Prescribing budgets could come under pressure as a result of European Commission proposals to let drug companies provide information directly to patients.
The commission has drawn up a consultation document that suggests standardising information that is available to patients across member states.
Drug companies would be allowed more freedom to provide information on prescription drugs directly to consumers than is currently the case in the UK, although comparisons between products and drug advertising would still be banned.
But UK bodies have warned that in practice, such steps could undermine the advertising ban. The NHS's European office said in its submission to the consultation: "It would be difficult in practice to distinguish between 'advertising' and 'pushed' [unsolicited] information... 'pushed' information should be prohibited, or if allowed, be subject to very strict oversight by national regulators."
The Picker Institute warned: "The pharmaceutical industry may wish to provide information to patients in order to influence the dialogue between clinicians and patients, increasing demand for new products and for established brands."
Picker Institute chief executive Angela Coulter told HSJ: "If this proposal is enacted, demand would be distorted and resources diverted from those who really need them."
The Royal College of GPs said in its submission that the proposal risked placing health professionals under "even higher pressure" and undermining efforts to control use of some drugs. "Patients may pressure their doctor to prescribe medicines about which they have received information from a pharmaceutical company, even if it is not in their best interests," it said.
Sue Carter, area head of prescribing and pharmacy at West Sussex primary care trust and NHS Alliance pharmacy and prescribing lead, said drug companies would be likely to devote less time to producing information for cheaper generic drugs. She said: "I would be very concerned about the effect [of the proposals] on patient safety and effectiveness of prescribing, as well as the impact on budgets." She said patient choice would be "distorted", as drug information would not be balanced.
A spokeswoman for the Association of the British Pharmaceutical Industry said that while it believed firms should be allowed to make information available to patients who requested it, it had never called for the right to provide unsolicited information.
The commission will draw up its legal proposals after analysing responses to the consultation, which closed on 7 April.