Synjardy XR Disease Interactions

Metformin is contraindicated in patients with acute or chronic metabolic acidosis (including diabetic ketoacidosis) with or without coma. Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias; the onset is often subtle and accompanied by nonspecific symptoms (e.g., malaise, myalgias, abdominal pain, respiratory distress, increased somnolence). Risk factors include renal dysfunction, age 65 years and older, hypoxic states, excessive alcohol intake, and liver dysfunction. Lactic acidosis has been associated with metformin accumulation in plasma at levels generally exceeding 5 mcg/mL. The risk of metformin-associated lactic acidosis increases with the patient's age because patients 65 years and older have a greater likelihood of having hepatic, renal, or cardiac impairment than younger patients; renal function should be assessed more frequently in older adult patients. Several postmarketing cases of metformin-associated lactic acidosis occurred in the setting of acute congestive heart failure, especially when accompanied by hypoperfusion and hypoxemia; cardiovascular collapse (shock), acute myocardial infarction, sepsis, and other conditions associated with hypoxemia (e.g., severe anemia, asphyxia) have been associated with lactic acidosis and may cause prerenal azotemia. When such an event occurs, metformin should be discontinued. Dehydration (e.g., severe diarrhea or vomiting) may increase the risk for volume depletion, hypotension, and renal impairment; such patients may be at increased risk for lactic acidosis. Alcohol potentiates the effect of metformin on lactate metabolism; patients should be advised against excessive alcohol intake while receiving metformin. All patients treated with metformin should have renal function monitored regularly (at least annually or more frequently if necessary). If metformin-associated lactic acidosis is suspected, general supportive measures should be instituted promptly in a hospital setting, as well as immediate discontinuation of metformin. If lactic acidosis is diagnosed or strongly suspected, prompt hemodialysis is recommended to correct the acidosis and remove accumulated metformin. Patients and their families should be educated about the symptoms of lactic acidosis and, if these symptoms occur, they should be instructed to discontinue metformin and report these symptoms to their health care provider.

Metformin is not recommended in patients with clinical or laboratory evidence of liver disease. Patients with liver dysfunction have developed cases of metformin-associated lactic acidosis. Metformin decreases liver uptake of lactate increasing lactate blood levels which may increase the risk of lactic acidosis, especially in at-risk patients.

The use of metformin is contraindicated in patients with severe renal dysfunction (estimated GFR [eGFR] less than 30 mL/min/1.73 m2). Metformin is substantially excreted by the kidney; the risk of metformin accumulation and lactic acidosis increases with the degree of renal dysfunction. Before starting metformin, an eGFR should be obtained. Initiation of metformin is not recommended in patients with eGFR between 30 and 45 mL/min/1.73 m2. An eGFR should be obtained at least annually in all patients; in those at risk of developing renal dysfunction (e.g., older adult patients), renal function should be assessed more frequently. In patients whose eGFR falls below 45 mL/min/1.73 m2, the benefit/risk of continuing therapy should be assessed. Postmarketing cases of metformin-associated lactic acidosis primarily occurred with significant renal dysfunction; metformin plasma levels generally exceeded 5 mcg/mL.

The glucose lowering effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors are decreased in patients with worsening renal function. Additionally, patients with impaired renal function (estimated GFR less than 60 mL/min/1.73 m2), older adult patients, and patients on loop diuretics may be more likely to experience adverse reactions related to volume depletion such as hypotension and acute kidney injury during therapy. Renal function should be evaluated prior to treatment initiation and monitored regularly in at-risk patients. Volume status should be assessed and volume depletion corrected before initiating therapy. The use of SGLT2 inhibitors in patients undergoing dialysis is either contraindicated or not recommended. The manufacturer product information should be consulted for contraindications and indication specific renal dosing.

Hypoglycemia may commonly occur during treatment with insulin and/or oral hypoglycemic agents. Care should be taken in patients who may be particularly susceptible to the development of hypoglycemic episodes during the use of these drugs, including those who are debilitated or malnourished, those with defective counterregulatory mechanisms (e.g., autonomic neuropathy and adrenal or pituitary insufficiency), and those receiving beta-adrenergic blocking agents.

Metformin may interfere with vitamin B12 absorption from the B12-intrinsic factor complex. A decrease to subnormal levels of previously normal serum vitamin B12 levels was reported in about 7% of patients treated with metformin during clinical trials. Such decrease may be associated with anemia but appears to be rapidly reversible with metformin discontinuation or vitamin B12 supplementation. Certain patients (those with inadequate vitamin B12 or calcium intake or absorption) appear to be predisposed to developing subnormal levels of vitamin B12; caution may be warranted when metformin is administered to these patients. It is recommended to measure vitamin B12 every 2 to 3 years and hematologic parameters annually in patients on metformin. Any abnormalities should be managed.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors cause intravascular volume contraction which may lead to symptomatic hypotension after treatment initiation, especially in older adult patients, patients with impaired renal function, patients with low systolic blood pressure, or those using diuretics. Volume status should be assessed and corrected before starting treatment and patients should be monitored during therapy.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors increase the risk of genital mycotic infections. Care should be exercised when using an SGLT2 inhibitor in patients who have a history of chronic or recurrent genital mycotic infections or who are uncircumcised as these patients are more likely to develop genital mycotic infections. Patients should be monitored and treated appropriately.