Generic And Branded Thyroid Drugs "Equal"

Patients being treated for hypothyroidism obtain similar therapeuticoutcomes whether they receive branded thyroid drugs or their generic counterparts, according to a report in The Journal of the American Medical Association (April 16 issue). This study has been suppressed for seven years and has only been published after Knoll Pharmaceutical, the manufacturer of Synthroid (levothyroxine), which dominates the $600 million market in the USA, agreed not to sue the study's authors, Betty Dong et al of the University of California Medical Center, reports the Wall Street Journal.

The study concluded that two brand-name levothyroxine products, Synthroid and Levoxyl (a cheaper brand name product similar in price to generic forms), are bioequivalent to two generic levothyroxine products and "are interchangeable without loss of therapeutic efficacy in the majority of patients for treatment of hypothyroidism." The authors estimated that if generic drugs or Levoxyl were prescribed instead of Synthroid, annual savings in the USA could amount to $356 million.

Drummond Rennie, deputy editor of the JAMA, explains that "in 1987, to establish that Synthroid was truly more effective than competing preparations, Flint Laboratories, then manufacturer of Synthroid, approached Betty Dong at UCSF....Flint and Dong signed a lengthy protocol/contract to finance comparative studies of the bioequivalence of Synthroid and three other preparations, and both sides expected the study to show that Synthroid was superior."