Metformina Teva (Metformin Hydrochloride)

Metformin is an oral antidiabetic agent used in the management of type 2 diabetes mellitus.

• Type 2 diabetes mellitus: improves glycemic control by lowering fasting and post‑prandial glucose levels.
• Prediabetes (impaired fasting glucose or impaired glucose tolerance): helps delay progression to overt diabetes when combined with lifestyle measures.
• Polycystic ovary syndrome (off‑label): may improve insulin resistance and restore ovulatory function.

• Metformin primarily inhibits hepatic gluconeogenesis by activating AMP‑activated protein kinase (AMPK), which reduces glucose production. It also enhances peripheral glucose uptake in muscle and adipose tissue by increasing insulin‑mediated glucose transport, and modestly lowers intestinal absorption of glucose, collectively improving overall insulin sensitivity.

Metformin is associated with a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Gastrointestinal upset: nausea, abdominal discomfort, and loss of appetite.
• Diarrhea: frequent loose stools, especially during treatment initiation.
• Metallic taste: transient alteration of taste perception.
• Weight loss: modest reduction in body weight.
• Vitamin B12 deficiency: decreased absorption with long‑term use.
• Skin rash: mild erythema or pruritus.

Serious or Rare Side Effects

• Lactic acidosis: rare but potentially fatal metabolic disturbance.
• Severe hypoglycemia: when combined with insulin or sulfonylureas.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Pancreatitis: inflammation of the pancreas.
• Anaphylactic reaction: rare systemic allergic response.
• Blood dyscrasias: neutropenia or agranulocytosis.

Metformin requires careful monitoring and patient education to minimize risks.

• Renal function assessment: evaluate creatinine clearance before initiation and periodically.
• Lactic acidosis risk: avoid in patients with severe renal or hepatic impairment.
• Alcohol consumption: limit intake to reduce lactic acidosis potential.
• Elderly patients: start with lower doses and monitor tolerance.
• Heart failure: assess stability before prescribing.
• Store at room temperature: keep in the original container, protect from moisture and heat.

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

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.
• Nitrates: combined use may increase risk of hypotension.
• High‑dose vitamin B12 supplements: may interfere with absorption.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask hypoglycemia symptoms.
• Thiazide diuretics: can raise blood glucose levels.
• ACE inhibitors: monitor renal function.
• Corticosteroids: may reduce glycemic control.
• Oral contraceptives: may affect metformin metabolism.