Endocrine Abstracts

Introduction and Objectives: Extended-release metformin (XRM) is recently available in Spain as a fixed combination with sitagliptin, but not in monotherapy. Its tolerance is clearly superior to that of conventional metformin, and since 2005 the NICE guidelines for type 2 diabetes mellitus (T2DM) recommend its use in patients with metformin-caused gastrointestinal disturbances. We assessed the efficacy and tolerability of XRM/sitagliptin in patients with T2DM previously labelled as metformin-intolerant and treated with a DPP4 inhibitor (DPP4i), and additionally analyzed the data for patient satisfaction.

Patients and Methods: Consecutive patients with T2DM, HbA1c >7% and GFR (CKD-EPI) >45 mL/min/1.73m² labelled as metformin-intolerant due to gastrointestinal symptoms, and treated with a DPP4i were switched to the 50 mg sitagliptin plus 1000 mg XRM combination, taking 1 pill daily in the first month and afterwards 2 pills if the tolerance was good. The mean reductions in HbA1c were 0.6% with 1 pill and 0.9% with 2 pills (both P<0.01). The patients were contacted for a short web-based questionnaire in order to assess their satisfaction with the switch from DPP4i to the XRM/sitagliptin combination. This was categorically expressed choosing one of 5 icons conventionally considered as representing “very poor, poor, fair, good or very good” satisfaction (Likert scale); there was also an option for “no opinion”. Tolerance data were obtained by questionnaire in the follow-up visit. All Included patients granted informed consent.

Results: Satisfaction data could be obtained from 70 of a total 72 patients, 62 through the web, 5 by phone and 3 presentially, but the questioner was never the prescribing physician. 39 (55.7%) of the patients reported “very good” satisfaction, 14 (20.0%) “good” satisfaction, 9 (12.6%) “fair” satisfaction, 4 (5.7%) “poor” satisfaction, 2 (2.9%) “very poor” satisfaction, and 2 (2.9%) reported no opinion. 51 patients (73%) tolerated 2 tablets of XRM/sitagliptin (1000/50 mg); 8 (11%) tolerated 1 tablet and 11 (16%) did not tolerate any. A backwards stepwise logistic regression identified the lack of adverse effects as the only independent predictor of “good” or “very good” satisfaction, while the changes in HbA1c, fasting glucose, body weight, etc. did not predict satisfaction.

Conclusions: A large majority of the patients with T2DM labelled as metformin-intolerant and treated with a DPP4i tolerated the XRM/sitagliptin combination. Patient satisfaction with the switch was high, with 3/4 of them reporting it as “good” or “very good”, and was driven by the absence of adverse effects.