December 2020: Diabetes Management Workgroup Interventions

Diabetes Medication Management Workgroup Overview

Affinia Health Network is participating in a statewide collaboration to specifically improve diabetes care, known as the Diabetes Medication Management Workgroup. The goal of this workgroup is to provide primary care clinicians with evidence-based guidance on type 2 diabetes management to improve quality of care, reduce inappropriate (or inefficient) use of pharmaceuticals, and lower the cost of care. This collaboration will analyze data, identify opportunities, and develop workflows and interventions to further improve care.
For pilot phases of this work, it was decided to focus on our own Colleague Health Plan as the workgroup identified variability in prescribing across the state and within local regions when analyzing our data. When selecting pilot interventions for this population, the workgroup ranked possible ideas based on data availability and clinical impact of the potential interventions. The first two interventions the workgroup decided to focus on were increasing utilization of metformin in patients prescribed insulin and eliminating the co-prescribing of dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide (GLP-1) agonists.

Intervention: Increase Use of Metformin in Patients Using Insulin


American Diabetes Association recommendations:

  • Metformin is recommended first-line for patients with type 2 diabetes mellitus based on efficacy, minimal risk of hypoglycemia, weight-neutral or weight-loss classification, overall side-effect profile, and cost.
  • Metformin should be added to insulin as long as the patient does not have an intolerance to metformin and/or metformin is not contraindicated (e.g., renal dysfunction).
  • Additional monitoring including complete blood count and vitamin B12 may be considered if a patient is at risk for developing vitamin B12 deficiency (e.g., anemia, peripheral neuropathy).

Clinical Impact3-4

Patients with type 2 diabetes treated with both insulin and metformin resulted in better blood glucose control compared to patients treated with insulin alone. In addition, insulin requirements and weight gain were decreased in patients taking both insulin and metformin versus those taking insulin alone.

Financial Impact3-4

Metformin may reduce insulin use by 7-20 units per day depending on variables such as baseline total insulin use, metformin dose, etc. If metformin use can save 10 units of insulin per day, at 33 cents per unit, then metformin combined with insulin use may save an estimated $1,200 per year per patient in pharmaceutical costs alone.

Benefits of Intervention1-4

Intervention: DPP-4 Inhibitors and GLP-1 Agonists Co-Prescribing


There is no data in the guidelines to support concurrent use of a DPP-4 inhibitor (e.g., alogliptin, saxagliptin) and a GLP-1 agonist (e.g., exenatide, dulaglutide) together.

  • Generally, concurrent use of these agents is considered a duplication of therapy as the mechanism of action for each agent is closely related.
  • DPP-4 is an enzyme that rapidly inactivates both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP). By blocking the DPP-4 enzyme, the half-life of endogenously produced GLP-1 and GIP is prolonged.

Clinical Impact1,7

  • 2020 American Diabetes Association guidelines support the use of:
    • GLP-1 agonists for patients with established atherosclerotic cardiovascular disease (ASCVD) or high ASCVD risk and patients trying to minimize weight gain or promote weight loss.
    • Either GLP-1 agonists or DPP-4 inhibitors may be considered when there is a compelling need to minimize hypoglycemia.
  • A case series by Lajthia et al. (2019) found that patients receiving the combination of GLP-1 agonists and DPP-4 inhibitors only showed a 0.9% reduction in the group without insulin and a 0.8% reduction in the group with insulin when a GLP-1 agonist was added to a DPP-4 inhibitor.
    • It appears combining the two agents is likely not providing synergistic effects.


Co-prescribing of GLP-1 agonists and DPP-4 inhibitors is considered duplication of therapy without significant benefits in A1c reduction while increasing the cost of care for the patient and the health system.

  • In general, GLP-1 agonists should be considered the preferential agent due to clinical data.

Next Steps

  • Leverage team-based approach: provider, care manager, pharmacist, other staff members.
  • Monitor progress by tracking metric performance and share performance with network.
  • Report findings of intervention impact to stakeholders.


  1. Riddle M, Bakris G, Blonde L, Boulton A, D’Alessio D, DiMeglio L, et al. American diabetes association standards of medical care in diabetes-2020. Diabetes Care. 2020 Jan;43.
  2. Ting RZ, Szeto CC, Chan MH, Ma KK, Chow KM. Risk factors of vitamin B(12) deficiency in patients receiving metformin. Arch Intern Med. 2006;166(18):1975-1979.
  3. Wulffelé MG, Kooy A, Lehert P, et al. Combination of insulin and metformin in the treatment of type 2 diabetes. Diabetes Care. 2002;25(12):2133-2140.
  4. Church TJ, Haines ST. Treatment Approach to Patients With Severe Insulin Resistance [published correction appears in Clin Diabetes. 2016 Jul;34(3):168]. Clin Diabetes. 2016;34(2):97-104.
  5. Lexicomp OnlineTM [Internet]. Hudson (OH): Lexicomp. C1978 – .Lexi-drugs online; [cited 2020 Sep 4].
  6. Qiao Q, Ouwens MJ, Grandy S, Johnsson K, Kostev K. Adherence to GLP-1 receptor agonist therapy administered by once-daily or once-weekly injection in patients with type 2 diabetes in Germany. Diabetes Metab Syndr Obes. 2016;9:201-205. Published 2016 Jun 28.
  7. Lajthia E, Bucheit JD, Nadpara PA, et al. Combination therapy with once-weekly glucagon like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in type 2 diabetes: a case series. Pharm Pract (Granada). 2019;17(4):1588. doi:10.18549/PharmPract.2019.4.1588
  8. George CM, Brujin LL, Will K, Howard-Thompson A. Management of Blood Glucose with Noninsulin Therapies in Type 2 Diabetes. Am Fam Physician. 2015;92(1):27-34.
  9. Filippatos TD, Panagiotopoulou TV, Elisaf MS. Adverse Effects of GLP-1 Receptor Agonists. Rev Diabet Stud. 2014;11(3-4):202-230.
About the author

PharmD, PGY-2 Pharmacy Resident

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