Take initially 1 tablet once daily with the evening meal, maximum dose 1500-2000 mg/day.
Type 2 diabetes management: Note: Allow 1-2 weeks between dose titrations: Generally, clinically significant responses are not seen at doses <1500 mg daily; however, a lower recommended starting dose and gradual increased dosage is recommended to minimize gastrointestinal symptoms.
Dosing adjustment/comments in renal impairment: The plasma and blood half-life of metformin is prolonged and the renal clearance is decreased in proportion to the decrease in creatinine clearance. Per the manufacturer, metformin is contraindicated in the presence of renal dysfunction defined as a serum creatinine 1.5 mg/dL in males, or ≥1.4 mg/dL in females and in patients with abnormal clearance. The Canadian labeling recommends that metformin be avoided in patients with Clcr <60 mL/minute.
Dosing adjustment in hepatic impairment: Avoid metformin; liver disease is a risk factor for the development of' lactic acidosis during metformin therapy.
Dietary Considerations: Drug may cause GI upset; take with food (to decrease GI upset). Take at the same time(s) each day. Dietary modification based on ADA recommendations is a part of therapy. Monitor for signs and symptoms of vitamin B12 and/or folic acid deficiency; supplementation may be required.
Administration: Administer with a meal (to decrease GI upset). Extended release: Swallow whole; do not crush, break, or chew. Administer once daily doses with the evening meal. Fortamet should also be administered with a full glass of water.