Observations THE WEEK IN MEDICINE

Is killing the pain worth the risk?

BMJ 2007; 334 doi: https://doi.org/10.1136/bmj.39104.415961.68 (Published 25 January 2007) Cite this as: BMJ 2007;334:186
  1. Rebecca Coombes, journalist, London (rcoombes{at}bmjgroup.com)

    MPs argue that the regulators went too far when it banned co-proxamol

    The story so far

    MPs staged a last ditch attempt to get an effective ban on the painkiller co-proxamol overturned last week. The bid was ultimately thwarted but it gave a valuable insight into how patients and doctors are handling the phased withdrawal of the once popular analgesic two years after the uncompromising decision was made.

    Co-proxamol is a prescription only analgesic that combines paracetamol (325 mg) and dextropropoxyphene (32.5 mg). It has low side effects and is popular with patients with chronic pain. But it is also the second most frequent means of suicide with prescribed drugs in England and Wales, second only to tricyclic antidepressants. Concern about the number of such deaths was expressed in the BMJ as long ago as 1980.

    In 2004 the Medicines and Healthcare products Regulatory Agency announced a phased withdrawal of the painkiller. A review by the agency found that around 300-400 people a year die as a result of taking too many tablets either deliberately or by mistake. That co-proxamol is potentially very toxic was highlighted in a 2005 study in the British Journal of Clinical Pharmacology. It found that an overdose of co-proxamol was more than 10 times more likely to be fatal than one of co-dydramol or co-codamol.

    The BNF in 2006 rated co-proxamol as having little more analgesic effect than paracetamol alone, but was more hazardous. “An important disadvantage of co-proxamol is that overdosage is complicated by respiratory depression and acute heart failure due to the dextropropoxyphene. Rapid treatment is essential,” it said.

    The drug will be available under prescription until the end of the year, after which unlicensed co-proxamol will be prescribed only on a named patient basis.

    General practitioners have been withdrawing co-proxamol since summer 2005—but despite the evidence backing the decision to ban, fans of the drug are still hoping to keep it on the market.

    A chance to reconsider

    In an adjournment debate at the House of Commons last week, Labour MPs Anne Begg and Howard Stoate urged the agency to reconsider. It should be possible to address the high incidence of suicide among those using co-proxamol, without a full ban, they argued.

    Begg, who has the genetic condition Gaucher's disease, was a co-proxamol user until her GP took her off the drug following the regulator's ruling. But attempts to find an alternative to co-proxamol have been unsuccessful, she told the Commons: “I was told that full strength paracetamol would be just as effective as an analgesic. That is simply not true. I have found alternatives, although paracetamol supplemented with dihydrocodeine is probably more powerful that co-proxamol.”

    Last summer there were problems with the supply of the drug, possibly because of confusion over its status, she reported. Her concern was that the supply of the drug would dry up for good—even for those on named patient status.

    Stoate, a former GP, said that of 72 000 patients who continue to use co-proxamol, there were some for whom no other drug would do. He quoted a GP, who is a prescribing lead in south London. “The problem is that every practice has a number of people who have no alternative analgesic. I'm aware of several patients who have tried everything else and nothing works.”

    A Norfolk GP said it was a valuable drug because of its low side effects. He told Stoate: “In 20 years of practice I have seen more side effects from co-dydramol and co-codamol and more lives wrecked by dihydrocodeine addiction.”

    Stoate also bolstered his argument with the words of the president of the British Society of Rheumatology, Andrew Bamji: “It is unreasonable to withdraw a drug from those who understand the risk.”

    There has been a huge drop in the number of prescriptions from 435 250 in January 2005 to just over 70 000 in August 2006. Only 1350 were new prescriptions.

    Begg said the decision to go ahead with a phased ban created huge confusion, and she quoted Pulse magazine. “It had the headline ‘GPs demand U-turn on co-proxamol ban.' Its own survey showed that 70% of GPs and 94% of rheumatologists demanded that MHRA revisit its decision,” she said.

    Instead of de-licencing co-proxamol, why not make it a controlled drug under schedule 3 of the Misuse of Drugs Act 1971, said MPs. Prescriptions would be initiated at specialist level, but GPs could make repeat prescriptions, and they could be restricted for chronic, rather than acute, pain.

    But according to health minister Caroline Flint, many of the drug related suicides associated with co-proxamol involved people that had not been prescribed them. She used the example of a troubled teenager, coming across the tablets in “granny's medicine cabinet.” Flint said only 367 letters had been received from concerned patients over the past two years.

    She estimated that 100 lives had already been saved from a phased withdrawal of the drug and warned that controlling it could see usage levels shoot back up.

    What next?

    The MHRA is offering doctors the opportunity to prescribe on a named patient basis what will, in effect, be an unlicensed drug after December 2007.

    The main manufacturer has confirmed to the Department of Health that it intends to continue producing co-proxamol following the cancellation of the licences at the end of 2007. “If there is clear clinical need, it will still be possible to prescribe co-proxamol, but in a more targeted way,” said Flint.

    But this won't be viable, says Stoate. “Few GPs, if any, will wish to expose themselves to the possible threat of litigation by doing so, however strong the patient's need for the drug. In practice, the solution amounts to a comprehensive ban.”

    Instead the agency should have the courage to trust GPs who are, “highly trained and well paid, to make decisions on a daily basis that require them to tread the fine line between therapeutic benefits and the disadvantages of drugs,” he said.

    One blogger (navabs.blogspot.com), Navabs, an investment banker from Essex, who has ankylosing spondylitis, said of the decision, “Where does it leave me? It keeps us normal. Why do I have to pay the price for suicidal people abusing a miracle drug? The [alternatives] lack the ‘kick' that co-proxamol has.”

    “I was told that full strength paracetamol would be just as effective an analgesic as co-proxamol. That is simply not true”

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