Evaluation of the Safety and Efficacy of Metformin Use in Hospitalized, Non–Critically Ill Patients

Abstract

Background: Contraindications and precautions to metformin have limited inpatient use, and limited evidence exists evaluating metformin in hospitalized patients. Objective: This study aimed to determine the safety and efficacy of inpatient metformin use. Methods: This study was an observational, retrospective, cohort study at an academic medical center between June 1, 2016, and May 31, 2018. Hospitalized adults with type 2 diabetes mellitus receiving at least 1 metformin dose were included. The primary endpoint was to identify hospitalized patients using metformin with at least 1 contraindication or precautionary warning against use. Secondary endpoints included assessing metformin efficacy with glycemic control, characterizing adverse outcomes of inpatient metformin, and comparing the efficacy of metformin-containing regimens. Results: Two hundred patients were included. There were 126 incidences of potentially unsafe use identified in 111 patients (55.5%). The most common reasons were age ≥65 years (47%), heart failure diagnosis (7.5%), and metformin within 48 hours of contrast (6%). Metformin was contraindicated in 2 patients (1%) with an estimated glomerular filtration rate ≤30 mL/min/1.73 m2. The overall median daily blood glucose was 146 mg/dL (interquartile range [IQR] = 122-181). Patients were divided into 3 groups: metformin monotherapy, metformin plus oral antihyperglycemic therapy, and metformin plus insulin. The median daily blood glucoses were 129 mg/dL (IQR = 110-152), 154 mg/dL (IQR = 133-178), and 174 mg/dL (IQR = 142-203; P < .001), respectively. Two patients (1%) developed acute kidney injury, and no patients developed lactic acidosis. Conclusions: Metformin was associated with goal glycemic levels in hospitalized patients with no adverse outcomes. These results suggest the potential for metformin use in hospitalized, non–critically ill patients.

Evaluation of Dipeptidyl Peptidase-IV Inhibitor Use in Hospitalized Patients With Diabetes

“…One cohort study found no difference in serious adverse events, but it was likely not powered to detect rare outcomes. 15 The present study did not specifically evaluate differences in safety events but does demonstrate that inpatient use of metformin is relatively prevalent in hospitalized patients. Although previous studies were primarily randomized controlled trials and the present study is a cohort study, this study provides additional information on inpatient diabetes management not answered by previous studies.…”