GPs will be able to endorse any prescription to opt it out of the arrangements. But this drug substitution system will not be able to take account of cases where branded drugs are cheaper than generic versions, the DoH has acknowledged.

The list forms part of the government's proposal for how generic substitution will be introduced in England - the proposal is open for comments until 30 March.

Click here for the full list of products

The list includes products for which there is a high level of branded prescribing and a large difference between brand and generic prices.

GPC prescribing lead Dr Bill Beeby said that although generic prescribing would save some money, it would have costs in terms of doctors' and pharmacists' time.

'The better answer would be to make sure people are prescribing generically,' he said.

Practices with low generic prescribing rates can be identified, he said. 'Work can then be done to increase their generic prescribing. That is professional activity that should be supported.'

Around 5 per cent of prescriptions are for branded products for which a generic equivalent is available. The government believes that for around half of these a generic product would be clinically appropriate. But Dr Beeby said this figure was a 'guestimate'.

Introduction of generic substitution will involve changes to NHS arrangements and devolved administrations will determine their own plans.

The Scottish government said it would be consulting 'shortly' on its plans. Substitution schemes are already being piloted in Northern Ireland.

There had originally been no plan for formal consultation or parliamentary debate on plans to allow pharmacists to substitute drugs prescribed by brand with generic replacements.

However, GPs and charities expressed concern that the changes would affect patient care and the government agreed last August to consult on its proposals.