Glucoxit Special Precautions

Metformin hydrochloride should be used with care in conditions that decrease or delay stomach emptying such as diarrhoea, gastroparesis, intestinal obstruction, vomiting or other conditions cause delayed food absorption. Female hormonal changes, high fever, hypercortisolism and psychological stress may predispose to hyperglycaemia while adrenal insufficiency, debilitated physical condition, malnutrition and pituitary insufficiency inherently predispose patients to the risk of developing hypoglycaemia. These conditions warrant a need for more frequent glucose monitoring and for a temporary or permanent adjustment of metformin dosages. Hyperthyroidism aggravates diabetes mellitus by increasing plasma glucose concentrations and glucose absorption and impairing glucose tolerance while hypothyroidism is associated with reduced glucose absorption and altered glucose and lipoprotein metabolism. Glycaemic control may be difficult until the patient is euthyroid.
Serum folic acid and Vitamin B12 concentration determinations are recommended every 1-2 years during long-term metformin therapy because metformin may interfere with their absorption serum glucose concentration should be routinely self-monitored by the patients at home (several times a day or once to several times a week) and by the physicians (every 3 months or more often when patient is not stabilized). Monitoring of urine for the presence of glucose and ketones may be necessary if blood glucose levels exceed 200 mg/dL. Glycosylated hemoglobin (hemoglobin A) reflects the blood glucose control over the preceding 3 months. Monitoring of this parameter should be done every 3 months or as often as necessary; however this does not eliminate the need for daily blood glucose monitoring. Hemoglobin A is falsely elevated in unstable diabetics when the intermediate precursor is elevated (in alcoholism) and falsely lowered in conditions of shortened red blood cell lifespan (in anemia and acute or chronic blood loss) or in patients with hemoglobinopathies (sickle cell). Regular physical examinations are recommended as often as necessary to reassess appropriateness of continuation of metformin therapy. Renal function assessment is recommended annually, and more often for high risk patients.
Metformin hydrochloride may produce false positive diagnostic test results for ketones in urine. The effects of metformin on total serum cholesterol, serum low density lipoproteins and serum triglycerides in NIDDM patients are inconsistent and may depend on weight control. Generally, concentrations of these lipid subfractions may be lowered or unchanged in metformin users. This is thought to be independent of metformin's glucose lowering effect; it may involve suppression of free fatty acid oxidation and lipid oxidation or reduction in the triglyceride content of the LDL and VLDL fractions by metformin.
Serum high density lipoprotein (HDL) may be slightly increased or unchanged. Fasting serum lactate may increase to the upper range of normal, or to show no change with therapeutic doses; although the source is unknown, any small increase is thought to be due to glucose metabolism in the splanchnic beds, not in skeletal muscle.
Lactic acidosis: Lactic acidosis, a very rare but serious metabolic complication, most often occurs at acute worsening of renal function or cardiorespiratory illness or sepsis. Metformin accumulation occurs at acute worsening of renal function and increases the risk of lactic acidosis. In case of dehydration (severe diarrhoea or vomiting, fever or reduced fluid intake), metformin should be temporarily discontinued and contact with a health care professional is recommended. Medicinal products that can acutely impair renal function (such as antihypertensives, diuretics and NSAIDs) should be initiated with caution in metformin-treated patients. Other risk factors for lactic acidosis are excessive alcohol intake, hepatic insufficiency, inadequately controlled diabetes, ketosis, prolonged fasting and any conditions associated with hypoxia, as well as concomitant use of medicinal products that may cause lactic acidosis. Patients and/or care-givers should be informed of the risk of lactic acidosis. Lactic acidosis is characterised by acidotic dyspnoea, abdominal pain, muscle cramps, asthenia and hypothermia followed by coma. In case of suspected symptoms, the patient should stop taking metformin and seek immediate medical attention. Diagnostic laboratory findings are decreased blood pH (< 7.35), increased plasma lactate levels (>5 mmol/L) and an increased anion gap and lactate/pyruvate ratio.
Renal function: GFR should be assessed before treatment initiation and regularly there after [See Dosage & Administration]. Metformin is contraindicated in patients with GFR <30 mL/min and should be temporarily discontinued in the presence of conditions that alter renal function [See Contraindications].