent.

Researchers at The University of Texas M.D. Anderson Cancer Center in Houston and the University of Texas Medical Branch at Galveston (UTMB) reported their detection of the chromosome abnormalities in the journal Cancer Letters. Their peer-reviewed paper is to be published several months hence, but the journal editors have made it available online in the journal’s “articles in press” section.

The authors said they undertook the study because, even though methylphenidate has been approved for human use for more than 50 years, “there are surprisingly few studies” in either animals or human beings “on the potential for serious side effects,” such as causing mutations and cancer. In 1996, a report discussing several two-year-long animal studies showed that the highest levels of methylphenidate tested caused liver tumors in male and female mice. However, similar studies in rats showed no such tumors