Prescribing patterns of adjunctive therapy for the treatment of type 1 diabetes mellitus among Australian endocrinologists

Abstract

Background: Many people living with type 1 diabetes (type 1 diabetes mellitus (T1DM)) do not meet glycaemic targets. Adjunctive therapies have both risks and metabolic benefits and may have a role in selected patients. Aim: To review the prescribing patterns of adjunctive therapy for the treatment of T1DM diabetes in Australia. Methods: We conducted an online survey of Australian endocrinologists and endocrinology registrars. We surveyed the frequency of, motivations and concerns regarding the prescription of metformin, dipeptidyl peptidase-4 (DPP-IV) inhibitors, sodium-glucose transport protein 2 (SGLT-2) inhibitors and glucagon-like peptide 1 receptor agonist (GLP1RA) in T1DM. Results: Fifty-two practitioners participated. Most respondents (94%) had prescribed adjuncts for the treatment of T1DM in some form. Weight (89%), large insulin doses (73%), glycaemic variability (52%), high HbA1c (48%) and the presence of cardiovascular disease (48%) were the most common factors determining the use of adjuncts. The most commonly prescribed adjuncts were metformin (94%) and SGLT-2 inhibitors (65%). Respondents who had never prescribed an SGLT-2 inhibitor (n = 18) reported risk of diabetic ketoacidosis (DKA) (100%), off-label status (39%), lack of evidence (39%), withdrawal of support from the European Medicines Agency (17%) and cost (17%) as factors contributing to their decision. Thirty-one respondents (60%) had prescribed a GLP1RA. Among those who had never prescribed a GLP1RA (n = 21), off-label status (57%), lack of evidence (48%), cost (38%) and expected lack of efficacy (14%) were factors affecting their decision. Only five respondents (10%) had prescribed a DPP-IV inhibitor. Conclusion: Australian endocrinologists commonly prescribe adjuncts to address cardiometabolic concerns in T1DM. DKA risk and off-label status are significant factors contributing to reluctance to prescribe.