| Metformin | To discontinue on the day of surgery | Gastrointestinal discomfort and lactic acidosis should be avoided; Patients with stage 4 severe chronic kidney disease (CKD) [estimated glomerular filtration rate 30 mL·min-1·(1.73 m2)-1] are contraindicated |
| Sulfonylureas and meglitinides | To discontinue at the start of preoperative diet (i.e., 2‒4 weeks before surgery) | Hypoglycemia and weight gain should be avoided |
| Thiazolidinediones | To discontinue on the day of surgery | Weight gain, fluid retention, and edema should all be avoided |
| ɑ-glucosidase inhibitors | To discontinue on the day before metabolic surgery | Gastrointestinal side effects should be avoided |
| Dipeptidyl peptidase-4 (DPP-4) inhibitors | To discontinue on the day of surgery | Patients with heart failure, arthralgia, skin conditions, allergic reactions and acute pancreatitis should use it with caution |
| Sodium-glucose cotransporter-2 (SGLT2) inhibitors | To discontinue 3 d prior to surgery (2 weeks prior to surgery for those on a low-calorie ketogenic diet) | Genitourinary tract infections, hypotension, fractures, acute kidney injury, ketoacidosis, and rare cases of Fournier's gangrene should all be taken seriously |
| Glucagon-like peptide 1 (GLP-1) receptor agonists | To discontinue on the day of surgery | Gastrointestinal side effects should be avoided; Patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2 are contraindicated |