GPs have been given conflicting advice on prescribing paracetamol in patients with osteoarthritis, after Scottish medicines experts recommended low doses of the drug could be considered as a first-line option, in direct opposition to recent recommendations from NICE.
The new recommendation comes just a few months after GPs were advised by NICE they should no longer routinely prescribe paracetamol at all for pain relief in osteoarthritis patients, because of concerns over an increased risk of gastrointestinal bleeding.
The SIGN guidance on chronic pain, published this month, also acknowledges emerging evidence of a potential increase in such adverse events with paracetamol, especially in combination with an NSAID.
But rather than ruling it out altogether, SIGN recommends paracetamol 1,000 mg daily can be used either alone or in combination with an NSAID as a first-line analgesic option for hip or knee pain, after non-analgesic approaches on their own have failed.
The guidance states: ‘Paracetamol (1,000 mg/day) should be considered alone or in combination with NSAIDs in the management of pain in patients with hip or knee osteoarthritis in addition to non-pharmacological treatments.’
The SIGN guidance comes after the medicines regulator flatly contradicted NICE saying it has ‘no new evidence’ to support draft guidance released by the institute in August urging GPs not to use paracetamol routinely in osteoarthritis.
The NICE guidance said if they do decide to prescribe paracetamol, GPs should use the ‘lowest effective dose’ for the ‘shortest possible time’, but the Medicines and Healthcare Products Regulatory Agency told Pulse that current evidence does not support any change in the use of paracetamol for osteoarthritis.
GP leaders said the guidance could cause further confusion among GPs who were already sceptical about the NICE evidence and who were worried about the diminishing analgesic options for patients with chronic pain.
Dr Bill Beeby, deputy chair of the GPC prescribing subcommittee, questioned whether such a low dose of paracetamol would be effective and said the SIGN guidance would not necessarily clarify the situation for GPs.
Dr Beeby said: ‘1,000 mg a day is really very low – that effectively allows you to have pain relief for six hours of the day because paracetamol doesn’t last more than six hours.
‘I think somebody needs to be helpful to GPs in quantifying these “risks” with paracetamol. It has been around a long time and evidence we’ve had up to now has certainly showed NSAIDs are much riskier.
‘This [guidance] doesn’t really help us that much and it certainly doesn’t move things too far on from the rather unacceptable and out-of-touch guidance that NICE issued.’
Dr Louise Warburton, a GPSI in rheumatology and musculoskeletal medicine in Shropshire, said the guidance seemed at odds with the NICE advice and suggested GPs should simply warn patients about the potential risks of taking paracetamol in the long term, particularly in combination with NSAIDs.
Dr Warburton said: ‘It’s all evolving evidence and opinions at the moment. If I was recommending it to patients I would warn them about taking it long term. I think it is still safe to use first line for short periods but we should use more caution in the long term.’
She added: ‘We’ve never before advised patients to be cautious about not mixing paracetamol with NSAIDs and lots of people do take both, but I think we do have to advise them not to do that now.
Dr Inam Haq, Arthritis Research UK associate medical director for policy and health promotion said: ‘The differing guidance in both documents can be seen as confusing. More research is needed on the efficacy and safety of paracetamol at lower doses. Until there is further evidence forthcoming, paracetamol use should be considered on an individual patient basis, taking into account co-morbidities and potential risks and benefits, and taken at the lowest dose for the shortest time.’
But at a recent Pulse conference on Chronic Conditions, Dr Fraser Birrell, honorary senior lecturer in rheumatology at the University of Newcastle and a member of the NICE guidelines development group that produced the draft update on osteoarthritis, defended the latest NICE advice on paracetamol.
Dr Birrell said: ‘The data show that there is a measurable risk, suggesting paracetamol has all the risks associated with [an NSAID] – in the order of magnitude of over-the-counter diclofenac. I think we need to recognise there are risks and people make a choice informed by their understanding of the benefit and of the risk.’
Update,10 January 2013: Please note that in response to an inquiry from Pulse, SIGN subsequently advised its original recommendation for use of paracetamol at 1,000 mg per day was an error. The recommendation should have stated the dose as 1,000-4,000 mg per day. The SIGN guidance has now been updated with the correct dosing range.