The European Medicines Agency (EMA) has announced that metformin-containing medicines can now be used in patients with moderately reduced kidney function — defined as a glomerular filtration rate (GFR) of 30 to 59 mL/min — for the treatment of type 2 diabetes.
The product information for these medicines will be updated to revise the current contraindication and give information about doses, monitoring, and precautions in patients with reduced renal function, says the EMA.
Metformin has traditionally been contraindicated in moderate renal impairment because it can increase the risk of a rare but serious complication — lactic acidosis — and it had been thought that those with reduced kidney function were at higher risk of this side effect.
However, "after considering the scientific literature, clinical data, epidemiological studies, and clinical guidelines from medical bodies, the EMA concluded that the large patient population with moderately reduced kidney function can benefit from use of metformin," the agency announced.
Clear dosing recommendations and monitoring before and during treatment aim to minimize any possible increased risk in these patients, it adds, while stressing that the contraindication for patients with severely reduced kidney function (GFR < 30 mL/min) will remain.
The EMA also notes that the current information regarding metformin and use in renal impairment "varies between countries and products"; the aim of this new ruling "is to ensure that the same advice is given to all patients in the EU."
Following the FDA's Lead
The EMA announced in February of this year, at the request of the Dutch Medicines Agency, that it would review recommendations on all metformin-containing medicines in the European Union with regard to how they are used in patients with moderate renal impairment, in part to try to harmonize advice on this throughout the European Union.
The issue of whether metformin is underprescribed in patients with type 2 diabetes because of these concerns about its use in those with mild to moderate renal insufficiency has been high on the agenda of endocrinologists for some time, and recommendations on this do vary around the world.
In April this year, the Food and Drug Administration (FDA) announced that it was recommending that metformin-containing medications could now be used in patients with moderate renal impairment, a decision that was favorably received by doctors there who have long been frustrated by this restriction.
The FDA advised metformin manufacturers to revise their label information to incorporate both the new guidance and eGFR as a new measure of kidney function to determine whether a patient can receive the drug. The FDA had previously used serum creatinine concentrations but said eGFR is superior because it also factors in a patient's age, sex, race, and other parameters.
EU Relaxes Metformin Indication to Include Moderate CKD. Medscape. Oct. 14, 2016.