Medication Overview

Glucophage, generically known as metformin, is an oral medication primarily used to manage type 2 diabetes. It belongs to the class of drugs known as biguanides. It helps control blood sugar levels by reducing glucose production in the liver and improving insulin sensitivity in muscle tissues.

Pharmacological Properties

Glucophage has a half-life of approximately 6 hours, making it suitable for dosing multiple times per day. It is not metabolized in the liver, and its excretion is primarily renal. Bioavailability is around 50-60%, and it reaches peak plasma concentration in about 2.5 hours after oral administration.

Approved Indications

Glucophage is approved for the management of type 2 diabetes mellitus, particularly in patients who do not achieve adequate glycemic control with diet and exercise alone. It may also be used in combination with other antidiabetic agents, such as sulfonylureas or insulin.

Dosage Forms

Glucophage is available in immediate-release tablets of 500 mg, 850 mg, and 1000 mg. Extended-release formulations are also available in 500 mg, 750 mg, and 1000 mg dosages. The tablets should be swallowed whole with meals to minimize gastrointestinal side effects.

Initial Dosing

For adult patients, the initial dose of Glucophage typically starts at 500 mg twice daily or 850 mg once daily, administered with meals. The dose can be gradually increased by the treating physician based on patient tolerance and glycemic response.

Dosage Adjustments

For patients with renal or hepatic impairment, dosage adjustments are necessary. Regular monitoring of renal function is recommended, and dosing should be individualized to achieve optimal glycemic control. The maximum daily dose should not exceed 2550 mg for immediate-release and 2000 mg for extended-release forms.

Administration Guidelines

Glucophage should be taken during or after meals to enhance absorption and reduce gastrointestinal side effects. The tablet must not be crushed or chewed. Extended-release forms should be taken once daily, preferably with the evening meal.

Mechanism of Action

Glucophage works by decreasing hepatic glucose production, decreasing intestinal absorption of glucose, and improving insulin sensitivity by increasing peripheral glucose uptake and utilization. These mechanisms help reduce fasting and postprandial blood glucose levels.

Clinical Use

Patients on Glucophage should regularly monitor their blood glucose levels to assess the medication’s efficacy. It is pivotal to complement medication with lifestyle modifications, including a balanced diet and regular physical activity, for optimal management of type 2 diabetes.

Drug Interactions

Concomitant use of certain medications like cimetidine, diuretics, and corticosteroids can affect the efficacy and safety of Glucophage. Alcohol intake should be limited as it increases the risk of lactic acidosis. Close monitoring is required when initiating or discontinuing concomitant medications.

Pharmacodynamic Effects

Glucophage reduces HbA1c levels by 1-2%, indicating significant glycemic control. It does not usually cause hypoglycemia when used as monotherapy. Additionally, some patients may experience weight loss as a secondary benefit, likely due to improved glucose metabolism.

Adverse Effects

Common adverse effects include gastrointestinal symptoms such as nausea, diarrhea, and abdominal discomfort. These symptoms are usually transient and reduce over time. Sustained-release formulations may result in fewer gastrointestinal side effects.

Monitoring Parameters

Patients on Glucophage should have periodic assessments of renal function, liver enzymes, and hematologic parameters. Monitoring of Vitamin B12 levels is recommended as long-term use can lead to vitamin B12 deficiency. Regular follow-up with a healthcare provider is essential for ongoing evaluation and dose adjustment.

Patient Counseling

Patients should be informed about the importance of adherence to prescribed dosing schedules and the necessity of lifestyle interventions. They should be advised to report any unusual symptoms, particularly gastrointestinal distress or signs indicative of lactic acidosis, to their healthcare provider immediately.

Storage Instructions

Glucophage tablets should be stored at room temperature, away from excessive heat and moisture. The medication should be kept out of reach of children. Specific storage conditions for extended-release formulations should be followed as indicated by the manufacturer.

Special Populations

The use of Glucophage in pregnant or lactating women should be carefully considered and only prescribed if clearly needed. In elderly patients, renal function should be regularly monitored due to increased risk of renal impairment. Pediatric use is approved for children 10 years and older but must be closely supervised by a pediatric endocrinologist or specialist.