Medication adherence assessment: high accuracy of the new Ingestible Sensor System in kidney transplants

Transplantation. 2013 Aug 15;96(3):245-50. doi: 10.1097/TP.0b013e31829b7571.


Background: This open-label single-arm exploratory study evaluated the accuracy of the Ingestible Sensor System (ISS), a novel technology for directly assessing the ingestion of oral medications and treatment adherence.

Methods: ISS consists of an ingestible event marker (IEM), a microsensor that becomes activated in gastric fluid, and an adhesive personal monitor (APM) that detects IEM activation. In this study, the IEM was combined to enteric-coated mycophenolate sodium (ECMPS). Twenty stable adult kidney transplants received IEM-ECMPS for a mean of 9.2 weeks totaling 1227 cumulative days.

Results: Eight patients prematurely discontinued treatment due to ECMPS gastrointestinal symptoms (n=2), skin intolerance to APM (n=2), and insufficient system usability (n=4). Rash or erythema due to APM was reported in 7 (37%) patients, all during the first month of use. No serious or severe adverse events and no rejection episode were reported. IEM detection accuracy was 100% over 34 directly observed ingestions; Taking Adherence was 99.4% over a total of 2824 prescribed IEM-ECMPS ingestions. ISS could detect accurately the ingestion of two IEM-ECMPS capsules taken at the same time (detection rate of 99.3%, n=2376).

Conclusions: ISS is a promising new technology that provides highly reliable measurements of intake and timing of intake of drugs that are combined with the IEM.

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Immunosuppressive Agents / therapeutic use*
  • Kidney Transplantation*
  • Male
  • Medication Adherence*
  • Middle Aged
  • Mycophenolic Acid / analogs & derivatives*
  • Mycophenolic Acid / therapeutic use
  • Tablets, Enteric-Coated


  • Immunosuppressive Agents
  • Tablets, Enteric-Coated
  • Mycophenolic Acid