Interference Assessment of Various Endogenous and Exogenous Substances on the Performance of the Eversense Long-Term Implantable Continuous Glucose Monitoring System

Abstract

Background: A variety of prescriptions and over-the-counter medications interfere with transcutaneous continuous glucose monitoring (CGM) sensors. This study characterized the interference profile of the Eversense^® CGM System (Senseonics, Inc., Germantown, MD), which has a different mechanism of glucose detection than other CGM systems.

Materials and methods: Sensor bias (sensor glucose concentration measurement - plasma glucose concentration measured by a reference test) was measured in vitro against 41 different substances at supratherapeutic/supraphysiologic plasma concentrations. Testing was performed using a paired-sample method adapted from the Clinical and Laboratory Standards Institute guidance document EP7-A2. Any substance producing sensor bias that exceeded the International Organization for Standardization (ISO) document 15197:2013 limits was then tested using an in vitro dose-response method to determine whether the concentration producing a significant sensor bias was within physiologic/therapeutic concentration ranges.

Results: Eight of 41 substances produced a sensor bias that exceeded ISO 15197:2013 limits when tested in vitro at supratherapeutic/supraphysiologic plasma concentrations. Only two of these substances (tetracycline and mannitol) exceeded bias limits within therapeutic concentration ranges. Notably, neither acetaminophen nor ascorbic acid, which are substances reported to interfere with other CGM systems, produced sensor bias that exceeded ISO limits when used at physiologic concentrations.

Conclusions: Although tetracycline and mannitol interfered with the Eversense sensor, substances frequently reported to interfere with enzymatic, electrochemical-based transcutaneous CGM systems, such as acetaminophen and ascorbic acid, did not affect Eversense readings.

Keywords: Continuous glucose monitoring; Drug interferences; Sensor.

FIG. 1.

Eversense^® implantable glucose sensor. DXA, dexamethasone acetate; PMMA, poly(methyl methacrylate).

FIG. 2.

Equilibrium binding of glucose to the glucose indicating polymer and effects on fluorescence. R₂ denotes connectivity to the indicator polymer backbone. LED, light-emitting diode.