COMET XR 500 MG

Description

Indications

Comet XR tablets are indicated for managing type 2 diabetes mellitus, particularly in overweight patients, when dietary management and exercise alone fail to provide adequate glycemic control.

• In adults: Comet XR can be used as monotherapy or in combination with other oral antidiabetic agents or insulin.

• In children (10 years and above) and adolescents: Comet XR can be used as monotherapy or in combination with insulin.

Studies have demonstrated a reduction in diabetic complications in overweight adult patients with type 2 diabetes treated with metformin as a first-line therapy after dietary management failure.
(Take this medication only under the guidance of a registered physician.)

Pharmacology

Metformin, the active ingredient in Comet XR, belongs to the biguanide class of oral antihyperglycemic drugs. It helps manage type 2 diabetes by lowering both basal and postprandial plasma glucose levels. Unlike sulfonylureas, metformin does not stimulate insulin secretion or cause hypoglycemia.

Mechanism of Action:

1. Decreases hepatic glucose production.

2. Reduces intestinal absorption of glucose.

3. Improves insulin sensitivity by increasing peripheral glucose uptake and utilization.

Dosage & Administration

The dosage of metformin should be individualized based on effectiveness and patient tolerance.

Metformin Immediate-Release Tablets:

• Adults:

  • Starting dose: 500 mg twice daily or 850 mg once daily with meals.

  • Dose adjustments: Increase by 500 mg weekly or 850 mg every two weeks, up to a maximum of 2000 mg per day (divided doses).

  • For additional glycemic control, doses up to 2550 mg per day may be administered, preferably divided into three doses with meals.

• Children:

  • Starting dose: 500 mg twice daily with meals.

  • Dose adjustments: Increase by 500 mg weekly, up to a maximum of 2000 mg per day in divided doses.

Metformin Extended-Release Tablets:

• Adults:

  • Starting dose: 500 mg once daily with the evening meal.

  • Dose adjustments: Increase by 500 mg weekly, up to 2000 mg once daily with the evening meal, or 1000 mg twice daily with meals.

  • Patients switching from immediate-release tablets may transition to extended-release tablets up to the recommended maximum dose.

• Children: Not studied for extended-release formulations.

• Renal Impairment:

  • Do not use if eGFR <30 mL/min/1.73 m².

  • Evaluate risks if eGFR is between 30–45 mL/min/1.73 m².

(Take this medication only under the guidance of a registered physician.)

Interaction

• Co-administration with furosemide has no long-term interaction data.

• Nifedipine enhances metformin absorption but has minimal reciprocal effects.

• Cationic drugs (e.g., amiloride, digoxin, quinidine, vancomycin) may compete for renal tubular secretion, potentially causing interactions.

• Cimetidine may require dose adjustment due to altered metformin clearance.

• Medications like corticosteroids, estrogens, and diuretics may induce hyperglycemia and affect glycemic control.

Contraindications

• Hypersensitivity to metformin or any excipient.

• Acute metabolic acidosis (e.g., lactic acidosis, diabetic ketoacidosis).

• Severe renal impairment (eGFR <30 mL/min/1.73 m²).

• Acute conditions that could alter renal function (e.g., dehydration, severe infection, shock).

• Conditions causing tissue hypoxia (e.g., cardiac or respiratory failure, recent myocardial infarction).

• Chronic alcoholism or acute alcohol intoxication.

Side Effects

• Blood and Lymphatic System Disorders: Rare – Hemolytic anemia.

• Metabolism and Nutrition: Rare – Lactic acidosis, reduced vitamin B12 absorption, megaloblastic anemia.

• Nervous System: Common – Taste disturbances. Rare – Encephalopathy.

• Gastrointestinal Disorders: Common – Nausea, vomiting, diarrhea, abdominal pain, loss of appetite (especially during initiation).

• Hepatobiliary: Rare – Abnormal liver function or hepatitis.

• Skin Disorders: Rare – Rash, itching, hives.

Pregnancy & Lactation

• Pregnancy: Uncontrolled diabetes during pregnancy increases the risk of congenital abnormalities. Insulin is preferred during pregnancy to achieve near-normal blood glucose levels.

• Breastfeeding: Metformin is excreted into breast milk. While adverse effects in infants are rare, breastfeeding is generally not recommended during metformin treatment.

Precautions & Warnings

• Regularly monitor renal function as metformin is excreted by the kidney.

• Discontinue metformin 2–3 days before surgery or diagnostic tests requiring iodinated contrast media.

• Long-term use may reduce vitamin B12 levels; annual monitoring is recommended.

• Exercise caution when combined with insulin or sulfonylureas due to hypoglycemia risk.

Use in Special Populations

• Elderly: Adjust dose based on renal function; monitor renal health regularly.

• Children (10–12 years): Use cautiously, with close monitoring of growth and development.

Overdose Effects

Overdose may lead to lactic acidosis, a medical emergency requiring hospital treatment. Hemodialysis effectively removes lactate and metformin.

Therapeutic Class

Biguanides

Storage Conditions

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