Glumet XR Special Precautions

Lactic Acidosis: Lactic acidosis is rare, but serious (high mortality in the absence of prompt treatment), metabolic complication that can occur due to metformin accumulation. Reported cases of lactic acidosis in patients on metformin have occurred primarily in diabetic patients with significant renal failure. The incidence of lactic acidosis can and should be reduced by assessing also other associated risk factors eg, poorly controlled diabetes, ketosis, prolonged fasting, excessive alcohol intake, hepatic insufficiency and any condition associated with hypoxia.
Diagnosis: The risk of lactic acidosis must be considered in the event of nonspecific signs eg, muscle cramps with digestive disorders as abdominal pain and severe asthenia.
Lactic acidosis is characterised by acidotic dyspnea, abdominal pain and hypothermia followed by coma. Diagnostic laboratory findings are decreased blood pH, plasma lactate levels >5 mmol/L, and an increased anion gap and lactate/pyruvate ratio. If metabolic acidosis is suspected, metformin should be discontinued and the patient should be hospitalised immediately.
Renal Function: As metformin is excreted by the kidney, creatinine clearance and/or serum creatinine levels should be determined before initiating treatment and regularly thereafter, at least annually in patients with normal renal function or at least 2-4 times a year in patients with creatinine clearance levels at the upper limit of normal and in elderly subjects.
Decreased renal function in elderly subjects is frequent and asymptomatic. Special caution should be exercised in situations where renal function may become impaired eg, when initiating antihypertensive or diuretic therapy and when starting therapy with nonsteroidal anti-inflammatory drug (NSAID).
Administration of Iodinated Contrast Agent: As the intravascular administration of iodinated contrast materials in radiologic studies can lead to renal failure. This may lead to metformin accumulation and risk of lactic acidosis. Metformin should be discontinued prior to or at the time of the test and not reinstituted until 48 hrs, afterwards and only after renal function has been re-evaluated and found to be normal.
Surgery: Metformin hydrochloride should be discontinued 48 hrs before elective surgery under general, spinal or peridural anaesthesia. Therapy should be restarted no earlier than 48 hrs following surgery or resumption of oral nutrition and only if renal function has been established.
Others: All patients should continue the diet with regular distribution of carbohydrate intake during the day. Overweight patients should continue their energy-restricted diet.
The usual laboratory tests for diabetes monitoring should be performed regularly.
Metformin alone never causes hypoglycaemia, although caution is advised when it is used in combination with insulin or other oral antidiabetics (eg, sulphonylureas, insulin or meglitinides).
Effects on the Ability to Drive or Operate Machinery: Glumet XR monotherapy does not cause hypoglycaemia, and therefore has no effect on the ability to drive or to use machines.
However, patients should be alerted to the risk of hypoglycaemia when metformin is used in combination with other antidiabetic agents (sulphonylureas, insulin, meglitinides).
Use in pregnancy: Uncontrolled diabetes during pregnancy (gestational or permanent) is associated with increased risk of congenital abnormalities and perinatal mortality.
A limited amount of data from the use of metformin in pregnant women does not indicate an increased risk of congenital abnormalities. Animal studies do not indicate harmful effects with respect to pregnancy, embryonic or fetal development, parturition or postnatal development.
When the patient plans to become pregnant and during pregnancy, diabetes should not be treated with metformin but insulin should be used to maintain blood glucose levels as close to normal as possible in order to lower the risk of fetal malformations associated with abnormal blood glucose levels.
Use in children: In the absence of available data, Glumet XR should not be used in children.
Use in the elderly: Due to the potential for decreased renal function in elderly subjects, the metformin dosage should be adjusted based on renal function. Regular assessment of renal function is necessary.