GPs should be the first port of call for patients who have suspicions about the authenticity of their medicines, the MHRA believes.
Nimo Ahmed, head of intelligence at the agency's enforcement group, told GP that the MHRA was working on guidance for doctors on counterfeit medicines.
The guidance that will be issued in the next few months will, he said, highlight the role of GPs in dealing with patients' concerns about possible counterfeit medicines.
'If patients have any suspicions about a medicine, whether it has been bought online or is from a high street pharmacy, in the first instance their GP or pharmacist should be patients' first port of call,' he said.
However, GPC prescribing lead Dr Bill Beeby said he thought there was a clear difference between GPs' responsibilities for drugs bought online and those for medicines obtained through a conventional routes.
'If patients are buying things online, I'm not going to give them a professional opinion about it,' he said. 'I can't see that any GP is going to be happy about doing that. If people have obtained medicines through a non-conventional system, it's clearly more risky - you get what you pay for.'
However, he said he recognised that patients may be concerned about changes to medicines that have come through the legitimate supply chain.
'I as the prescriber and the pharmacist as the dispenser have a clear responsibility to ensure that medicine is legitimate and safe,' he said.
'But there is a very clear distinction between medicines that GPs do have a responsibility for and those bought online, where most GPs would be wise not to give an opinion.'
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