Mechanism of Action
Repaglinide works by binding to and closing ATP-dependent potassium channels in the beta cells of the pancreas. This action causes the cell membrane to depolarize, leading to the opening of calcium channels. The resulting influx of calcium induces the secretion of insulin.
Indications
Repaglinide is indicated for the management of type 2 diabetes mellitus in conjunction with diet and exercise. It is often used when other medications, such as metformin, are not sufficient to control blood sugar levels.
Dosage and Administration
- Initial Dose: Typically, 0.5 mg before each meal.
- Maintenance Dose: The dose may be adjusted based on blood glucose response, usually ranging from 0.5 mg to 4 mg taken before meals.
- Administration: It should be taken 15 to 30 minutes before meals. If a meal is skipped, the dose should also be skipped to avoid hypoglycemia.
Side Effects
Common Side Effects:
- Hypoglycemia (low blood sugar)
- Weight gain
- Upper respiratory tract infections
- Headache
- Back pain
Serious Side Effects (Rare):
- Severe hypoglycemia leading to confusion or seizures.
- Liver dysfunction in patients with hepatic impairment.
Contraindications
Repaglinide is contraindicated in patients with:
- Type 1 diabetes mellitus
- Diabetic ketoacidosis
- Severe liver or kidney impairment
- Known hypersensitivity to repaglinide or any of its components
Drug Interactions
- CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): Can increase repaglinide levels, raising the risk of hypoglycemia.
- CYP3A4 inducers (e.g., rifampin): Can decrease repaglinide levels, reducing its efficacy.
- Beta-blockers: Can mask the symptoms of hypoglycemia.
- NSAIDs and other highly protein-bound drugs: Can displace repaglinide from plasma proteins, increasing its effects.
Monitoring Guidelines
- Patients taking repaglinide should regularly monitor their blood glucose levels to ensure they are within the target range and to adjust the dose as necessary.
- Regular HbA1c testing is also recommended to assess long-term glycemic control.
Special Populations
- Elderly: Higher risk of hypoglycemia; careful dose adjustment required.
- Pregnancy and Breastfeeding: Use only if benefits outweigh risks.
- Liver and Kidney Impairment: Use cautiously with close monitoring.
Conclusion
Repaglinide is a fast-acting and effective treatment for type 2 diabetes, especially for controlling post-meal blood sugar spikes. However, proper dosing and monitoring are crucial to minimize hypoglycemia and side effects. Always seek advice from your healthcare provider for tailored medical guidance.