Metformin Zentiva (Metformin Hydrochloride)

Metformin Zentiva is an oral biguanide indicated for disorders of glucose metabolism.

• Type 2 diabetes mellitus: lowers fasting and post‑prandial blood glucose levels.
• Prediabetes (impaired glucose tolerance): helps delay progression to overt diabetes.
• Polycystic ovary syndrome (insulin resistance): improves metabolic parameters associated with insulin resistance.

• Metformin reduces hepatic gluconeogenesis, decreases intestinal absorption of glucose, and enhances peripheral insulin sensitivity by activating AMP‑activated protein kinase (AMPK). These actions collectively lower circulating glucose without stimulating insulin secretion, helping to maintain glycaemic control in patients with type 2 diabetes.

Metformin may cause a range of adverse reactions, most of which are related to the gastrointestinal tract, while rare events can be serious.

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Diarrhea: frequent loose stools.
• Abdominal discomfort: cramping or pain.
• Metallic taste: transient alteration of taste.
• Weight loss: modest reduction in body weight.
• Vitamin B12 deficiency: decreased absorption over long‑term use.

Serious or Rare Side Effects

• Lactic acidosis: life‑threatening accumulation of lactate.
• Severe skin reactions: such as Stevens‑Johnson syndrome.
• Hepatic failure: impaired liver function.
• Hypoglycaemia: when combined with other glucose‑lowering agents.
• Acute pancreatitis: inflammation of the pancreas.
• Anemia: due to reduced red blood cell production.

Metformin should be used with careful clinical monitoring to minimise risks.

• Renal function assessment: evaluate creatinine clearance before initiation and periodically thereafter.
• Hepatic function monitoring: avoid use in patients with significant liver disease.
• Lactic acidosis risk: discontinue before any radiographic contrast procedures.
• Elderly patients: start at lower dose and titrate slowly.
• Alcohol consumption: limit intake to reduce lactic acidosis risk.
• Store at room temperature: keep in the original container, protect from moisture and heat.

Metformin interacts with several medicines that can alter its efficacy or safety.

Major Interactions (Avoid)

• Iodinated contrast agents: increase risk of lactic acidosis.
• Cimetidine: may raise metformin plasma concentrations.
• Alcohol: potentiates lactic acidosis.
• Carbamazepine: reduces metformin effectiveness.
• Rifampin: decreases metformin plasma levels.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask hypoglycaemia symptoms.
• Thiazide diuretics: can affect renal clearance.
• ACE inhibitors: monitor renal function.
• NSAIDs: may impair renal excretion.
• Digoxin: watch for altered plasma levels.