Metformin Sandoz (Metformin Hydrochloride)

Metformin is indicated for conditions involving impaired glucose metabolism and insulin resistance.

• Type 2 diabetes mellitus: improves glycemic control and reduces HbA1c levels.
• Prediabetes (impaired glucose tolerance): helps delay progression to overt diabetes.
• Polycystic ovary syndrome: may improve insulin sensitivity and restore ovulatory function.

• Metformin primarily inhibits hepatic gluconeogenesis, decreasing glucose output from the liver. It also enhances peripheral glucose uptake by increasing insulin‑mediated activation of AMP‑activated protein kinase (AMPK), which improves insulin sensitivity in muscle and adipose tissue, leading to lower circulating blood glucose levels.

Metformin is generally well tolerated, but several adverse reactions have been reported.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Diarrhea: frequent loose stools, especially during dose titration.
• Abdominal discomfort: cramping or bloating.
• Metallic taste: transient alteration of taste perception.
• Loss of appetite: reduced desire to eat.
• Vitamin B12 deficiency: decreased absorption with long‑term use.

Serious or Rare Side Effects

• Lactic acidosis: rare but life‑threatening metabolic acidosis.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Hepatic dysfunction: marked elevation of liver enzymes.
• Pancreatitis: inflammation of the pancreas.
• Hypoglycemia: when combined with other glucose‑lowering agents.
• Anemia: due to reduced red blood cell production.

Metformin should be used with careful clinical monitoring and patient education.

• Renal function: assess eGFR before initiating and periodically thereafter.
• Hepatic disease: avoid in patients with severe liver impairment.
• Alcohol consumption: limit intake to reduce risk of lactic acidosis.
• Pregnancy: discuss risks and benefits with the prescriber; use only if clearly needed.
• Elderly patients: monitor renal function closely due to age‑related decline.
• Store at ambient temperature: keep in the original container, protect from moisture and heat.

Metformin may interact with several medicines, requiring dose adjustment or monitoring.

Major Interactions (Avoid)

• Iodinated contrast agents: increase risk of renal impairment and lactic acidosis.
• Cimetidine: can raise metformin plasma concentrations.
• Alcohol: potentiates lactic acidosis risk.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask symptoms of hypoglycemia.
• Diuretics (especially thiazides): affect renal clearance of metformin.
• ACE inhibitors or ARBs: require monitoring of renal function and electrolytes.