FORTAMET, used as a once-per-day monotherapy, is indicated as an adjunct to diet and exercise to lower blood glucose. FORTAMET can be used concomitantly with a sulfonylurea or insulin to improve glycemic control in adults. FORTAMET is indicated in patients 17 years of age or older as either monotherapy or in combination therapy.
There is a black box warning associated with metformin products. Lactic acidosis due to metformin accumulation during treatment with FORTAMET is a rare but potentially fatal occurrence. Lactic acidosis may also occur in association with a number of pathophysiologic conditions and whenever there is significant tissue hypoperfusion and hypoxemia. Patients with congestive heart failure requiring pharmacologic management, in particular those with unstable or acute congestive heart failure who are at risk of hypoperfusion and hypoxemia, are at increased risk of lactic acidosis. The onset of lactic acidosis often is subtle, and can be accompanied only by nonspecific symptoms. The patient and the patient's physician must be aware of the possible importance of such symptoms and the patient should be instructed to notify the physician immediately if they occur. The risk of lactic acidosis increases with the degree of renal dysfunction and the patient's age. Treatment should not be initiated in patients ≥ 80 years of age unless renal function is not reduced. The risk of lactic acidosis while on FORTAMET therapy may be significantly decreased by: Initial and regular monitoring of renal and liver function; using the minimum effective dose of FORTAMET; promptly withholding FORTAMET in the presence of any condition associated with hypoxemia, dehydration, or sepsis; avoidance of FORTAMET in patients with hepatic disease; cautioning patients against excessive alcohol intake, either acute or chronic; and temporarily discontinuing FORTAMET prior to any intravascular radiocontrast study or surgical procedure. Lactic acidosis is a medical emergency requiring immediate discontinuation of FORTAMET and prompt institution of general supportive measures. Because metformin is dialyzable, prompt hemodialysis is recommended to correct the acidosis and remove the accumulated metformin.
FORTAMET is contraindicated in patients with renal disease or renal dysfunction (e.g., as suggested by serum creatinine levels of ≥ 1.5 mg/dL in males, ≥ 1.4 mg/dL in females, or abnormal creatinine clearance), congestive heart failure, known hypersensitivity to metformin, acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma.
FORTAMET should be temporarily discontinued in patients undergoing radiologic studies involving intravascular administration of iodinated contrast materials, because use of such products may result in acute alteration of renal function.
In pooled phase II and III studies (N=424), the most frequent adverse events associated with FORTAMET were infection (20.5%), diarrhea (16.7%), nausea (8.5%), accidental injury (7.3%), dyspepsia (4.2%), and rhinitis (4.2%). In controlled studies, 4.7% of patients treated with FORTAMET (N=424) were discontinued as a result of an adverse event.
FORTAMET should be avoided in patients with impaired hepatic function or excessive alcohol intake (chronic or acute). In elderly patients, particularly those ≥80 years of age, renal function should be monitored regularly and, generally, FORTAMET should not be titrated to the maximum dose. FORTAMET should be withheld in the presence of any condition associated with hypoxia, dehydration, or sepsis.
FORTAMET alone does not usually cause hypoglycemia, although it may occur when FORTAMET is used in conjunction with oral sulfonylureas and/or insulin. When initiating combination therapy, the risks, symptoms, and treatment of hypoglycemia, as well as conditions that predispose its development, should be explained to patients and responsible family members.
The safety and efficacy of FORTAMET has not been evaluated in pediatric patients or pregnant women.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.FDA.gov/medwatch or call 1-800-FDA-1088
1. Fortamet® (metformin hydrochloride) extended-release tablets Prescribing Information. Atlanta, GA: Shionogi Inc.; May 2009. 2. Nathan DM, Buse JB, Davidson MB, et al. Medical management of hyperglycemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy: a consensus statement of the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care. 2009;32:193-203. 3. Bailey CJ. Metformin: a multitasking medication. Diab Vasc Dis Res. 2008;5:156. 4. Schwartz SL, Wu JF, Berner B. Metformin extended release for the treatment of type 2 diabetes mellitus. Expert Opin Pharmacother. 2006;7:803-809.