Tirzepatide, the Newest Medication for Type 2 Diabetes: A Review of the Literature and Implications for Clinical Practice

Objective: The objective of this article was to review pharmacology, efficacy, safety, and place in therapy of tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. Data Sources: PubMed/MEDLINE and ClinicalTrials.gov were searched through September 7, 2022, using the keyword “tirzepatide.” Study Selection and Data Extraction: Clinical trials with available results were included. Data Synthesis: Seven published phase 3, multicenter, randomized, parallel-group trials investigated efficacy and safety of tirzepatide versus placebo, semaglutide, insulin degludec, and insulin glargine for type 2 diabetes mellitus (T2DM) treatment. Studies included adults with uncontrolled T2DM and body mass index above 23 or 25 kg/m 2 . Hemoglobin A1c reduction from baseline was greater with tirzepatide across all studies with absolute reductions up to 3.02% and relative reductions ranging 0.44% (vs semaglutide) to 2.11% (vs placebo). Weight loss was significant. Incidence of gastrointestinal adverse effects (AE) was similar to semaglutide, and major cardiovascular events was similar to insulin glargine. Relevance to Patient Care and Clinical Practice: Studies demonstrated greater A1c lowering and weight reduction versus placebo and active comparators with AE similar to semaglutide, suggesting tirzepatide will be a valuable addition to the growing list of antidiabetic medications. Although tirzepatide’s effects on major cardiovascular events was not increased when compared with insulin glargine, further evidence is needed to assess long-term implications on cardiovascular outcomes compared with agents with proven cardiovascular benefits. Conclusions: Tirzepatide has the potential to significantly impact the clinical management of T2DM, and results of ongoing clinical trials will help to fully determine its place in therapy.