Singapore - There have been recent adverse reports in Australia, Canada and the United Kingdom of injuries caused by falsely elevated blood glucose readings in diabetic patients who are using peritoneal dialysis solution that contains icodextrin as an ingredient (e.g. Extraneal®) and blood glucose monitoring systems that are based on the glucose dehydrogenase-pyrroloquinolinequinone (GDH-PQQ) method. Although this is a known drug-device interaction, such serious mishaps which could be fatal, continue to be reported overseas. In Singapore, no similar case has been reported.

Icodextrin, a glucose polymer, is broken down into maltose in the body. The accumulation of blood maltose can interact with glucose monitoring systems that are not glucose-specific (e.g. those using the GDH-PQQ method) and give rise to falsely elevated glucose readings. As a result, patients may receive an excessive dose of insulin leading to a hypoglycaemic episode. On the other hand, cases of hypoglycaemia might not be treated if their hypoglycaemic states are masked by glucose readings that are falsely elevated into the normal range.

To reduce the risk of drug-device interaction, the following preventive measures are recommended:

• Diabetic patients who require dialysis and are prescribed Extraneal® should be issued with a Safety Alert Card provided by the manufacturer. Patients should be advised to present this card to any attending medical personnel.

• Patients on Extraneal® should use only glucose-specific meters that are not subjected to interference from icodextrin metabolites. Patients should be given a specific instruction on the appropriate type of home blood glucometer that they should use and to verify the suitability of the glucometers with the companies distributing the meters.

• Patients should be reminded to read the product package information leaflet of the glucose monitoring system before using the product.

Reference: Safety reports. http://www.hsa.gov.sg