Immediate-release: Initial dose: 500 mg orally twice a day or 850 mg orally once a day Dose titration: Increase in 500 mg weekly increments or 850 mg every 2 weeks as tolerated Maintenance dose: 2000 mg daily in divided doses Maximum dose: 2550 mg/day Extended-release: Initial dose: 500 to 1000 mg orally once a day Dose titration: Increase in 500 mg weekly increments as tolerated Maintenance dose: 2000 mg daily Maximum dose: 2500 mg daily Comments: -Metformin, if not contraindicated, is the preferred initial pharmacologic agent for treatment of type 2 diabetes mellitus. -Immediate-release: Take in divided doses 2 to 3 times a day with meals; titrate slowly to minimize gastrointestinal side effects. In general, significant responses are not observed with doses less than 1500 mg/day. -Extended-release: Take with the evening meal; if glycemic control is not achieved with 2000 mg once a day, may consider 1000 mg of extended-release product twice a day; if glycemic control is still not achieve, may switch to immediate-release product. Use: To improve glycemic control in adults with type 2 diabetes mellitus as an adjunct to diet and exercise. 10 years or older: Immediate-release: Initial dose: 500 mg orally twice a day Dose titration: Increase in 500 mg weekly increments as tolerated Maintenance dose: 2000 mg daily Maximum dose: 2000 mg daily Comments: Take in divided doses 2 to 3 times a day with meals. Titrate slowly to minimize gastrointestinal side effects. The NICE British National Formulary (BNF) and British National Formulary for Children (BNFc) sites are only available to users in the UK, Crown Dependencies and British Overseas Territories. If you believe you are seeing this page in error please contact us.
, the initial dose of metformin is 500mg or 850mg once daily in the morning with food. The maximum daily dose is 1g in two divided doses with monitoring of renal function every 3–6 months. This change to the prescribing information reflects the advice given in the NICE clinical guideline on the management of type II diabetes, namely that metformin can be used with caution in patients with renal impairment but the dose should be reviewed if the patient's e GFR drops below 45ml/min/1.73m. The metformin drug entry in MIMS has been updated to reflect the current Glucophage SPCs. The MIMS drug listings for products containing metformin in combination with other drugs (eg, dipeptidyl peptidase 4 inhibitors, SGLT2 inhibitors, pioglitazone) will be updated when the updated SPCs become available. Prescribers should refer to the product SPCs to check if a combination product is suitable for an individual patient with renal impairment. Elderly patients are more likely to have decreased renal function; contraindicated in patients with renal impairment, carefully monitor renal function in the elderly and use with caution as age increases Not for use in patients 80 years unless normal renal function established Initial and maintenance dosing of metformin should be conservative in patients with advanced age due to the potential for decreased renal function in this population Controlled clinical studies of metformin did not include sufficient numbers of elderly patients to determine whether they respond differently from younger patients Asthenia Diarrhea Flatulence Weakness Myalgia Upper respiratory tract infection Hypoglycemia GI complaints Lactic acidosis (rare) Low serum vitamin B-12 Nausea/vomiting Chest discomfort Chills Dizziness Abdominal distention Constipation Heartburn Dyspepsia 5 mmol/L), decreased blood p H, electrolyte disturbances with an increased anion gap, and an increased lactate/pyruvate ratio; when metformin is implicated as the cause of lactic acidosis, metformin plasma concentrations 5 mcg/m L are generally found Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (eg, carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, and hepatic impairment; if metformin-associated lactic acidosis is suspected, immediately discontinue Patients with CHF requiring pharmacologic management, in particular those with unstable or acute CHF who are at risk for hypoperfusion and hypoxemia, are at an increased risk for lactic acidosis; the risk for lactic acidosis increases with the degree of renal dysfunction and the patient’s age Do not start in patients aged 80 years or older unless Cr Cl demonstrates that renal function is not reduced, because these patients are more susceptible to developing lactic acidosis; metformin should be promptly withheld in the presence of any condition associated with hypoxemia, dehydration, or sepsis Should generally be avoided in patients with clinical or laboratory evidence of hepatic disease; patients should be cautioned against excessive alcohol intake, either acute or chronic, during metformin therapy because alcohol potentiates the effects of metformin on lactate metabolism Discontinue metformin at the time of or before an iodinated contrast imaging procedure in patients with an e GFR between 30-60 m L/minute/1.73 m²; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinate contrast The onset of lactic acidosis often is subtle and accompanied by nonspecific symptoms (eg, malaise, myalgias, respiratory distress, increasing somnolence, nonspecific abdominal distress); with marked acidosis, hypothermia, hypotension, and resistant bradyarrhythmias may occur; patients should be instructed regarding recognition of these symptoms and told to notify their physician immediately if the symptoms occur; metformin should be withdrawn until the situation is clarified; serum electrolytes, ketones, blood glucose, and, if indicated, blood p H, lactate levels, and even blood metformin levels may be useful Once a patient is stabilized on any dose level of metformin, GI symptoms, which are common during initiation of therapy, are unlikely to be drug related; later occurrences of GI symptoms could be due to lactic acidosis or other serious disease Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis who is lacking evidence of ketoacidosis (ketonuria and ketonemia); lactic acidosis is a medical emergency that must be treated in a hospital setting; in a patient with lactic acidosis who is taking metformin, the drug should be discontinued immediately and general supportive care measures promptly instituted; metformin is highly dialyzable (clearance up to 170 m L/min under good hemodynamic conditions); prompt hemodialysis is recommended to correct the acidosis and to remove the accumulated metformin; such management often results in prompt reversal of symptoms and recovery Increased risk of severe hypoglycemia especially in elderly, debilitated or malnourished, adrenal or pituitary insufficiency, dehydration, heavy alcohol use, hypoxic states, hepatic/renal impairment, stress due to infection, fever, trauma, or surgery Concomitant administration of insulin and insulin secretagogues (e.g., sulfonylurea) may increase risk of hypoglycemia; therefore, a lower dose of insulin or insulin secretagogue may be required to minimize risk of hypoglycemia when used in combination with metformin Withholding of food and fluids during surgical or other procedures may increase risk for volume depletion, hypotension, and renal impairment; therapy should be temporarily discontinued while patients have restricted food and fluid intake Rare lactic acidosis may occur due to metformin accumulation; fatal in approximately 50% of cases; risk increases with age, degree of renal dysfunction, and with unstable or acute CHF; if metformin-associated lactic acidosis suspected, general supportive measures should be instituted promptly in a hospital setting, along with immediate discontinuation of therapy; in patients with a diagnosis or strong suspicion of lactic acidosis, prompt hemodialysis is recommended to correct acidosis and remove accumulated metformin (metformin hydrochloride is dialyzable, with a clearance of up to170 m L/minute under good hemodynamic conditions); hemodialysis has often resulted in reversal of symptoms and recovery Possible increased risk of CV mortality May cause ovulation in anovulatory and premenopausal PCOS patients May be necessary to discontinue therapy with metformin and administer insulin if patient is exposed to stress (fever, trauma, infection), or experiences diabetic ketoacidosis Several of the postmarketing cases of metformin-associated lactic acidosis occurred in setting of acute congestive heart failure (particularly when accompanied by hypoperfusion and hypoxemia); cardiovascular collapse (shock) acute myocardial infarction, sepsis, and other conditions associated with hypoxemia have been associated with lactic acidosis and may also cause prerenal azotemia; discontinue therapy when such events occur May impair vitamin B12 or calcium intake/absorption; monitor B12 serum concentrations periodically with long-term therapy Not indicated for use in patients with type 1 diabetes mellitus that are insulin dependent due to lack of efficacy Withhold in patients with dehydration and/or prerenal azotemia Conclusive evidence of macrovascular risk reduction with metformin not established Limited data with in pregnant women are not sufficient to determine drug-associated risk for major birth defects or miscarriage; published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk; poorly-controlled diabetes mellitus in pregnancy increases maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, stillbirth and delivery complications; poorly controlled diabetes mellitus increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity Limited published studies report that metformin is present in human milk; however, there is insufficient information to determine effects of metformin on breastfed infant and no available information on effects of metformin on milk production; therefore, developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed child from therapy or from the underlying maternal condition The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.
Jan 22, 2018. dating the optimal metformin dose as a function of the CKD stage 3A, 3B, and. Provided that the dose is adjusted for renal function, metformin. Metformin may be used in patients with reduced but stable renal. for the initiation and adjustment of therapy A consensus statement from.