A new study by Australian and New Zealand researchers will inform international clinical treatment guidelines for chronic kidney disease, after the team found a drug used to slow the disease in up to 20 per cent of patients is ineffective.
The Australasian Kidney Trials Network led a large, two-year study, known as CKD-FIX, to assess the effectiveness of the drug, allopurinol, in slowing the rate of decline in kidney function. The medication was developed to treat gout, but for nearly 20 years, doctors have also used it to reduce the progression of chronic kidney disease.
CKD-FIX Chief Investigator Professor David Johnson – Medical Director-Queensland Renal Transplant Service, Princess Alexandra Hospital; Professor of Medicine and Professor of Population Health, The University of Queensland (UQ); and Director, UQ Centre for Kidney Disease Research based at the Translational Research Institute – said until now there had been little robust evidence to demonstrate allopurinol’s benefit in slowing the rate of decline in kidney function.
“We felt it was important to gather evidence of allopurinol’s impact on patients with kidney disease who have never had gout,” said Professor Johnson.
“In the CKD-FIX study, we compared the use of allopurinol to a placebo and found, to our surprise, that it made no difference to the rate of kidney function decline,” he said.
“Based on these results we believe there is no benefit in prescribing this medication, unless there is an additional specific medical reason, such as gout. This much awaited, high-quality evidence will inform global clinical guidelines for patient treatment.
“It is important, though, that people with kidney disease who are already taking a medication like allopurinol to lower blood urate levels don’t abruptly stop this treatment. They should discuss their kidney care management with their doctor first.”
CKD-FIX Lead Investigator-New Zealand, Dr Janak de Zoysa from the University of Auckland and Waitemata District Health Board said trials like CKD-FIX were very important as they allowed doctors to optimise clinical practice.
"Trials which show existing treatments to be not as effective as anticipated, allow for those medications to be stopped or not started in the first place, reducing unnecessary healthcare costs,” said Dr de Zoysa.
Commercially available since the late 1960s, allopurinol helps the body reduce urate in the blood. High levels of the chemical are common among patients with chronic kidney disease, where it is associated with a higher risk of developing chronic kidney disease and its progression.
CKD-FIX Study Co-lead, The George Institute for Global Health Senior Research Fellow and St George Hospital nephrologist, Associate Professor Sunil Badve said the widely held view that elevated blood urate levels were responsible for rapid decline of kidney function was probably wrong.
“Based on our study results, it appears that elevated blood urate levels are most likely an indicator of reduced kidney function rather than a cause of reduced kidney function,” said A/Prof Badve.
The CKD-FIX study ran across 31 hospitals in Australia and New Zealand, with more than 369 patients –with stage 3 or 4 chronic kidney disease who were at increased risk of further progression – taking part in the trial.
The results from the study were published in The New England Journal of Medicine, one of the world’s leading medical journals.
In the paper, the study authors reported a 35% reduction in blood urate levels, which was maintained throughout the two-year study period for patients prescribed allopurinol. Kidney function, however, declined at similar rates for two treatment groups; allopurinol -3.33 mL/min/1.73 m2/year (95% CI -4·11 to -2·55) and control -3.23 mL/min/1.73 m2/year (95% CI -3·98 to -2·47). There was no difference in the quantity of protein in the urine and blood pressure between the groups.
Approximately 1.7 million Australians and 400,000 New Zealanders aged 18 years and over have chronic kidney disease.
Many people have a progressive decline in kidney function, also known as progression of chronic kidney disease, to the point of needing dialysis or kidney transplantation. In Australia and New Zealand, about 3600 individuals progress to end-stage kidney disease each year. There are more than 15,500 individuals receiving dialysis.
Treatments for delaying or preventing end-stage kidney disease are limited and only partially effective.
The CKD-FIX study was sponsored by The University of Queensland and funded through research grants from the National Medical and Medical Research Council (NHMRC) and the Health Research Council of New Zealand.
Hospitals taking part in the trial included: Canberra Hospital, Gosford Hospital, John Hunter Hospital, Nepean Hospital, Prince of Wales Hospital, St George Hospital, Westmead Hospital , Wollongong Hospital, Gold Coast University Hospital, Hervey Bay Hospital, Logan Hospital, Nambour General Hospital, Sunshine Coast University Hospital, Princess Alexandra Hospital, Toowoomba Hospital, Flinders Medical Centre, Royal Adelaide Hospital, Royal Hobart Hospital, Austin Health, Monash Medical Centre, The Alfred Hospital, Western Health, Melbourne Renal Research Group, Fiona Stanley Hospital, Sir Charles Gairdner Hospital, Auckland City Hospital, Christchurch Hospital, North Shore Hospital, Taranaki Base Hospital, Dunedin Hospital, Waikato Hospital, Northland District Health Board.
Media: Julia Renaud | [email protected]
About the Australasian Kidney Trials Network
The Australasian Kidney Trials Network was established in 2004 to deliver high quality clinical trials to improve the health and wellbeing of people with kidney disease. This collaborative research group engages the kidney care community to identify, conduct and support clinical trials focussed on improving appropriate patient-centred outcomes.
Photo: Professor David Johnson courtesy Metro South Health
