EULAR recommendations on the dosing of allopurinol in gout patients with renal impairment could contribute to sub-optimal care, experts warn.
In a letter published in the Annals of the Rheumatic Diseases the international team of rheumatologists said they were concerned by a recommendation in the guidelines that advised clinicians to adjust the dose of allopurinol in people with renal impairment based on creatinine clearance (CrCL).
EULAR guideline recommendation #9: In patients with renal impairment, the allopurinol maximum dosage should be adjusted to creatinine clearance. If the SUA target cannot be achieved at this dose, the patient should be switched to febuxostat or given benzbromarone with or without allopurinol, except in patients with estimated glomerular filtration rate <30 mL/min.
According to the authors, this practice has been a major contributing factor to the under-treatment of gout.
The team of gout experts, including Professor Nicola Dalbeth and Professor Lisa Stamp from New Zealand, also took issue with advice in the guidelines against a dose-escalation approach in this group of patients.
While they acknowledged that renal impairment was a major risk factor for allopurinol hypersensitivity syndrome/severe cutaneous reactions (SCARs), they said there was no evidence that long-term restriction of allopurinol dose according to CrCL lowered the risk in patients who tolerated low starting doses of allopurinol.
“The approach advocated by the European League Against Rheumatism panel could lead to a clinical situation where patients may be exposed to potential risks of allopurinol, without the benefits achieved by careful dose escalation to achieve serum urate target,” they wrote.
Furthermore, they said that focusing on the maximum dose of allopurinol, rather than the starting dose, may inadvertently reinforce fears about allopurinol use in patients with renal dysfunction when recent data shows it can be used safely.
“Recommending dosing of allopurinol based on CrCL in the absence of evidence to support this practice will not improve the historically poor management of gout in patients with renal disease,” they concluded.