Dr Jim Kennedy, RCGP prescribing spokesman and a member of the expert panel advising the NAO, branded the presentation of Prescribing Costs in Primary Care 'poorly informed and simplistic'.
He said he was concerned about comments that suggested 'inefficiencies, waste or the susceptibility of prescribers to pharmaceutical industry marketing'.
Far from being careless with the public purse, GPs are 'among the most sophisticated prescribers in the world and uniquely efficient at individualising therapy', Dr Kennedy said.
Dr Mark Spencer, a west London GP who also sat on the expert panel, called the presentation 'bizarre' and said it bore little resemblance to the report.
Last week the NAO said that GPs in England wasted £227 million a year on unnecessary or inappropriate prescriptions.
Patients themselves wasted a further £100 million by ordering and hoarding unneeded drugs.
Sir John Bourn, NAO head, said that cash to treat more patients would be released 'if GPs more often followed official guidelines and prescribed generic and other cheaper drugs where suitable'.
Edward Leigh MP, chairman of the Public Accounts Committee, added that 'GPs need to be less influenced by the blandishments of the drugs industry'.
But Dr Kennedy said that UK GPs were 'the most informed and savvy' in the world. 'The pharmaceutical industry uses the UK as its training ground, the same way the SAS trains in the Cairngorms,' he said.
The NAO called on PCTs to improve against other PCTs, to identify 'outlier' practices and to implement incentive schemes to change GPs' prescribing habits.
But the report admitted that, at 83 per cent, UK generic prescribing rates were among the highest in Europe.
Dr Kennedy said the sums wasted represented a fraction of the £8.2 billion drugs budget.
Professor Mayur Lakhani, RCGP chairman, called on PCTs to provide 'more face-to-face prescribing support from credible advisers'.
The NAO concluded that GPs could save £200 million by prescribing more efficiently after examining prescribing of statins, ACE-inhibitors or angiotensin-II receptor antagonists, proton pump inhibitors and clopidogrel.
But Dr Kennedy said the extrapolations used by the NAO were 'riddled with problems'.What do you think? Comment below or email us at GPletters@haymarket.com
GENERIC SCRIPS - 83%: The UK generic prescribing rate is among the highest in Europe.