27/11/2025
*Metformin –
🔍 What It Is
- *Class:* Biguanide oral antidiabetic.
- *Main Use:* First-line treatment for *type 2 diabetes* (lowers blood glucose).
- *Other Uses:* PCOS (off-label), gestational diabetes, sometimes weight management.
# # # ⚙️ How It Works
1. *Decreases liver glucose production* (main effect).
2. *Improves insulin sensitivity* in muscle and fat.
3. *Reduces intestinal glucose absorption* (minor).
_Doesn’t cause hypoglycemia when used alone._
# # # 💊 Dosage Forms
- *Immediate-release (IR):* 500 mg, 850 mg, 1000 mg tabs.
- *Extended-release (XR/ER):* 500 mg, 750 mg, 1000 mg tabs.
- *Liquid:* 500 mg/5 mL (rare).
# # # 📝 Typical Dosing
| Situation | Starting Dose | Titration | Max Dose |
| Type 2 Diabetes (IR) | 500 mg once or twice daily (with meals) | ↑ by 500 mg weekly | 2000–2550 mg/day (split doses) |
| Type 2 Diabetes (XR) | 500–1000 mg once daily (with evening meal) | ↑ by 500 mg weekly | 2000 mg/day |
| PCOS (off-label) | 500 mg once daily | ↑ to 1500–2000 mg/day | 2000 mg/day |
_Always follow doctor’s plan – they adjust based on response/kidney function._
# # # ⏳ Pharmacokinetics
- *Absorption:* ~60% (food slows it a bit).
- *Half-life:* ~6.2 hrs (longer in kidney issues).
- *Excretion:* Unchanged in urine (no liver metabolism).
# # # ✅ Benefits
- *Effective A1C reduction* (1–2%).
- *Weight neutral or mild loss* (unlike many other diabetes meds).
- *Cardioprotective* (possible lower risk of heart events).
- *Low hypoglycemia risk* (when used alone).
# # # ⚠️ Side Effects
*Common (mild):*
- *GI upset:* nausea, diarrhea, abdominal pain, metallic taste.
- *B12 deficiency* (long-term).
*Rare but serious:*
- *Lactic acidosis* (dangerous if renal failure, dehydration, excess alcohol).
- *Hypoglycemia* (if combined with insulin/insulin secretagogues).
# # # 🚫 Contraindications
- *Renal impairment* (eGFR
