Last year eight million prescriptions were issued in England and Wales for co-proxamol - often for backpain or mild arthritis. The patent has expired, so it is a generic product.
The Medicines and Healthcare products Regulatory Agency (MHRA) has decided it should be taken off the market. It's involved in 300-400 deaths a year, a fifth of which are accidental overdoses.
So does this affect any brands?
Eli Lilly produces Distalgesic through its subsidiary Dista but the firm's spokesman did not return calls as PRWeek went to press. Other brand names are Cosalgesic and Dolgesic.
Does the co-proxamol decision leave a gap in the market?
Many pharma companies have painkilling brands that could benefit from the withdrawal. But over the past few years there have been conscious efforts to reduce access to painkillers - seen as an important step towards preventing suicide - which is why, for example, you can only buy paracetamol in packs of 16 in supermarkets.
Why has co-proxamol suddenly become dangerous?
It hasn't. MHRA chairman Alasdair Breckenridge said that the risks attached to co-proxamol have long been known by doctors. But taking it off the market is a signal that measures to strengthen the labelling of the drug have been 'ineffective in reducing the high fatality rate involving both intentional and accidental overdose'. Co-proxamol is a combination of paracetamol and dextropropoxyphene (DXP) - yet the risk of overdose is higher than with paracetamol alone.
Is withdrawal of a drug unusual?
No. Merck & Co's anti-arthritis drug Vioxx, which contributed to risk of heart attack and stroke, was a high-profile withdrawal last year.
What's the timescale this time?
Co-proxamol will be phased out over 18 months, although patients taking it are not advised to stop until they've seen their doctor.
Further information www.mhra.gov.uk.