Metformin Teva B.V. (Metformin Hydrochloride)

Metformin Hydrochloride is a biguanide that acts on glucose metabolism to control hyperglycaemia in several related conditions.

• Type 2 diabetes mellitus: improves glycaemic control by reducing hepatic glucose output and enhancing peripheral insulin sensitivity.
• Prediabetes (impaired glucose tolerance): lowers the risk of progression to type 2 diabetes when used with lifestyle measures.
• Polycystic ovary syndrome: helps restore ovulatory function by decreasing insulin resistance and lowering circulating androgen levels.

• Metformin Hydrochloride penetrates hepatocytes and activates AMP‑activated protein kinase (AMPK), which suppresses gluconeogenic gene expression and reduces hepatic glucose production. It also enhances insulin‑mediated glucose uptake in skeletal muscle and adipose tissue, thereby improving peripheral insulin sensitivity and lowering circulating blood glucose levels.

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

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhoea: frequent loose stools, especially during treatment initiation.
• Abdominal discomfort: cramping or bloating.
• Metallic taste: transient alteration of taste perception.
• Loss of appetite: reduced desire to eat.
• Flatulence: increased intestinal gas.

Serious or Rare Side Effects

• Lactic acidosis: a rare but life‑threatening accumulation of lactate.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Hypoglycaemia: when combined with other glucose‑lowering agents.
• Anaemia: unexplained reduction in haemoglobin.
• Pancreatitis: inflammation of the pancreas.

Metformin Hydrochloride requires careful monitoring in specific patient groups and clinical situations.

• Renal function monitoring: assess creatinine clearance before initiation and periodically thereafter.
• Hepatic assessment: evaluate liver function tests prior to therapy.
• Lactic acidosis risk: avoid use in patients with conditions predisposing to hypoxia or severe infection.
• Elderly patients: start at lower doses and monitor tolerance closely.
• Alcohol consumption: limit intake to reduce lactic acidosis risk.
• Store at ambient temperature: keep in the original container, protect from moisture and heat.

Metformin Hydrochloride may interact with several medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Iodinated contrast agents: can precipitate acute renal failure and increase lactic acidosis risk.
• Cimetidine: may raise metformin plasma concentrations.
• Alcohol: potentiates lactic acidosis.
• Carbamazepine: reduces metformin exposure.
• Rifampicin: decreases metformin levels.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask hypoglycaemia symptoms.
• ACE inhibitors: can affect renal function, requiring dose adjustment.
• Diuretics: may impair renal clearance of metformin.
• NSAIDs: increase risk of renal impairment.
• Digoxin: monitor for additive effects on renal function.