Formet 500 | 1 Strip

✔️ Dosage & Administration | Formet 500

Metformin Immediate Release (IR):

• Adults: Start with 500 mg twice daily or 850 mg once daily with meals. Gradually increase by 500 mg weekly or 850 mg every two weeks up to 2000 mg/day, divided into doses. If additional glycemic control is required, doses up to 2550 mg/day may be used.
• Children (≥10 years): Begin with 500 mg twice daily with meals; increase by 500 mg weekly to a maximum of 2000 mg/day, divided into doses.

Metformin Extended Release (XR):

• Adults: Start with 500 mg once daily with the evening meal. Gradually increase by 500 mg weekly up to 2000 mg once daily or 1000 mg twice daily. Swallow tablets whole—do not crush or chew.
• Children: XR formulation not recommended.

Renal Impairment:

Contraindicated if eGFR <30 mL/min/1.73 m².

Assess risk/benefit if eGFR <45 mL/min/1.73 m².

• Elderly: Adjust dose based on renal function; monitor frequently.
• Children (10–12 years): Prescribe with caution; closely monitor growth and puberty.
• Renal impairment: Assess GFR regularly — at least annually for normal function, and 2–4 times yearly for borderline or elderly patients.

✔️ Side Effects | Formet 500

Very Common: Gastrointestinal disturbances such as nausea, vomiting, diarrhea, abdominal discomfort, and loss of appetite (often transient and self-resolving).

Common: Taste disturbances.

Very Rare: Lactic acidosis, decreased Vitamin B12 absorption (may cause megaloblastic anemia), hepatic dysfunction, and skin reactions like erythema or urticaria.

Not Known: Encephalopathy, hemolytic anemia.

Gradual dose escalation and taking the medicine with meals help improve gastrointestinal tolerance.

✔️ Interactions

Enhanced absorption: Nifedipine may increase metformin absorption.

Renal competition: Cationic drugs (e.g., Digoxin, Morphine, Quinidine, Trimethoprim, Vancomycin) may compete for renal tubular secretion, potentially increasing plasma metformin levels.

Hyperglycemic agents: Drugs such as corticosteroids, diuretics, oral contraceptives, thyroid hormones, and calcium channel blockers may reduce glycemic control.

Cimetidine: May increase metformin concentration; use with caution.

✔️ Contraindications

• Hypersensitivity to metformin or any of its components
• Acute metabolic acidosis (e.g., lactic acidosis, diabetic ketoacidosis)
• Severe renal impairment (eGFR <30 mL/min/1.73 m²)
• Conditions predisposing to hypoxia: cardiac or respiratory failure, recent myocardial infarction, shock
• Severe hepatic insufficiency or chronic alcoholism

✔️ Pregnancy & Lactation

Pregnancy: Uncontrolled diabetes during pregnancy increases the risk of congenital defects and perinatal mortality. Insulin is preferred during pregnancy for optimal glucose control.

Lactation: Metformin is excreted in breast milk in small amounts. Although no adverse effects have been reported in infants, breastfeeding is generally not recommended during metformin therapy unless the benefits outweigh the potential risks.

✔️ Precautions & Warnings

• Renal monitoring: Regularly assess kidney function; discontinue if renal function declines.
• Vitamin B12 deficiency: Long-term use may lower Vitamin B12 levels; monitor annually.
• Surgery and investigations: Stop metformin 2–3 days before major surgery or radiological procedures involving iodinated contrast.
• Dehydration or infection: Avoid use during severe infection, dehydration, or trauma.
• Combination therapy: When used with insulin or sulfonylureas, monitor for hypoglycemia.

✔️ Storage:

Store below 30°C, protected from light and moisture.
Keep out of reach of children.