Metfor XR

500 mg: Risk reduction or delayed onset of type 2 DM in adult, overwt patients w/ impaired glucose tolerance &/or impaired fasting glucose, &/or increased HbA1C who are w/ high risk for developing overt type 2 DM & still improving towards type 2 DM despite exertion of intensive change in lifestyle for 3-6 mth. Monotherapy or in combination w/ other oral diabetes medications or insulin for treatment of type 2 DM in adults, particularly in obese patients, when food & exercise therapy alone do not achieve optimal glycemic control. 750 mg: Management of type 2 DM as monotherapy, & as adjunct to diet & exercise to improve glycemic control.

500 mg Adult w/ normal renal function (GFR ≥90 mL/min) Risk reduction or delayed onset of type 2 diabetes Initially 500 mg once daily, adjust dose after 10-15 days based on blood glucose measurements. Max: 2,000 mg once daily. Type 2 DM Monotherapy: Initially 500 mg once daily, adjust dose after 10-15 days based on blood glucose measurements; increase dose in 500 mg increments every 10-15 days up to max dose 2,000 mg once daily. If glycemic control is not achieved on 2,000 mg once daily, consider 1,000 mg bid. If glycemic control is still not reached, patient may be changed to standard metformin tab w/ max dose 3,000 mg daily. Combination w/ insulin: Initially 500 mg once daily, while insulin dose is adjusted based on blood glucose measurements. Patient w/ GFR 60-89 mL/min Max: 2,000 mg daily, 45-59 mL/min Starting dose is at most ½ max dose. Max: 2,000 mg daily, 30-44 mL/min Starting dose is at most ½ max dose. Max: 1,000 mg daily. 750 mg Adult Monotherapy & combination w/ other oral hypoglycemic agents: Initially 750 mg. Max: 1,500 mg. Patient treated w/ combination therapy of metformin & insulin Metformin 750 mg up to max 1,500 mg; adjust insulin dose based on blood glucose measurements.

Should be taken with food: Take w/ the evening meal. Swallow whole, do not chew/crush.

Hypersensitivity. Any type of acute metabolic acidosis (eg, lactic acidosis, diabetic ketoacidosis). Diabetic pre-coma. Acute conditions w/ potential to alter renal function eg, dehydration, severe infection, or shock. Disease (especially acute disease or worsening of chronic disease) which may cause tissue hypoxia eg, unstable CHF, resp failure, recent MI or shock. Severe renal failure (CrCl <30 mL/min or eGFR <30 mL/min/1.73 m²). Hepatic insufficiency, acute alcohol intoxication, alcoholism.

Discontinue use 48 hr prior to elective major surgical interventions & do not reinstitute until 48 hr afterwards, & only after renal function has been re-evaluated & has not deteriorated further. Risk of lactic acidosis. Immediately & temporarily discontinue treatment in situations where renal function may become acutely impaired [eg, dehydration (severe or prolonged diarrhea or vomiting)] or when initiating drugs which can acutely impair renal function (eg, antihypertensives, diuretics & NSAIDs). Determine CrCl or eGFR prior to initiating treatment & regularly thereafter. May be used in patients w/ stable chronic heart failure w/ regular monitoring of cardiac & renal function. Risk of hypoglycemia in combination w/ insulin, sulphonylureas or meglitinides. Maintain energy-restricted diet (overwt patient). Regularly perform usual/standard lab tests for diabetes monitoring. Tab shells may be present in feces. Not recommended during pregnancy & breast-feeding. 500 mg: Not recommended in patients w/ acute or unstable heart failure. Stop treatment prior to or during imaging process & do not resume for at least 48 hr, assuming renal function has been re-evaluated & determined to be stable. Stop before undergoing surgery under general, spinal, or epidural anesth; continue therapy no sooner than 48 hr after surgery or commencement of oral nourishment, & only after renal function has been re-evaluated & proven to be stable. Examine vit B₁₂ serum levels if there is suspicion of vit B₁₂ deficiency (eg, anemia or neuropathy). Caution in concomitant use w/ antihypertensives, diuretics, & NSAIDs. Not to be used in childn. Not advisable in elderly ≥75 yr.

Diarrhea; taste disturbance/disorder. 500 mg: GI disorders (eg, nausea, vomiting, abdominal pain & loss of appetite). Decrease or deficiency in vit B₁₂ levels. 750 mg: Abnormal stools, hypoglycemia, myalgia, light-headedness, dyspnea, nail disorder, rash, increased sweating, chest discomfort, chills, flu syndrome, flushing, & palpitations.

More frequent blood glucose monitoring may be required, especially at beginning of treatment, in concomitant use w/ medicinal products w/ intrinsic hyperglycemic activity eg, glucocorticoids & tetracosactides (systemic & local routes), β₂-agonists, danazol, & chlorpromazine at high doses (100 mg daily), diuretics, sympathomimetics. Efficacy may be reduced w/ OCT1 substrates/inhibitors (eg, verapamil). GI absorption & efficacy may be enhanced/increased w/ OCT1 inducers (eg, rifampicin). Renal elimination may be reduced/decreased & thus lead to enhanced/increased plasma conc w/ OCT2 substrates/inhibitors (eg, cimetidine, dolutegravir, crizotinib, olaparib, daclatasvir, ranolazine, trimethoprim, vandetanib, isavuconazole). 500 mg: May result in contrast-induced nephropathy which can lead to metformin build-up & increased risk of lactic acidosis w/ IV inj iodinated contrast agents. Increased risk of lactic acidosis w/ alcohol, especially when combined w/ fasting, malnutrition, or hepatic impairment. Impaired renal function & raised risk of lactic acidosis w/ NSAIDs eg, selective COX II inhibitors, ACE inhibitors, angiotensin II receptor antagonists, & diuretics, particularly loop diuretics. Efficacy & renal elimination may be changed w/ both OCT1 & OCT2 inhibitors (eg, crizotinib, olaparib). 750 mg: Enhanced absorption w/ nifedipine. Potential interaction w/ cationic drugs (eg, amiloride, digoxin, morphine, procainamide, quinidine, quinine, ranitidine, triamterene, trimethoprim, or vancomycin) due to competition for common renal tubular transport systems. Increased peak plasma & whole blood conc w/ cimetidine. Potential hyperglycemia & may lead to loss of glycemic control w/ thiazides & other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, OCs, phenytoin, nicotinic acid, sympathomimetics, Ca channel blockers, & INH.

Antidiabetic Agents

A10BA02 - metformin ; Belongs to the class of biguanides. Used in the treatment of diabetes.

Rx