I am forwarding this letter from Dr. Samuel Epstein, written in April, 2001, about the evidence of cancer risks for children taking ritalin.. I am looking for more research on the subject. I hope to find that someone, obviously not the FDA, has done more research.
“Reading, Writing and Ritalin” TV Program Overlooks Evidence on Cancer Risks in Children
Chicago, 4/10/01 — Bill Kurtis is to be warmly commended for his Arts & Entertainment (A & E) balanced and informative 4/9/01 TV program on the abuse and misuse of Ritalin for the treatment of children with “Attention Deficit Hyperactivity Disorders” (ADHD). As Kurtis noted, the U.S. uses some 90% of the world’s supply of Ritalin, now overprescribed to up to 6% of elementary and pre-teen school children for a “grab bag” of behavioral disorders. However, no mention was made of the substantive evidence on the drug’s cancer risks of which parents, teachers and school nurses still remain uninformed and unaware.
Some 40 years after the drug had been marketed by Ciba Geigy, carcinogenicity tests were conducted by the National Toxicology Program, at the taxpayers expense, the results of which became available in 1993. Adult mice were fed with the drug over a two-year period at dosages close to those prescribed to children. The mice developed a statistically significant incidence of liver abnormalities, liver tumors and very rare highly aggressive cancers known as hepatoblastomas. These findings are all the more disturbing as the tests were conducted on adult, rather than young mice which would be expected to be much more sensitive to carcinogenic effects. The National Toxicology Program concluded that Ritalin is a “possible human carcinogen”, and recommended the need for further research.
The Food and Drug Administration’s minimal response to this alarming information was to send a “Dear Doctors” letter warning of “a weak signal of carcinogenic potential”, coupled with assurances, in which industry joined, that the drug was safe. At the same time, the FDA also promised to initiate follow-up animal tests and human studies, although these have yet to be undertaken. The current Physicians’ Desk Reference (PDR) manual admits the evidence on the carcinogenicity of Ritalin, now manufactured by Novartis, qualified by the statement that “the significance of these results is unknown”, apparently not recognizing that this is more alarming than reassuring. Apart from cancer risks, the drug has also been shown to induce genetic damage in human cells in test tube studies, and also in preliminary studies on treated children.
Concerns on cancer risks from Ritalin are all the more acute in view of the escalating incidence of childhood cancer, by over 30% over the last few decades, quite apart from delayed risks of cancer in adult life.
The use of Ritalin should be sharply restricted and then only prescribed by highly- qualified psychiatric specialists, and also only after the parents have been explicitly informed of the drug’s cancer risks. There is a strong body of expert opinion that the majority of “ADHD” children can be safely and effectively treated, although at greater expense, by procedures including behavior modification and biofeedback.
Contact: Samuel S. Epstein, M.D., emeritus professor of environmental and occupational Medicine, University of Illinois School of Public Health, Chicago, and Chairman, Cancer Prevention Coalition; phone 312-996-2297; fax 312-996-1374; email firstname.lastname@example.org