1. Clinical Overview
A fixed-dose combination (FDC) oral anti-diabetic drug containing a sulfonylurea (Glimepiride) and a biguanide (Metformin). It is a second-line therapy for the management of type 2 diabetes mellitus (T2DM) in adults when diet, exercise, and monotherapy with either metformin or a sulfonylurea do not result in adequate glycemic control. It addresses both insulin resistance and insulin secretion deficiency.
| Onset | Duration | Bioavailability |
|---|---|---|
| Glimepiride: 1-2 hours; Metformin: 1-2 hours (glucose-lowering effect). | Glimepiride: Up to 24 hours; Metformin: 8-12 hours. | Glimepiride: ~100%; Metformin: 50-60%. |
2. Mechanism of Action
This combination provides a dual mechanism: Glimepiride stimulates insulin release from pancreatic beta cells and may increase peripheral tissue sensitivity to insulin. Metformin decreases hepatic glucose production (gluconeogenesis), decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization.
3. Indications & Uses
- Type 2 Diabetes Mellitus in adults, as an adjunct to diet and exercise, when dual therapy is appropriate.
4. Dosage & Administration
Adult Dosage: One tablet of Glimepiride (2mg) + Metformin (500mg) once or twice daily with meals. The dose must be individualized based on efficacy and tolerability. Maximum recommended daily dose: Glimepiride 8mg + Metformin 2000mg.
Administration: Should be taken with or immediately after the main meals (breakfast and/or dinner) to reduce gastrointestinal side effects of metformin and minimize risk of hypoglycemia. Tablet should be swallowed whole with a glass of water; do not crush or chew.
5. Side Effects
Common side effects may include:
- Hypoglycemia (tremor, sweating, anxiety, palpitations)
- Gastrointestinal: Nausea, vomiting, diarrhea, abdominal pain, flatulence, metallic taste (primarily metformin-related, often transient)
- Headache
- Dizziness
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Other Anti-diabetics (Insulin, DPP-4 inhibitors, SGLT2 inhibitors, etc.) | Increased risk of hypoglycemia. | Major |
| Beta-blockers (e.g., Propranolol) | May mask tachycardia (warning signs) of hypoglycemia and potentiate hypoglycemic effect. | Moderate |
| Alcohol | Acute: Potentiates hypoglycemic effect of glimepiride. Chronic: Increases risk of lactic acidosis with metformin. | Major |
| Warfarin | Glimepiride may potentiate anticoagulant effect; monitor INR. | Moderate |
| CYP2C9 Inhibitors (e.g., Fluconazole, Amiodarone) | Increase glimepiride plasma levels, risk of hypoglycemia. | Moderate |
| CYP2C9 Inducers (e.g., Rifampicin) | Decrease glimepiride plasma levels, reducing efficacy. | Moderate |
| Cationic Drugs (e.g., Cimetidine, Ranitidine, Digoxin, Morphine, Vancomycin) | Competitively inhibit renal tubular secretion of metformin, potentially increasing its plasma levels. | Moderate |
| Diuretics (especially Thiazides and Loop diuretics) | May cause hyperglycemia, reducing efficacy. Also risk of lactic acidosis with metformin in setting of dehydration. | Moderate |
| Corticosteroids (e.g., Prednisolone) | Cause hyperglycemia, reducing anti-diabetic efficacy. | Moderate |
| Iodinated Contrast Media | Risk of lactic acidosis and acute renal failure. Metformin must be withheld before and after the procedure as per guidelines. | Major |
7. Patient Counselling
- DO take the tablet with or immediately after meals.
- DO monitor your blood glucose levels regularly as advised by your doctor.
- DO carry a quick source of sugar (glucose tablets, candy) at all times to treat mild hypoglycemia.
- DO inform all your doctors and dentists that you are taking this medicine.
- DO get your kidney function tested at least once a year.
- DO report any unexplained muscle pain, breathing difficulty, or extreme tiredness immediately.
- DONT skip meals while on this medication.
- DONT consume alcohol.
- DONT take the medicine if you are planning a procedure with contrast dye or have severe vomiting/diarrhea - contact your doctor.
- DONT share your medicine with others.
8. Toxicology & Storage
Overdose: Primarily manifests as severe, prolonged hypoglycemia (sweating, tremor, tachycardia, anxiety, hunger, confusion, drowsiness, visual disturbances, coma, seizures). Symptoms of metformin overdose may include lactic acidosis (non-specific: malaise, myalgia, respiratory distress, abdominal pain, hypothermia, hypotension, bradycardia).
Storage: Store below 30°C. Protect from light and moisture. Keep the container tightly closed. Keep out of reach and sight of children. Do not use after the expiry date printed on the pack.