Benformin

Metformin is a biguanide type oral antihyperglycemic drug used in the management of type 2 diabetes. It lowers both basal and postprandial plasma glucose. Its mechanism of action is different from those of sulfonylureas and it does not produce hypoglycemia. Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose and improves insulin sensitivity by an increase in peripheral glucose uptake and utilization.

Co-administration with Carbonic anhydrase (Topiramate, Zonisamide) may increase risk of lactic acidosis. Drugs (Ranolazine, Dolutegravir, Cimetidine) that reduce Metformin clearance may increase the accumulation of Metformin. Alcohol can potentiate the effect of Metformin on lactate metabolism.

Blood and lymphatic system disorders: Not known: Hemolytic anemia

Metabolism and nutrition disorders: Very rare: Lactic acidosis. Decrease of vitamin B12 absorption with a decrease of serum levels during long-term use of metformin. Consideration of such etiology is recommended if a patient presents with megaloblastic anemia. Cases of peripheral neuropathy in patients with vitamin B12 deficiency have been reported in post-marketing experience (frequency not known)

Nervous system disorders: Common: Taste disturbance. Not known: Encephalopathy

Gastrointestinal disorders: Very common: Gastrointestinal disorders, such as nausea, vomiting, diarrhea, abdominal pain, and loss of appetite. These undesirable effects occur most frequently during the initiation of therapy and resolve spontaneously in most cases. To prevent them, it is recommended that metformin be taken in 2 or 3 daily doses during or after meals. A slow increase of the dose may also improve gastrointestinal tolerability.

Hepatobiliary disorders: Very rare: Isolated reports of liver function test abnormalities or hepatitis resolving upon metformin discontinuation.

Skin and subcutaneous tissue disorders: Very rare: Skin reactions, such as erythema, pruritus, urticaria.

Pregnancy: Uncontrolled diabetes during pregnancy (gestational or permanent) is associated with an increased risk of congenital abnormalities and perinatal mortality. When the patient plans to become pregnant and during pregnancy, it is recommended that diabetes is not treated with metformin but insulin be used to maintain blood glucose levels as close to normal as possible, to reduce the risk of malformations of the foetus.

Breastfeeding: Metformin is excreted into human breast milk. No adverse efects were observed in breastfed newborns/infants. However, as only limited data are available, breastfeeding is not recommended during metformin treatment. A decision on whether to discontinue breastfeeding should be made, taking into account the benefit of breastfeeding and the potential risk to adverse effects on the child.

Metformin Hydrochloride is known to be substantially excreted by the kidney and the risk of Metformin accumulation and lactic acidosis increases with the degree of impairment of renal function. Metformin may lower vitamin B12 level. It also increases risk of hypoglycemia when use in combination with insulin or insulin secretagogue.

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.

Pediatric population: The diagnosis of type 2 diabetes mellitus should be confirmed before treatment with metformin is initiated. No effect of metformin on growth and puberty has been detected during controlled clinical studies of one-year duration but no long-term data on these specific points are available. Therefore, a careful follow-up of the effect of metformin on these parameters in metformin-treated children, especially prepubescent children, is recommended.

Children aged between 10 and 12 years: Particular caution is recommended when prescribing to children aged between 10 and 12 years.

Renal function: As metformin is excreted by the kidney, creatinine clearance (this can be estimated from serum creatinine levels by using the Cockcroft-Gault formula) should be determined before initiating treatment and regularly thereafter:

• At least annually in patients with normal renal function,
• At least two to four times a year in patients with creatinine clearance at the lower 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, for example when initiating antihypertensive therapy or diuretic therapy and when starting therapy with a non-steroidal anti-inflammatory drug (NSAID). GFR should be assessed before treatment initiation and regularly thereafter. Metformin is contraindicate in patients with GFR<30 ml/min and should be temporarily discontinued in the presence of conditions that alter renal function.

Biguanides

Hypoglycemia has not been seen with Metformin doses up to 85 gm, although lactic acidosis has occurred in such circumstances. Lactic acidosis is a medical emergency and must be treated in hospital. The most effective method to remove lactate and Metformin is hemodialysis.

Keep below 30°C temperature, protected from light & moisture. Keep out of the reach of children.