Metformin 500 mg — Uses, Dosage, Side Effects Pakistan

What Is Metformin 500?

Metformin (brand name Glucophage) is the most commonly prescribed diabetes medicine in Pakistan. It belongs to the biguanide class and works in two main ways:

1. Reduces glucose production in the liver
2. Increases insulin sensitivity in body cells

What Is Metformin Used For?

1. Type 2 Diabetes (Most Common)

First-line treatment — the safest and most effective option. Over 90% of Type 2 diabetic patients in Pakistan begin with Metformin.

2. PCOS (Polycystic Ovary Syndrome)

Addresses insulin resistance, helps regulate periods, and reduces hirsutism. PCOS is very common in Pakistan — affecting 1 in 5 women.

3. Pre-Diabetes

HbA1c of 5.7–6.4% — used to prevent progression to full diabetes.

4. Gestational Diabetes

Used as an alternative or supplement to insulin during pregnancy.

5. Weight Management (Off-Label)

In obese patients with insulin resistance.

6. Anti-Aging Research

Studies suggest potential longevity benefits — further research ongoing.

Dosage

Type 2 Diabetes:

PCOS:

500 mg twice daily — allow a 4–6 month trial.

Slow Dose Titration Is Important:

Increase the dose gradually to minimise stomach upset. Starting at a high dose causes excessive side effects.

Side Effects

Common (10–30%, especially at the start):

• Loose stools / diarrhoea (most common)
• Nausea, vomiting
• Stomach pain, gas
• Metallic taste
• Loss of appetite (weight loss also possible)

Tip: These symptoms usually settle within 1–2 weeks. Taking with food helps significantly. The extended-release (XR) version has fewer side effects.

Long-Term Risks:

• Vitamin B12 deficiency — causing anaemia, fatigue, neuropathy. Check annually.
• Lactic acidosis (rare, serious) — muscle pain, rapid breathing, weakness

When to Avoid Metformin

• Severe kidney disease (eGFR < 30) — avoid completely
• Moderate kidney disease (eGFR 30–45) — reduce dose
• Severe heart failure
• Advanced liver disease
• Severe dehydration
• Surgery / IV contrast scan — hold temporarily
• Severe infections
• Alcoholism

B12 Deficiency Check

Long-term Metformin use (1+ year) reduces Vitamin B12 absorption. Check B12 levels once a year. Watch for symptoms:

• Fatigue
• Numbness or tingling in hands and feet
• Memory issues
• Anaemia (pallor, weakness)

Solution: Oral B12 supplement (1000 mcg daily) or monthly injection.

Drug Interactions

• IV contrast (for CT scans): Hold Metformin 48 hours before and after
• Alcohol: Increases lactic acidosis risk
• Diuretics: May affect kidney function
• Steroids: Raise blood sugar — reduce Metformin effectiveness
• Cimetidine, Trimethoprim: Increase Metformin levels

Pregnancy and Breastfeeding

• Pregnancy: Generally safe (Category B). Commonly used in gestational diabetes and PCOS pregnancies.
• Breastfeeding: Small amount passes to baby — generally considered safe.

Metformin XR (Extended Release)

Once-daily option with fewer side effects. Brands: Glucophage XR, Metsil XR. Slightly more expensive but better compliance.

Lifestyle Changes Are Essential

Metformin alone is not enough — these changes are necessary:

• Diet: Less white rice and roti; more vegetables and protein
• Exercise: 30-minute walk daily
• Weight loss: Even 5–10% weight reduction brings major improvement
• Regular monitoring: HbA1c every 3 months
• Foot care (for diabetic patients)

Common Misuse in Pakistan

• Taking on an empty stomach — causes excessive side effects
• Starting on a high dose immediately
• Not checking B12 levels
• Ignoring lifestyle changes
• Stopping when symptoms improve

Conclusion

Metformin is Pakistan's safest, most affordable and most effective first-line treatment for diabetes and PCOS. Start with food, increase the dose gradually, and check B12 annually. Medicine alone is not enough — diet and exercise are essential. Use Ilaaj AI to consult an endocrinologist, get dose adjustments, and monitor labs from home.