Blood glucose meters that use GDH-PQQ (glucose dehydrogenase pyrroloquinoline quinone) test strips can produce false results that lead to excessive use of insulin in patients receiving treatments containing certain non-glucose sugars, said the US Food and Drug Administration (FDA) last Friday.

If these non-glucose sugars are in a sample of patients’ blood that is tested using a GDH-PQQ glucose test strip it could prompt inappropriate clinical action such as giving patients too much insulin, “potentially resulting in hypoglycemia, coma, or death”, said the FDA in a Public Health Notification.

There is also the added risk that cases of actual hypoglycemia (lower than normal blood glucose) may go unnoticed if patients and their carers rely soley on results produced with devices that use GDH-PQQ glucose test strips, said the FDA.

The FDA Notification and accompanying Advice for Patients also lists the manufacturers and brands of GDH-PQQ glucose test strips.

The problem arises because it has come to light that GDH-PQQ also reacts with the non-glucose sugars that are present in some therapeutic products and this leads to a falsely high test results.

The non-glucose sugars that GDH-PQQ also reacts with are maltose, galactose and xylose, and these are present in products such as peritoneal dialysis solutions and certain immunoglobulins.

Patients who use these products often have very serious conditions like kidney failure and moderate to severe rheumatoid arthritis.

When blood glucose meters containing GDH-PQQ test strips are used to calculate glucose levels in patients receiving these therapies they will get a reading that is much higher than it should be and this could lead to them using too much insulin.

Most blood glucose meters based on GDH-PQQ test strips are used in health care facilities, said the FDA, whose advice is that they should switch to laboratory assay methods to measure glucose in patients who are also receiving an interfering product.

The Public Health Notification also lists recommendations on how to minimize the risk of potential shortages until more non-GDH-PQQ strips and meters are available.

— FDA Public Health Notification

— info on blood sugar management (dLife)

Source: FDA, dLife.

Written by: Catharine Paddock, PhD