Gout is common for patients with end stage kidney disease and dialysis provides an extra challenge for providing effective urate lowering therapy (ULT) in this group of patients.
A retrospective New Zealand study of more than 200 dialysis patients found more than a quarter (28.2%) of the patients had gout.
While most patients with gout (68.9%) were also on allopurinol, there was no difference in mean serum urate levels between patients on ULT and those patients who weren’t (0.38 v 0.39 mmol/L).
The study, which reviewed 936 available serum urate values for the patients, found only 23% of patients were below the target urate level of 0.36mmol/L for at least 75% of their measurements.
Target serum urate levels were achieved more often in patients on peritoneal dialysis than those on haemodialysis.
The researchers said there has been considerable controversy about the management of gout and use of allopurinol in people with significant kidney impairment and in those on dialysis.
“The British Society for Rheumatology (BSR) recommends 50–100 mg weekly of allopurinol in patients with CrCL <15 ml/min/1.73m2 although no specific advice is provided for dialysis patients.”
“In the current study the only ULT patients received was allopurinol, with a mean dose of 116mg daily. Despite the use of allopurinol, there was only a slightly higher percentage of occasions where pre-dialysis serum urate was below target in those taking ULT compared to those not on ULT (34.5% vs. 27.8% respectively).
They suggested one of the reasons was that haemodialysis cleared metabolites of allopurinol before it could have any therapeutic effect, depending on the timing of dosing.
The researchers said their findings were inconsistent with previous studies suggesting dialysis would lower serum urate and prevent gout flares.
“These data suggest that for the majority of individuals, dialysis may not be sufficient to achieve target urate and ULT may be required.”
“Larger studies to look at dosing, timing of allopurinol administrating, the effects of peritoneal dialysis on the clearance of oxypurinol and potential side effects of ULT for people treated with dialysis are required.”