Association between sodium-glucose cotransporter 2 (SGLT2) inhibitors and lower extremity amputation: A systematic review and meta-analysis.

BACKGROUND: The association between sodium-glucose cotransporter 2 inhibitors (SGLT2i's) and lower extremity amputation is unclear. PURPOSE: To systematically review randomized control trials (RCTs) and observational studies quantifying risk of lower extremity amputations associated with SGLT2i use. DATA SOURCES AND STUDY SELECTION: We searched PubMed, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials from January 2011 to February 2020 for RCTs and observational studies including lower extremity amputation outcomes for individuals with type 2 diabetes mellitus treated with SGLT2i's vs. alternative treatments or placebo. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data. MAIN OUTCOMES AND MEASURES: Our primary outcome was risk of lower limb amputation. Secondary outcomes included peripheral arterial disease, peripheral vascular disease, venous ulcerations, and diabetic foot infections. We also evaluated the risk of bias. We conducted random and fixed effects relative risk meta-analysis of RCTs. RESULTS: After screening 2,006 studies, 12 RCTs and 18 observational studies were included, of which 7 RCTs and 18 observational studies had at least one event. The random effects meta-analysis of 7 RCTs suggested the absence of a statistically significant association between SGLT2i exposure with evidence of substantial statistical heterogeneity (n = 424/23,716 vs n = 267/18,737 in controls; RR 1.28, CI's 0.93-1.76; I2 = 62.0%; p = 0.12) whereas fixed effects analysis showed an increased risk with statistical heterogeneity (RR 1.27, 1.09-1.48; I2 = 62%; p = 0.003). Subgroup analysis of canagliflozin vs placebo showed a statistically significantly increased risk in a fixed effects meta-analysis (n = 2 RCTs, RR 1.59, 1.26-2.01; I2 = 88%; p = 0.0001) whereas the meta-analysis of dapagliflozin or empagliflozin (n = 2 RCTs each) and a single RCT for ertugliflozin did not show a significantly increased risk. The findings from observational studies were too heterogeneous to be pooled in a meta-analysis and draw meaningful conclusions. Both randomized and observational studies were of generally good methodological quality. CONCLUSIONS: Overall, there was no consistent evidence of SGLT2i exposure and increased risk of amputation. The increased risk of amputation seen in the large, long-term Canagliflozin Cardiovascular Assessment Study (CANVAS) trial for canagliflozin, and select observational studies, merits continued exploration.

Evaluation of the Extended-Release/Long-Acting Opioid Prescribing Risk Evaluation and Mitigation Strategy Program by the US Food and Drug Administration: A Review.

Importance: Extended-release/long-acting (ER/LA) opioids have caused substantial morbidity and mortality in the United States, yet little is known about the efforts of the US Food and Drug Administration (FDA) and drug manufacturers to reduce adverse outcomes associated with inappropriate prescribing or use. This review of 9739 pages of FDA documents obtained through a Freedom of Information Act request aimed to investigate whether the FDA and ER/LA manufacturers were able to assess the effectiveness of the ER/LA Risk Evaluation and Mitigation Strategy (REMS) program by evaluating manufacturer REMS assessments and FDA oversight of these assessments. Observations: The REMS program was implemented largely as planned. The FDA's goal was for 60% of ER/LA prescribers to take REMS-adherent continuing education (CE) between 2012 and 2016; 27.6% (88 316 of 320 000) of prescribers had done so by 2016. Audits of REMS programs indicated close adherence to FDA content guidelines except for financial disclosures. Nonrepresentative cross-sectional surveys of self-selected prescribers suggested modestly greater ER/LA knowledge among CE completers than noncompleters, and claims-based surveillance indicated slowly declining ER/LA prescribing, although the contribution of the REMS to these trends could not be assessed. The effectiveness of the REMS program for reducing adverse outcomes also could not be assessed because the analyses used nonrepresentative samples, lacked adequate controls for confounding, and did not link prescribing or clinical outcomes to prescribers' receipt of CE training. Although the FDA had requested studies tracking adverse outcomes as a function of CE training, the FDA concluded that these studies had not been performed as of the 60-month report in 2017. Conclusions and Relevance: Five years after initiation, the FDA and ER/LA manufacturers could not conclude whether the ER/LA REMS had reduced inappropriate prescribing or improved patient outcomes. Alternative observational study designs would have allowed for more rigorous estimates of the program's effectiveness.

Assessment of the FDA Risk Evaluation and Mitigation Strategy for Transmucosal Immediate-Release Fentanyl Products.

IMPORTANCE: Transmucosal immediate-release fentanyls (TIRFs), indicated solely for breakthrough cancer pain in opioid-tolerant patients, are subject to a US Food and Drug Administration (FDA) Risk Evaluation and Mitigation Strategy (REMS) to prevent them from being prescribed inappropriately. OBJECTIVES: To evaluate knowledge assessments of pharmacists, prescribers, and patients regarding appropriate TIRF use; to describe sponsor assessments, based on claims data, of whether the REMS program was meeting its goals; and to characterize how the FDA responded to REMS assessments. DESIGN, SETTING, AND PARTICIPANTS: Qualitative analysis of 4877 pages of FDA documents obtained through a Freedom of Information Act request, including 6 annual REMS assessment reports (2012-2017), FDA evaluations of these reports, and FDA-sponsor correspondence about safety issues. EXPOSURE: A REMS program to reduce the risk of adverse outcomes, including misuse, abuse, addiction, and overdose, arising from use of TIRFs. MAIN OUTCOMES AND MEASURES: (1) Knowledge assessments of pharmacists, prescribers, and patients; (2) survey and claims-based prescribing assessments; (3) FDA and TIRF sponsor communications; (4) modifications to the REMS program; and (5) disenrollment of noncompliant prescribers. RESULTS: Twelve months after initiation of the program, 24 of 302 pharmacists (7.9%), 35 of 302 prescribers (11.6%), and 5 of 192 patients (2.6%) incorrectly reported that TIRFs can be prescribed to opioid-nontolerant patients, with similar levels of misunderstanding maintained in the subsequent reports. At 60 months, product-specific analyses of claims data indicated that between 34.6% and 55.4% of patients prescribed TIRFs were opioid-nontolerant. In the 48-month survey, 106 of 310 prescribers (34.2%) reported prescribing TIRFs for opioid-tolerant patients with chronic, noncancer pain; at 60 months, 54 of 302 prescribers (18.4%) and 148 of 310 patients (47.7%) erroneously reported that TIRFs were FDA-approved for such use. Over the 60-month period examined, there were few substantive changes made to the REMS to address evidence of high rates of off-label TIRF use, and, although the REMS program had a noncompliance plan, there was no report of prescribers being disenrolled for inappropriate prescribing. CONCLUSIONS AND RELEVANCE: In this review of FDA documents pertaining to the TIRF REMS, surveys of pharmacists, prescribers, and patients reflected generally high levels of knowledge regarding proper TIRF prescribing, yet some survey items as well as claims-based analyses indicated substantial rates of inappropriate TIRF use. Despite these findings, the FDA did not require substantive changes to the program.