Rapid responses from bmj.com: Metformin and measuring renal function

doi:10.1136/bmjusa.03030004

BMJ, doi: 10.1136/bmjusa.03030004, (Published 12 April 2003)

Letter

Rapid responses from bmj.com: Metformin and measuring renal function

Following is an edited excerpt from one of the Rapid Responsesgenerated by this article, which can be read in their entiretyat http://bmj.com/cgi/eletters/326/7379/4—Editor

Andrew F Orange, pharmacist facilitator

Manawatu Independent Practice Association, Palmerston North, New Zealand andrew_orange@man.rnzcgp.org.nz

From BMJ USA 2003;Mar:132

Jones and colleagues provide compelling arguments for a review of the contraindications to metformin use. However, it is difficultto understand the rationale behind their advocacy of serumcreatinine concentration in determining the appropriatenessof metformin. Creatinine clearance is a much better objectiveassessment of renal function, and it reduces the arbitrarynature of the cutoff point for renal failure described by Joneset al. It also allows some guidance for metformin use in elderlypatients, some of whom may have significant renal impairmentbut a serum creatinine concentration within the normal range.Recent Australian guidelines on the use of oral hypoglycemicagents employ creatinine clearance as a measure of renal functionin determining an appropriate dose of metformin. These guidelinespresent a practical alternative to the view of Jones et al thatthe term "renal impairment" is vague and unhelpful.