CHICAGO: The ethics of the Zeneca case looked even more problematic following news that the maker of a pricey synthetic thyroid hormone suppressed research findings that cheaper alternatives are just as effective in controlling thyroid-related illnesses. A story in Wednesday's issue of the Journal of the American Medical Association said the Knoll Pharmaceutical Company attempted to discredit and keep from public view a University of California study that found Synthroid, the firm's flagship thyroid medication, no more effective than the generic competition. Although Synthroid's prior manufacturer, Flint Laboratories, commissioned the study, Knoll reportedly threatened author Betty Dong with legal action after she tried to publish it in 1995. The company denied engaging in intimidation and said the study should not be published because it contained numerous flaws. "It did not meet the requirements of a valid study, which include the proper selection of patients, appropriate testing methods and control of drug dosage," the company said in a statement. Synthroid controls about 85 percent of the $600 million market for synthetic thyroid medications, which are used to help people whose thyroid glands are damaged by disease or removed by surgery. But estimates showing Americans could save up to $356 million a year by using generic brands may reduce the company’s share of the market.