The use of oral antidiabetic agents in primary care.

Background: Guidelines and regulatory documents reflect the potential for chronic kidney disease to impact the efficacy and safety profiles of antidiabetic regimens. We describe the influence of impaired kidney function and its perception by practitioners on the pattern of antidiabetic use in Australian primary care.

Methods: Antidiabetic agent prescribing was documented for 3893 patients with type 2 diabetes from the National Evaluation of the Frequency of Renal impairment cO-existing with Noninsulin dependent diabetes mellitus (NEFRON) study. Patients with and without impaired kidney function, identified by their practitioner or defined by an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2, were systematically compared.

Results: Most patients received metformin (63%) with sulphonylureas (45%), insulin (13%) and thiazolidinediones (7%) also widely used. Contrary to prescribing guidelines, use of metformin remained frequent (53%) and the proportional usage of sulphonylureas with active metabolites was unchanged in the 23.1% of patients with an eGFR below 60 mL/min/1.73 m2. Even where prescribers identified impaired kidney function in their patients, prescribing of antidiabetic agents was not significantly modified.

Discussion: Chronic kidney disease is a common companion to type 2 diabetes in Australia. The move to automated eGFR reporting provides an important opportunity for practitioners to identify impaired kidney function and to improve their management of patients with type 2 diabetes.