Metformin instructions for administration

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Instructions For Administration

GLUCOPHAGE

GLUCOPHAGE XR

Switching from GLUCOPHAGE to GLUCOPHAGE XR

Transfer From Other Antidiabetic Therapy

Concomitant GLUCOPHAGE or GLUCOPHAGE XR and Oral Sulfonylurea Therapy

Concomitant GLUCOPHAGE or GLUCOPHAGE XR and Insulin Therapy

Specific Patient Populations

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GLUCOPHAGE

The usual starting dose of GLUCOPHAGE (metformin hydrochloride tablets) is 500 mg twice a day or 850 mg once a day, given with meals. Dosage increases should be made in increments of 500 mg weekly or 850 mg every 2 weeks, up to a total of 2000 mg per day, given in divided doses. Patients can also be titrated from 500 mg twice a day to 850 mg twice a day after 2 weeks. For those patients requiring additional glycemic control, GLUCOPHAGE may be given to a maximum daily dose of 2550 mg per day. Doses above 2000 mg may be better tolerated given three times a day with meals. Return to top

GLUCOPHAGE XR

The usual starting dose of GLUCOPHAGE XR (metformin hydrochloride extendedrelease tablets) is 500 mg once daily with the evening meal. Dosage increases should be made in increments of 500 mg weekly, up to a maximum of 2000 mg once daily with the evening meal. If glycemic control is not achieved on GLUCOPHAGE XR 2000 mg once daily, a trial of GLUCOPHAGE XR 1000 mg twice daily should be considered. If higher doses of metformin are required, GLUCOPHAGE should be used at total daily doses up to 2550 mg administered in divided daily doses, as described above. Return to top

Switching from GLUCOPHAGE to GLUCOPHAGE XR

In a randomized trial, patients currently treated with GLUCOPHAGE were switched to GLUCOPHAGE XR. Results of this trial suggest that patients receiving GLUCOPHAGE treatment may be safely switched to GLUCOPHAGE XR once daily at the same total daily dose, up to 2000 mg once daily. Following a switch from GLUCOPHAGE to GLUCOPHAGE XR, glycemic control should be closely monitored and dosage adjustments made accordingly. Return to top

Transfer From Other Antidiabetic Therapy

When transferring patients from standard oral hypoglycemic agents other than chlorpropamide to GLUCOPHAGE or GLUCOPHAGE XR, no transition period generally is necessary. When transferring patients from chlorpropamide, care should be exercised during the first two weeks because of the prolonged retention of chlorpropamide in the body, leading to overlapping drug effects and possible hypoglycemia. Return to top

Concomitant GLUCOPHAGE or GLUCOPHAGE XR and Oral Sulfonylurea Therapy

If patients have not responded to four weeks of the maximum dose of GLUCOPHAGE or GLUCOPHAGE XR monotherapy, consideration should be given to gradual addition of an oral sulfonylurea while continuing GLUCOPHAGE or GLUCOPHAGE XR at the maximum dose, even if prior primary or secondary failure to a sulfonylurea has occurred. Clinical and pharmacokinetic drug-drug interaction data are currently available only for metformin plus glyburide (glibenclamide).If patients have not satisfactorily responded to one to three months of concomitant therapy with the maximum dose of GLUCOPHAGE or GLUCOPHAGE XR and the maximum dose of an oral sulfonylurea, consider therapeutic alternatives including switching to insulin with or without GLUCOPHAGE or GLUCOPHAGE XR. Return to top

Concomitant GLUCOPHAGE or GLUCOPHAGE XR and Insulin Therapy

The current insulin dose should be continued upon initiation of GLUCOPHAGE or GLUCOPHAGE XR therapy. GLUCOPHAGE or GLUCOPHAGE XR therapy should be initiated at 500 mg once daily in patients on insulin therapy. For patients not responding adequately, the dose of GLUCOPHAGE or GLUCOPHAGE XR should be increased by 500 mg after approximately 1 week and by 500 mg every week thereafter until adequate glycemic control is achieved. The maximum recommended daily dose is 2500 mg for GLUCOPHAGE and 2000 mg for GLUCOPHAGE XR. It is recommended that the insulin dose be decreased by 10% to 25% when fasting plasma glucose concentrations decrease to less than 120 mg/dL in patients receiving concomitant insulin and GLUCOPHAGE or GLUCOPHAGE XR. Further adjustment should be individualized based on glucose-lowering response. Return to top

Specific Patient Populations

GLUCOPHAGE or GLUCOPHAGE XR are not recommended for use in pregnancy or for use in pediatric patients. The initial and maintenance dosing of GLUCOPHAGE or GLUCOPHAGE XR should be conservative in patients with advanced age, due to the potential for decreased renal function in this population. Any dosage adjustment should be based on a careful assessment of renal function. Generally, elderly, debilitated, and malnourished patients should not be titrated to the maximum dose of GLUCOPHAGE or GLUCOPHAGE XR. Monitoring of renal function is necessary to aid in prevention of lactic acidosis, particularly in the elderly. Return to top

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Adapted from the FDA Package Insert.