GPs should urge patients taking ACE inhibitors or angiotensin receptor blockers (ARBs) who fall ill to come and see them, after researchers said increased use of the drugs is partly to blame for rising admissions for acute kidney injury (AKI).
The team from Cambridge University estimated that the rise in prescriptions for ACE inhibitors and ARBs may have accounted for around 15% of the rise in AKI hospitalisations over the period 2007/08 to 2010/11 – or one in seven of the extra AKI admissions recorded over this time.
They found a 16% increase in prescriptions of ACE inhibitors and ARBs between the years 2007/08 and 2010/11, which coincided with a 52% increase in AKI admissions at hospitals in England.
The researchers estimated over 1,600 admissions would have been prevented had prescribing of ACE inhibitors and ARBs stayed at 2007/08 levels.
They urged GPs to remind patients on ACE inhibitors or ARBs to make an appointment if they become acutely unwell and dehydrated, for example due to an infection, in case they need to stop taking their medication temporarily.
The team analysed prescribing data from all general practices in England to determine the total number of prescriptions of ACE inhibitors and ARBs that were dispensed for each practice, weighted for the practice population age and sex demographics, and linked these to Hospitals Episodes Statistics data on admissions.
After adjusting for the underlying increase in reporting of AKI and conditions that also cause AKI, the authors found that GP prescribing rates were ‘independently associated’ with AKI admission rates.
They estimated the rise in ACE inhibitor/ARB use in a typical practice corresponded with a 5% increase in AKI hospitalisations. From this, they predicted 1,636 AKI admissions could have been avoided if prescribing rates had stayed at 2007/08 levels – equivalent to 14.8%, or one in seven, of the total increase in AKI admissions.
NICE recommends patients should have renal function closely monitored as they have their dose of ACE inhibitor or ARB titrated and reviewed annually, while patients with chronic kidney disease should stop taking their medication if they feel acutely unwell.
The study concluded: ‘Our analyses provide strong evidence that, at the level of the general practice, the increase in prescribing is associated with the increase in hospitalisation, and indeed may account for almost 15% of the total increase in AKI admissions.’
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Lead author Dr Rupert Payne, clinical lecturer at the University of Cambridge and a GP in the city, told Pulse GPs should urge caution in all their patients, however, given that many elderly patients and those with other conditions could also be at risk.
Dr Payne said: ‘These drugs are incredibly commonly used so this is simply a reminder about the guidance, which is to encourage patients with acute concurrent illness to visit the GP to have their kidney function checked.
Some patients are at particularly high risk of AKI such as those with existing chronic kidney disease, and they should certainly be made aware of this problem. However, these drugs are used in many patients, such as the elderly and those with lots of comorbidities and taking many additional medications, in whom we don’t have enough evidence from clinical trials about the benefit to harm ratio. So we should err on the side of caution and educate all patients about the potential risks.’
Dr Kathryn Griffith, RCGP clinical champion for kidney care and a GP in York, said that there was a ‘massive evidence base’ for using ACE inhibitors and ARBs, but GPs should take extra care when prescribing the drugs in the elderly with pre-existing CKD.
She said: ‘They should also be given advice about the need for drug holidays should they become dehydrated where AKI is risk and this is an area of care which is often lacking.’
Dr Griffith added: ‘I think that perhaps we have become blase about the uses of these RAAS blocking drugs, we have moved from the days when we admitted people to hospital for the first dose, to using them in a large group of patients many of whom have co-existing CKD. Prescribers need to consider the risks and benefits of any medication and should review doses and treatment choices should the patients clincal condition change.’
Dr Andrew Green, chair of the GPC prescribing subcommittee and a GP in Hedon, East Yorkshire, said: ‘This study illustrates the importance of GPs being able to adjust therapy to the individual patient, and not being pressured into the rigid chasing of treatment targets in people for whom this is inappropriate.
‘GPs need to be aware of the importance of checking renal function in patients receiving ACE inhibitor/ARB medications, especially during periods of intercurrent illness, and patients need to be aware of the importance of attending their GP practice for their annual review.’
PLoS ONE 2013, available online 6 November
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