Metformin Medicine

Metformin Medicine 

1. Overview

Metformin is a first-line oral medication primarily used to manage type 2 diabetes mellitus. It is not used for type 1 diabetes. It works by improving glycemic control with a low risk of hypoglycemia and is often prescribed alongside lifestyle modifications.

2. Mechanism of Action 

-Reduces Hepatic Glucose Production:

 Inhibits gluconeogenesis in the liver.  

Enhances Insulin Sensitivity:

 Increases glucose uptake in muscle and adipose tissue.  

Delays Intestinal Glucose Absorption: Modestly affects absorption in the gut.  

3. Clinical Uses 

Type 2 Diabetes: First-line therapy to lower blood glucose.  

Off-Label: Polycystic ovary syndrome (PCOS) to improve insulin resistance and regulate menstrual cycles.  

4. Dosage Forms & Administration

Forms: Immediate-release (IR; 2–3 times daily) and extended-release (XR; once daily).  

Dosing:  

  Start: 500 mg once daily or 850 mg daily, titrated weekly.  

  Maintenance: 1500–2000 mg/day (IR) or 2000 mg/day (XR).  

  Max Dose: 2550 mg/day (IR) or 2000 mg/day (XR).  

Take with meals to minimize gastrointestinal (GI) side effects.

5. Side Effects  

Common:Nausea, diarrhea, abdominal discomfort (often transient; XR may reduce these).  

Rare but Serious: Lactic acidosis (symptoms: muscle pain, rapid breathing, fatigue).  

Long-Term: Vitamin B12 deficiency (monitor levels periodically).

6. Contraindications & Precautions

Absolute: Severe kidney impairment (eGFR <30 mL/min/1.73m²), metabolic acidosis, or hypersensitivity.  

Use with Caution: In hepatic impairment, acute illness (e.g., sepsis), or before iodinated contrast imaging (withhold 48 hours before/after if eGFR <60).  

7. Drug Interactions 

Nephrotoxic Drugs (e.g., NSAIDs, certain diuretics) may increase lactic acidosis risk.  

Cationic Drugs (e.g., ranitidine) may compete for renal excretion.  

8. Monitoring  

Kidney Function: eGFR at baseline and annually (avoid if eGFR <30).  

Vitamin B12: Check every 2–3 years with long-term use.  

Glycemic Control:Regular HbA1c testing.  

9. Special Populations

Pregnancy: Category B (safe in some guidelines but insulin is preferred for gestational diabetes).  

- Elderly: Monitor renal function closely.  

10. Recent Updates  

CKD Use:Now acceptable for eGFR ≥30 (previously restricted at eGFR <60).  

- Research: Investigational roles in aging and cancer, though not FDA-approved.  

Key Counseling Points  

- Take with food to reduce GI upset.  

- Report symptoms of lactic acidosis (e.g., unusual muscle pain, dizziness).  

- Avoid excessive alcohol intake (increases acidosis risk).  

Metformin remains a cornerstone in diabetes management due to its efficacy, safety, and cost-effectiveness. Always consult healthcare providers for personalized advice.