Glucoxit Overdosage

Overdosage of metformin produces hypoglycemia and lactic acidosis.
Hemodialysis with sodium bicarbonate has been used but is controversial because there is a lack of published information concerning outcome and lack of cases of metformin-induced lactic acidosis; peritoneal dialysis also has been used, but hemodialysis is thought to be the preferred method when dialysis is needed, such as in patients with shock syndrome. Dialysis is probably not necessary when renal function could be restored because of metformin's rapid renal elimination. Dialysis solutions commonly contain lactate as the buffering agent and these should not be used in cases of metformin-induced lactic acidosis.
Mild to moderate hypoglycaemia is treated with immediate digestion of a source of sugar, such as glucose gel, glucose tablets, fruit juice, non-diet soft drinks, honey, sugar cubes, or table sugar dissolved in water. A frequently used source of sugar is a glassful of orange juice. Blood glucose should be checked every 15 minutes. Patient should be advised to seek medical assistance promptly. There may be a need to adjust dosage of metforrnin or meal pattern.
Severe hypoglycaemia or acute overdose, including coma, requires emergency medical assistance immediately. Dextrose 50% is given intravenously to stabilise the patient. Then, administer a continuous infusion of 5%-10% dextrose in water to maintain slight hyperglycaemia for up to 12 days. Glucagon, 1-2 mg administered intramuscularly, is useful for fast onset of action to mobilise hepatic glucose stores but may be ineffective or variable in its effect if glycogen stores are depleted and must follow the use of glucose. Diazoxide therapy can be used for nonresponders to glucose therapy or for patients in a coma as an aid to glucose infusion to reduce hypoglycaemia; patient should be monitored for sodium concentration and for hypotension. Emesis can be induced with syrup of ipecac if overdose is recent (within the past 30 minutes) if patient is alert, has an intact gag reflex, and is not obtunded or convulsing. Otherwise, gastric lavage after endotracheal tube placement is required. Vital signs, arterial blood gases, blood glucose, and serum electrolytes (especially calcium, potassium, and sodium) should be monitored as required. Initially, blood glucose concentrations should be monitored as frequently as every 1-3 hours. Blood urea nitrogen and serum creatinine concentrations should also be obtained. Cerebral edema can be managed with mannitol and dexamethasone while patients with hypokalaemia should be given potassium supplements. Patient should be hospitalised for 6-91 hours (mean, 24 hours) because the hypoglycaemia may be recurrent and prolonged. Other supportive measures should also be employed as needed.
Up-to-date information on treatment of overdose can be obtained from The National Poison Centre, Universiti Sains Malaysia.