Metformina Vir (Metformin Hydrochloride)

Metformina Vir belongs to the biguanide class and is indicated for disorders of glucose metabolism.

• Type 2 diabetes mellitus: improves glycaemic control by reducing hepatic glucose output and increasing peripheral insulin sensitivity.
• Prediabetes: helps lower fasting plasma glucose and delays progression to overt diabetes.
• Polycystic ovary syndrome (off‑label): reduces insulin resistance and may improve menstrual regularity.

• Metformin primarily inhibits mitochondrial respiratory‑chain complex I, decreasing hepatic gluconeogenesis and increasing peripheral glucose uptake. It also enhances insulin receptor tyrosine kinase activity, leading to improved insulin sensitivity in muscle and adipose tissue, while modestly reducing intestinal glucose absorption.

Metformina Vir may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Gastrointestinal upset: nausea, abdominal discomfort, or loss of appetite.
• Diarrhoea: watery stools occurring especially during treatment initiation.
• Metallic taste: transient alteration of taste perception.
• Weight loss: modest reduction in body weight observed in some patients.

Serious or Rare Side Effects

• Lactic acidosis: a rare but potentially fatal accumulation of lactate, particularly in patients with renal impairment.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Hepatotoxicity: abnormal liver function tests or hepatitis in susceptible individuals.

Metformina Vir requires careful monitoring and patient education to minimise risks.

• Renal function monitoring: assess creatinine clearance before initiation and periodically thereafter.
• Hepatic disease caution: avoid use in patients with significant liver dysfunction.
• Lactic acidosis risk: discontinue promptly if patients develop unexplained acidosis, hypoxia, or severe infection.
• Pregnancy and breastfeeding: safety data are limited; use only if potential benefit justifies potential risk.
• Alcohol consumption: advise patients to limit alcohol intake as it may increase lactic acidosis risk.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Metformina Vir can interact with several medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Iodinated contrast agents: may precipitate acute renal failure and increase lactic acidosis risk.
• Cimetidine: can raise metformin plasma concentrations, enhancing toxicity.
• Alcohol: potentiates risk of lactic acidosis and hypoglycaemia.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask hypoglycaemic symptoms, requiring closer glucose monitoring.
• Diuretics (especially thiazides): can impair renal function and elevate metformin levels.