FDA Issues Glucose Meter Safety Warning

The Food and Drug Administration (FDA) is warning patients and health careproviders that several blood glucose testing devices and strips use enzymesthat confuse glucose with galactose, maltose, or xylose.

Precautions should be taken with patients receiving parenteral productswith these sugars, which may cause certain blood glucose meters to readfalsely elevated glucose levels, according to the FDA.

“It's not much of a problem in day-to-day life, but since thosesugars are sometimes used in parenteral feeding and in various diagnostictests in the hospital setting, several people have died as a result of insulinshock when they were treated with large doses of insulin for `blood glucose'levels ≥450 mg/dl when they were actually normoglycemic,” says MattPetersen, director of scientific and medical information for the AmericanDiabetes Association (ADA). “Use of bedside self-monitoring usingsusceptible testing equipment instead of laboratory blood glucose measurementincreases the chance that a mistake will bemade.”

The FDA issued the safety alert November 9 to make health careprofessionals aware of the potentially life-threatening dangers of falselyelevated glucose readings in patients receiving parenteral products containinggalactose, maltose, or oral xylose, who also test their blood glucose usingmonitoring systems based on a glucose dehydrogenase pyrroloquinoline-quinone(GDH-PQQ) method.

Other medical products that may contain or be metabolized to galactose,maltose, or xylose include intravenous immunoglobulin solutions and peritonealdialysis solutions.

Self-monitoring glucose devices used by diabetic patients at home and inpoint-of-care settings as well as laboratory glucose assays all use a GDH-PQQ,glucose dehydrogenase nicotinamide adenine dinucleotide (GDH-NAD), glucoseoxidase, or glucose hexokinase test method. The test method is clearly markedin the device labeling and in the operator's manual.

The GDH-PQQ–based systems are nonspecific for glucose and, in thepresence of galactose, maltose, or xylose, may report falsely elevated glucosereadings. Glucose monitoring systems that use GDH-NAD, glucose oxidase, orglucose hexokinase methods are not affected by the presence of galactose,maltose, or xylose.

“The situation obviously has greatest import for hospitals, but it isalso true that the errors possible have the greatest risk in thissetting,” says Nathaniel G. Clark, MD, MS, RD, national vice presidentof clinical affairs for ADA. ▪

Avoid False Readings

To help prevent false readings, personnel performing glucose monitoringshould do the following:

1. Know whether their glucose testing method uses GDH-PQQ, GDH-NAD, glucoseoxidase, or glucose hexokinase to measure the sugar level. The testing methodis specified in the device operating manual and can be obtained from thedevice manufacturer.

2. Use only GDH-NAD, glucose oxidase, or glucose hexokinase methods if thepatient has received intravenous immunoglobulin solutions within the last 24hours, has taken oral xylose within the last 24 hours, or is on peritonealdialysis.

Source: FDA