Although topical NSAIDs have minimal systemic absorption, rheumatologists appear to be taking a cautious approach to using them in patients with reduced renal function, a survey of Australian Rheumatology Association (ARA) members has found.

Guidelines generally recommend that NSAIDS are avoided in patients with chronic kidney disease (eGFR <45 mL/min) due to their propensity for renovascular damage, but little is known about the risks or use of topical NSAIDs in people with CKD, say the Queensland authors of a study into their use in Australia.

Dr Matthew Terrill and colleagues in the Rheumatology and Renal Departments, Townsville Hospital, therefore surveyed members of the ARA as well as nephrologists and found that most believed that topical NSAID was widespread in patients with arthritis and musculoskeletal conditions and often occurring without the knowledge of the specialist physician.

The survey, which drew responses  from 27 rheumatologists and 33 renal physicians found that 60% would recommend topical NSAIDs even in patients with a reduced (eGFR <45 mL/min).

But in these patients  almost all would recommend the  use of topical NSAIDs only with concurrent monitoring of renal function and blood pressure. Feedback from physicians varied, with some saying they would avoid all NSAIDs – including topical NSAIDs – in patients  with an eGFR <30 mL/min, whereas two said they would have minimal concerns about topical NSAIDs in CKD patients because they were not aware of any evidence of complications reported for them. Some practitioners said they would use an NSAID with less renal clearance and others said they would advise patients to be cautious with NSAIDs if they were dehydrated and to avoid persistent  long term use.

Almost all (92%) said they had not encountered an acute kidney injury (AKI) suspected from topical NSAID use. Of the five physicians that did, three were thought to be an adverse renovascular event and two were uncertain. All patients had an eGFR <45 mL/min, all had recovery f their renal function with NSAID cessation.

Dr Terrill and colleagues said the survey, although small, provided some insight into the widespread use of topical NSAIDs in patients with impaired kidney function, and that patients often used OTC products without the knowledge of their doctor. The reports of acute kidney injury with topical NSAIDs was also cause for vigilance with their use, they added.

“This merits the judicious use of topical NSAIDs in this subset of patients and, given the apparent potential for regular use in some patients, advising patients with CKD of such risk,” they wrote.

“In this demographic, topical diclofenac may be a safer option than other topical NSAIDs, as it has a shorter half‐life and mixed renal and hepatic clearance.”