PEBC: What You Need to Know: Metformin
Updated: Jul 25, 2020
Type 2 diabetes. First line therapy as per Diabetes Canada guidelines. Cornerstone of treatment → combine with other diabetic medications for greater control
Start with low dose and slowly titrate over a few weeks. Divide into 2 to 3 doses per day for better GI tolerance.
Gastrointestinal upset: diarrhea, gas, bloating, abdominal discomfort → reduce adverse effects by taking with food and slow dose titration. Symptoms disappear after a few weeks.
Weight neutral to weight loss for some patients
Low risk of hypoglycemia as monotherapy. Reduces weight gain of other medications (insulin, sulfonylureas)
May reduce vitamin B12 levels
Lactic acidosis is rare
Do not use for creatinine clearance under 30 mL/min
Hold for 48 hours after contrast dye studies to avoid renal dysfunction