Home / Resources / Disasters Averted / Always Reevaluate Background Therapies When Starting a New Glucose-Lowering Agent

Always Reevaluate Background Therapies When Starting a New Glucose-Lowering Agent

Mar 30, 2021

Author: Catherine Chung, PharmD Candidate 2024 & Joshua J. Neumiller, PharmD, CDCES, FADCES, FASCP

The importance of evaluating background therapies in diabetes care

We were asked to consult on a case involving BK, a 74-year-old man with type 2 diabetes (T2D) of 12 years duration. He was a retired restaurant manager who lived with his wife of 52 years. BK had a positive history of tobacco smoking (2 packs per day for 35 years), but he quit ten years ago following his grandson’s birth. He monitors his blood glucose level two to three times daily at home with a glucose meter. His most recent A1C was 7.2%. We were providing a medication review for BK shortly following hospitalization for myocardial infarction (MI).  


The patients medication list at the time of the medication review was as follows: 

  • Victoza (liraglutide) 0.6 mg subcutaneously once daily (newly prescribed) 
  • Janumet (sitagliptin/metformin) 50/1000 mg twice daily 
  • Hyzaar (losartan/HCTZ) 100/25 mg once daily 
  • Metoprolol (Toprol XL) 100 mg once daily (newly prescribed) 
  • Lipitor (Atorvastatin) 40 mg once daily  
  • Aspirin EC 81 mg once daily 

Liraglutide was added to the medication regimen to mitigate BKs cardiovascular risk post-MI. The 2021 American Diabetes Association (ADA) Standards of Medical Care recommend the addition of a GLP-1 receptor agonist or SGLT2 inhibitor with proven cardiovascular disease (CVD) benefit in appropriate patients.1 Liraglutide is an agent from the GLP-1 RA class with demonstrated CVD benefit, with the LEADER cardiovascular outcome trial showing significant advantage on the primary composite outcome (3-point MACE) and for cardiovascular-related and all-cause mortality.2 Based on these findings, Victoza has a labeled indication to reduce the risk of major adverse cardiovascular events (MACE) in adults with T2D and established CVD.3 

Upon reviewing BK’s medication list, we found that the liraglutide was added to background Janumet (sitagliptin/metformin). Both GLP-1 RAs and DPP-4 inhibitors (such as liraglutide and sitagliptin, respectively) work to augment the incretin effect. GLP-1 RAs are more potent in their glucose-lowering and weight loss effects when compared to DPP-4 inhibitors. While the combination is not harmful, no additional glucose-lowering would be expected with continued use of a DPP-4 inhibitor in patients receiving GLP-1 RA therapy. Considering the lack of additive efficacy and the high cost of this combination, it is recommended that background DPP-4 inhibitor therapy be discontinued when a patient is initiated on a GLP-1 RA.4  

In this case, we recommended discontinuation of BKs Janumet prescription and obtained a new prescription for metformin 1000 mg twice daily. We discussed the rationale for this change with BK and provided additional appropriate education about his liraglutide (use of the pen device, appropriate injection technique, need for dose titration, etc.). 

Lessons Learned 

  • It is essential to evaluate background therapies when initiating a new medication to avoid therapeutic duplication. 
  • GLP-1 RA and SLGT2 inhibitor use is expanding to include use for mitigating cardiovascular and kidney risk in select populations. 
  • If starting a GLP-1 RA in a patient, it is recommended to discontinue background DPP-4 inhibitor therapy. 



  1. American Diabetes Association. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Medical Care in Diabetes—2021. Diabetes Care 2021;44(Suppl. 1): S111-S124.  
  2. Marso SP, Daniels GH, Brown-Frandsen K, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes. N Engl J Med 2016;375(4):311-322. 
  3. Victoza® (liraglutide) injection. Prescribing information. Novo Nordisk, Inc., Plansboro, NJ. November 2020. 
  4. Davies MJ, D’Alessio DA, Fradkin J, et al. Management of hyperglycemia in type 2 diabetes, 2018. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2018;41(12):2669-2701.  



If you have a “Diabetes Disaster Averted” story like this one about reevaluating background therapies, please let us know! If we feature your Disaster Averted in our Diabetes Clinical Mastery Series e-newsletter, you will receive a $25 gift card. Please click here to submit a short summary of the incident, what you feel you learned from handling the incident, and your name and title. If you prefer to remain anonymous, please let us know, but still give us your name and address (so we can send you the gift card).






Copyright © 2021 HIPER LLC