Metformin Alkaloid-Int (Metformin Hydrochloride)

Metformin is a biguanide antidiabetic that acts on glucose metabolism.

• Type 2 diabetes mellitus: lowers fasting and post‑prandial blood glucose levels.
• Prediabetes: helps delay progression to overt diabetes by improving insulin sensitivity.
• Polycystic ovary syndrome: reduces insulin resistance and may improve menstrual regularity.

• Metformin primarily activates AMP‑activated protein kinase (AMPK) in liver and muscle cells, which suppresses gluconeogenesis and enhances peripheral glucose uptake. The drug also improves insulin receptor signaling and reduces intestinal glucose absorption, collectively contributing to lower plasma glucose concentrations without stimulating insulin secretion.

Metformin is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Gastrointestinal upset: nausea, abdominal discomfort, or loss of appetite.
• Diarrhea: loose stools that may be mild to moderate.
• Metallic taste: transient alteration in taste perception.

Serious or Rare Side Effects

• Lactic acidosis: a rare but potentially fatal accumulation of lactate.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Hepatic dysfunction: abnormal liver enzymes or hepatitis.
• Hypoglycemia: primarily when combined with other glucose‑lowering agents.
• Pancreatitis: inflammation of the pancreas reported in isolated cases.

Metformin requires careful monitoring in several clinical situations.

• Renal function: assess creatinine clearance before initiation and periodically thereafter.
• Hepatic function: evaluate liver enzymes to reduce risk of lactic acidosis.
• Risk of lactic acidosis: avoid in patients with conditions predisposing to hypoxia or metabolic acidosis.
• Elderly patients: start at lower doses and titrate slowly.
• Concomitant medications: review for drugs that may impair renal clearance.
• Store at ambient temperature: keep in the original container, protect from moisture and heat.

Metformin may interact with other medicines, necessitating vigilance.

Major Interactions (Avoid)

• Iodinated contrast agents: can precipitate acute renal failure and lactic acidosis.
• Cimetidine: may increase metformin plasma concentrations.
• Alcohol (excessive): raises risk of lactic acidosis.
• Carbamazepine: reduces metformin efficacy by increasing renal clearance.
• Rifampicin: induces hepatic enzymes, lowering metformin levels.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask hypoglycemia symptoms.
• Diuretics: can affect renal function and metformin clearance.
• ACE inhibitors: monitor renal function when combined.
• NSAIDs: may impair renal perfusion, increasing metformin exposure.
• Sulfonylureas: heightened risk of hypoglycemia when used together.