PEBC: What You Need to Know: Metformin

Indication:

Type 2 diabetes. First line therapy as per Diabetes Canada guidelines. Cornerstone of treatment → combine with other diabetic medications for greater control

Dosing:

Start with low dose and slowly titrate over a few weeks. Divide into 2 to 3 doses per day for better GI tolerance.

Adverse Effects:

• 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