Including product risk information on Internet search ads, as required by warning letters sent this month by the US Food and Drug Administration (FDA) to 14 drug majors, has made the ads even more misleading, say the firms.

In early April, the FDA issued the warning letters after routine surveillance by its Division of Drug Marketing, Advertising & Communications (DDMAC) found that Internet company-sponsored links on search engines such as Google had “made representations and/or suggestions for the efficacy” of a total of 48 drugs without communicating any risk information about them, thus misleading patients. Among the medicines were 19 which carry “black box” warnings of serious side effects, and some of the ads included information on uses of the drugs which have not been approved by the FDA.

The firms set about removing the ads and revising them as soon as they received the warning letters, but they have since discovered that it is impossible to include all the required risk information in the 95 characters which are available for such ads, and that trying to do so only makes them more confusing and misleading, according to a report in the New York Times.

Moreover, companies which have tried to avoid the FDA risk disclosure rule by introducing a generic-sounding web address - referring to the condition or type of treatment without naming the brand - to redirect consumers to the brand’s website have found that this also risks confusion, as users may believe they are being directed to an independent information source rather than a sales site, the report adds.

Commenting on the agency’s actions, leading law expert Arnold Friede criticised DDMAC for violating “cardinal principles of advertising interpretation that the FDA itself has routinely adopted.”

“The whole purpose of a sponsored link is to persuade the information seeker to click on the link,” and, before receiving the warning letters, the companies had assumed that the “one-click rule” applied, says Mr Friede, a member of the health law department at Washington law firm McDermott Will & Emery. Moreover, in comments reported on the firm’s website, he warns: “if sponsored links were to disappear because of the position being taken by the FDA, “then the information seeker will be relegated to wading through a list of web sites, most of which are not even regulated by FDA and which contain all manner of information whose validity is largely unknown."

Drugmakers and advertisers are now calling on the agency for a new set of standards which specifically address Internet search ads, or at least for clear guidelines, rather than requiring them to try to adhere to rules which were originally developed for television and magazines.