U.S. Supreme Court justices sharply questioned on Tuesday whether a state may prohibit the use of prescription drug records for marketing, expressing concerns that it violated free-speech rights.

Chief Justice John Roberts said Vermont in adopting the law wanted to lower healthcare costs not by direct regulation, but by restricting the flow of information and "censoring" what doctors can hear from pharmaceutical companies so they prescribe generic drugs. A number of other justices voiced similar concerns in hearing arguments about the law that restricts commercial use of prescription records.

Pharmaceutical manufacturers use data about a doctor's prescribing habits to better inform their drug salespeople when they visit physician offices to market certain products.

The court seemed sympathetic to the arguments by attorney Tom Goldstein in challenging the law on behalf of three data mining companies - IMS Health, Verispan and Source Healthcare Analytics, a unit of Dutch publisher Wolters Kluwer - that collect and sell such information.

Goldstein said the law discriminated against drug companies and made it harder for them to get their message to doctors while unfairly favoring views espoused by the state and insurance companies that favor generic drugs.

"What the state doesn't get to do is just pick sides and prevent the debate from happening," he said, adding that Vermont went too far and violated free-speech protections.

Vermont, Maine and New Hampshire have been the only states to adopt such laws, though similar measures have been proposed in the last three years in about 25 states across the country.

Medical Privacy At Issue
Vermont Assistant Attorney General Bridget Asay defended the law. She said the confidential medical data at issue was like "inside information" and the law sought to protect doctor privacy. But Justice Antonin Scalia suggested another way for a doctor to avoid unwanted marketing pitches from a drug company representative. "He can do that by saying: I don't want to talk to you."

Justice Ruth Bader Ginsburg said the law seemed to be intended to promote sales of generic over brand-name drugs.

"Why doesn't that run up against what this court has said that you can't lower the decibel level of one speaker so that another speaker, in this case the generics, can be heard better?" she asked Asay.

Vermont pharmacies must collect prescription drug information.

The law bars pharmacies from disclosing the data and gives prescribing doctors the right to consent before any information is sold or used in marketing.

Companies that collect the data have said the information about doctors' prescribing patterns can be used to help monitor safety issues of new medications, reduce costs and for research purposes like studying treatment outcomes. The Obama administration supported Vermont. A government attorney said the narrowly written law enabled a physician to determine whether drug-prescribing records can be used for marketing.

A ruling is expected by the end of June.