In addition, packs containing more than 32 tablets of effervescent codeine will now only be available on prescription.
The changes form part of a package of measures announced by the MHRA to tackle risks arising from the fact that medicines containing codeine and dihydrocodeine may be addictive.
Medicines packs will now include clear and prominently positioned warnings about the risk of addiction, and the importance of not taking these medicines for longer than three days.
There will also be updated controls on advertising to ensure the new warnings are clearly presented, the MHRA has said.
The MHRA's director of vigilance and risk management of medicines, Dr June Raine, stressed that, taken in the correct manner and for the right purposes, codeine and dihydrocodeine are effective and acceptably safe medicines. ‘However,' she said, ‘these products can be addictive and we are taking action to tackle this risk'.