Rob Walker

Managing medications with impaired kidney function.

The support Professor Rob Walker’s research has received from the Otago Medical Research Foundation over several decades has had an impact on understanding and managing kidney disease across the globe.

Professor Walker is interested in how individuals with impaired kidney function handle medication. His research has focused on the effect of a range of prescribed drugs on kidney function - how some medications may lead to progressive kidney injury, or how impaired kidney function alters the way in which the body clears different medications.

He has also been involved in supporting other researcher’s projects as a member of the Foundation’s scientific committee for many years.
The Foundation has funded several of his research projects investigating the effects of lithium – a drug which successfully treats mood disorders but can alter how the kidney concentrates urine, and longer-term may induce a slowly progressive decline in kidney function.

Earlier translational research at the University of Otago looked at lithium-induced alterations in kidney-concentrating ability, asking what changes can occur following lithium exposure. Subsequent studies have focused on the pathways associated with the development of scarring (chronic interstitial fibrosis) following lithium exposure.

The focus was on differentiating normal cell activity and pathways that result in chronic injury. The impact of amiloride (an old diuretic drug) was shown to significantly reduce lithium-induced injury, offering potential for a new therapeutic agent to reduce the progression of chronic kidney injury.
These results were published in the Nature journal Scientific Reports.

Managing medications with impaired kidney function

Most medications are trialled in individuals with normal kidney function before they enter clinical practice. Less is known about how these medications react in individuals with impaired kidney function.

A focus of Professor Walker’s investigations with the support of the Foundation has been to look at how some of these medications are handled with impaired kidney function. He has examined how various prescription drugs, including antibiotics, are handled and eliminated in the setting of impaired kidney function or by haemodialysis or peritoneal dialysis (used to manage individuals with kidney failure).

His most recent research looked at how allopurinol, a drug used to treat gout, is cleared in kidney patients receiving peritoneal dialysis – the aim being to quantify the impact of dialysis on drug handling which in turn will lead to safe prescribing of allopurinol.

The objective is guiding clinicians on drug prescribing appropriate for individuals suffering from kidney disease with an individualised treatment that addresses patient safety as well as efficacy.

The benefits of Otago Medical Research Foundation funding

All of Professor Walker’s OMRF-sponsored projects are on a smaller-scale but together have added up to a significant understanding of kidney function – the Dunedin research published in leading peer-reviewed journals (with acknowledgement of the sponsorship from the OMRF), contributing substantially to world knowledge on kidney health.

Many of Professor Walker’s projects have been an important means to getting Dunedin’s medical students and trainees involved in clinical studies, providing them with valuable research and analysis skills as part of their training.
He points out that many of the OMRF-sponsored studies (not just his studies) provide the necessary data and proof of concept enabling applications to other funders such as Health Research Council for larger-scale studies to come up with scientific advances that can be published in prestigious journals and shared with the global community.

“The Foundation gets so many high quality proposals - it makes funding decisions a constant challenge. But without their vital “seed” support, many researchers would simply not get their projects off the ground.”