Glipizide and Metformin Hydrochloride

Glipizide and metformin hydrochloride tablets, USP are indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.

Glipizide and metformin hydrochloride tablets are contraindicated in patients with: Severe renal impairment (eGFR below 30 mlL/min/1.73 m 2 ) (see WARNINGS and PRECAUTIONS ). Known hypersensitivity to glipizide or metformin hydrochloride. Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. Diabetic ketoacidosis should be treated with insulin. WARNINGS SPECIAL WARNING ON INCREASED RISK OF CARDIOVASCULAR MORTALITY The administration of oral hypoglycemic drugs has been reported to be associated with increased cardiovascular mortality as compared to treatment with diet alone or diet plus insulin. This warning is based on the study conducted by the University Group Diabetes Program (UGDP), a long-term prospective clinical trial designed to evaluate the effectiveness of glucose-lowering drugs in preventing or delaying vascular complications in patients with non-insulin-dependent diabetes. The study involved 823 patients who were randomly assigned to 1 of 4 treatment groups ( Diabetes 19 (Suppl. 2):747-830, 1970). UGDP reported that patients treated for 5 years to 8 years with diet plus a fixed dose of tolbutamide (1.5 grams per day) had a rate of cardiovascular mortality approximately 2½ times that of patients treated with diet alone. A significant increase in total mortality was not observed, but the use of tolbutamide was discontinued based on the increase in cardiovascular mortality, thus limiting the opportunity for the study to show an increase in overall mortality. Despite controversy regarding the interpretation of these results, the findings of the UGDP study provide an adequate basis for this warning. The patient should be informed of the potential risks and benefits of glipizide and of alternative modes of therapy. Although only 1 drug in the sulfonylurea class (tolbutamide) was included in this study, it is prudent from a safety standpoint to consider that this warning may also apply to other hypoglycemic drugs in this class, in view of their close similarities in mode of action and chemical structure.

LACTIC ACIDOSIS Post-marketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias. The onset of metformin-associated lactic acidosis is often subtle, accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, somnolence, and abdominal pain. Metformin-associated lactic acidosis was characterized by elevated blood lactate levels (> 5 mmol/Liter), anion gap acidosis (without evidence of ketonuria or ketonemia), an increased lactate/pyruvate ratio; and metformin plasma levels generally > 5 mcg/mL [see PRECAUTIONS ] Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., 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, hepatic impairment, and mitochondrial disease. Steps to reduce the risk of and manage metformin-associated lactic acidosis in these high risk groups are provided [see PRECAUTIONS ]. If metformin-associated lactic acidosis is suspected, immediately discontinue glipizide and metformin hydrochloride and institute general supportive measures in a hospital setting. Prompt hemodialysis is recommended [see PRECAUTIONS ].

General: Glipizide and Metformin Hydrochloride Tablets: Lactic Acidosis —There have been post-marketing cases of metformin-associated lactic acidosis, including fatal cases. These cases had a subtle onset and were accompanied by nonspecific symptoms such as malaise, myalgias, abdominal pain, respiratory distress, or increased somnolence; however, hypotension and resistant bradyarrhythmias have occurred with severe acidosis. Metformin-associated lactic acidosis was characterized by elevated blood lactate concentrations (> 5 mmol/L), anion gap acidosis (without evidence of ketonuria or ketonemia), and an increases lactate:pyruvate ratio; metformin plasma levels were generally > 5 mcg/mL. Metformin decreases liver uptake of lactate increasing lactate blood levels which may increase the risk of lactic acidosis, especially in patients at risk. If metformin-associated lactic acidosis is suspected, general supportive measures should be instituted promptly in a hospital setting, along with immediate discontinuation of glipizide and metformin hydrochloride. In glipizide and metformin hydrochloride treated patients with a diagnosis or strong suspicion of lactic acidosis, prompt hemodialysis is recommended to correct the acidosis and remove accumulated metformin (metformin hydrochloride is dialyzable with a clearance of up to 170 mL/min under good hemodynamic conditions). Hemodialysis has often resulted in reversal of symptoms and recovery. Educate patients and their families about the symptoms of lactic acidosis and if these symptoms occur instruct them to discontinue glipizide and metformin hydrochloride and report these symptoms to their healthcare provider. For each of the known and possible risk factors for metformin-associated lactic acidosis,recommendations to reduce the risk of and manage metformin-associated lactic acidosis are provided below: o Renal Impairment —The postmarketing metformin-associated lactic acidosis cases primarily occurred in patients with significant renal impairment. The risk of metformin accumulation and metformin-associated lactic acidosis increases with the severity of renal impairment because metformin is substantially excreted by the kidney. Clinical recommendations based upon the patients renal function include (see Dosage and Administration , Clinical Pharmacology ): Before initiating glipizide and metformin hydrochloride, obtain an estimated glomerular filtration rate (eGFR) Glipizide and metformin hydrochloride is contraindicated in patients with an eGFR less than 30 mL/min/1.73 m2. Initiation of glipizide and metformin hydrochloride is not recommended in patients with eGFR between 30-45 mL/min/1.73 m2 (see Contraindications ) Obtain an eGFR at least annually in all patients taking glipizide and metformin hydrochloride. In patients at risk for the development of renal impairment (e.g., the elderly), renal function should be assessed more frequently. In patients taking glipizide and metformin hydrochloride whose eGFR falls below 45 mL/min/1.73 m2, assess the benefit and risk of continuing therapy. Drug interactions —The concomitant use of glipizide and metformin hydrochloride with specific drugs may increase the risk of metformin-associated lactic acidosis: those that impair renal function, result in significant hemodynamic change, interfere with acid-base balance, or increase metformin accumulation. Consider more frequent monitoring of patients. Age 65 or Greater —The risk of metformin-associated lactic acidosis increases with the patient's age because elderly patients have a greater likelihood of having hepatic, renal, or cardiac impairment than younger patients. Assess renal function more frequently in elderly patients. Radiologic studies with contrast —Administration of intravascular iodinated contrast agents in metformin-treated patients has led to an acute decrease in renal function and the occurrence of lactic acidosis. Stop glipizide and metformin hydrochloride at the time of, or prior to, an iodinated contrast imaging procedure in patients with an eGFR between 30 and 60 mlL/min/1.73 m 2 ; in patients with a history of hepatic impairment, alcoholism or heart failure, or in patients who will be administered intra-arterial iodinated contrast. Reevaluate eGFR 48 hours after the imaging procedure, and restart glipizide and metformin hydrochloride if renal function is stable. Surgery and other procedures —With holding of food and fluids during surgical or other procedures may increase the risk for volume depletion, hypotension, and renal impairment. Glipizide and metformin hydrochloride should be temporarily discontinued while patients have restricted food and fluid intake. Hypoxic states —Several of the postmarketing cases of metformin-associated lactic acidosis occurred in the 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 cause prerenal azotemia. When such an event occurs, discontinue glipizide and metformin hydrochloride. Excessive Alcohol intake —Alcohol is known to potentiate the effect of metformin on lactate metabolism. Patients, therefore, should be warned against excessive alcohol intake, acute or chronic, while receiving glipizide and metformin hydrochloride. Hepatic impairment —Patients with hepatic impairment have developed cases of metformin-associated lactic acidosis. This may be due to impaired lactate clearance resulting in higher lactate blood levels. Therefore, avoid use of glipizide and metformin hydrochloride in patients with clinical or laboratory evidence of hepatic disease. Mitochondrial Diseases — Metformin may increase the risk of lactic acidosis in patients with mitochondrial diseases such as mitochondrial encephalomyopathy with lactic acidosis, and stroke-like episodes (MELAS) syndrome and maternally inherited diabetes and deafness (MIDD). Glipizide and metformin hydrochloride tablets are not recommended in patients with mitochondrial diseases such as MELAS syndrome and MIDD. If a patient taking glipizide and metformin hydrochloride tablets develops elevated lactic acid levels (with or without accompanying neurologic signs and symptoms), discontinue glipizide and metformin hydrochloride tablets. Depending on the clinical context, consider evaluating the patient for MELAS, MIDD, or other mitochondrial disease. Hypoglycemia: Glipizide and metformin hydrochloride tablets are capable of producing hypoglycemia; therefore, proper patient selection, dosing, and instructions are important to avoid potential hypoglycemic episodes. The risk of hypoglycemia is increased when caloric intake is deficient, when strenuous exercise is not compensated by caloric supplementation, or during concomitant use with other glucose-lowering agents or ethanol. Renal insufficiency may cause elevated drug levels of both glipizide and metformin hydrochloride. Hepatic insufficiency may increase drug levels of glipizide and may also diminish gluconeogenic capacity, both of which increase the risk of hypoglycemic reactions. Elderly, debilitated, or malnourished patients and those with adrenal or pituitary insufficiency or alcohol intoxication are particularly susceptible to hypoglycemic effects. Hypoglycemia may be difficult to recognize in the elderly, and people who are taking beta-adrenergic blocking drugs. Glipizide: Renal and Hepatic Disease: The metabolism and excretion of glipizide may be slowed in patients with impaired renal and/or hepatic function. If hypoglycemia should occur in such patients, it may be prolonged and appropriate management should be instituted. Hemolytic Anemia: Treatment of patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency with sulfonylurea agents can lead to hemolytic anemia. […]

Glipizide and Metformin Hydrochloride Tablets: In a double-blind 24 week clinical trial involving glipizide and metformin hydrochloride tablets as initial therapy, a total of 172 patients received glipizide and metformin hydrochloride tablets, 2.5 mg/250 mg, 173 received glipizide and metformin hydrochloride tablets, 2.5 mg/500 mg, 170 received glipizide, and 177 received metformin. The most common clinical adverse events in these treatment groups are listed in Table 4 . Table 4 Clinical Adverse Events >5% in any Treatment Group, by Primary Term, in Initial Therapy Study Adverse Event Number (%) of Patients Glipizide Tablets 5 mg N=170 Metformin Tablets 500 mg N=177 Glipizide and Metformin Hydrochloride Tablets 2.5 mg/250 mg N=172 Glipizide and Metformin Hydrochloride Tablets 2.5 mg/500 mg N=173 Upper respiratory infection 12 (7.1) 15 (8.5) 17 (9.9) 14 (8.1) Diarrhea 8 (4.7) 15 (8.5) 4 (2.3) 9 (5.2) Dizziness 9 (5.3) 2 (1.1) 3 (1.7) 9 (5.2) Hypertension 17 (10) 10 (5.6) 5 (2.9) 6 (3.5) Nausea/vomiting 6 (3.5) 9 (5.1) 1 (0.6) 3 (1.7) In a double-blind 18 week clinical trial involving glipizide and metformin hydrochloride tablets as second-line therapy, a total of 87 patients received glipizide and metformin hydrochloride tablets, 84 received glipizide, and 75 received metformin. The most common clinical adverse events in this clinical trial are listed in Table 5 . Table 5 Clinical Adverse Events >5% in any Treatment Group, by Primary Term, in Second-Line Therapy Study a The dose of glipizide was fixed at 30 mg daily; doses of metformin and glipizide and metformin hydrochloride tablets were titrated. Adverse Event Number (%) of Patients Glipizide Tablets a 5 mg N=84 Metformin Tablets a 500 mg N=75 Glipizide and Metformin Hydrochloride Tablets a 5 mg/500 mg N=87 Diarrhea 11 (13.1) 13 (17.3) 16 (18.4) Headache 5 (6) 4 (5.3) 11 (12.6) Upper respiratory infection 11 (13.1) 8 (10.7) 9 (10.3) Musculoskeletal pain 6 (7.1) 5 (6.7) 7 (8) Nausea/vomiting 5 (6) 6 (8) 7 (8) Abdominal pain 7 (8.3) 5 (6.7) 5 (5.7) UTI 4 (4.8) 6 (8) 1 (1.1) Hypoglycemia: In a controlled initial therapy trial of glipizide and metformin hydrochloride tablets, 2.5 mg/250 mg and 2.5 mg/500 mg the numbers of patients with hypoglycemia documented by symptoms (such as dizziness, shakiness, sweating, and hunger) and a fingerstick blood glucose measurement ≤50 mg/dL were 5 (2.9%) for glipizide, 0 (0%) for metformin, 13 (7.6%) for glipizide and metformin hydrochloride tablets, 2.5 mg/250 mg, and 16 (9.3%) for glipizide and metformin hydrochloride tablets, 2.5 mg/500 mg. Among patients taking either glipizide and metformin hydrochloride tablets, 2.5 mg/250 mg or glipizide and metformin hydrochloride tablets, 2.5 mg/500 mg, 9 (2.6%) patients discontinued glipizide and metformin hydrochloride tablets due to hypoglycemic symptoms and 1 required medical intervention due to hypoglycemia. In a controlled second-line therapy trial of glipizide and metformin hydrochloride tablets, 5 mg/500 mg, the numbers of patients with hypoglycemia documented by symptoms and a fingerstick blood glucose measurement ≤50 mg/dL were 0 (0%) for glipizide, 1 (1.3%) for metformin, and 11 (12.6%) for glipizide and metformin hydrochloride tablets. One (1.1%) patient discontinued glipizide and metformin hydrochloride tablets therapy due to hypoglycemic symptoms and none required medical intervention due to hypoglycemia (see PRECAUTIONS ). Gastrointestinal Reactions: Among the most common clinical adverse events in the initial therapy trial were diarrhea and nausea/vomiting; the incidences of these events were lower with both glipizide and metformin hydrochloride tablets dosage strengths than with metformin therapy. There were 4 (1.2%) patients in the initial therapy trial who discontinued glipizide and metformin hydrochloride tablets therapy due to gastrointestinal (GI) adverse events. Gastrointestinal symptoms of diarrhea, nausea/vomiting, and abdominal pain were comparable among glipizide and metformin hydrochloride tablets, glipizide and metformin in the second-line therapy trial. There were 4 (4.6%) patients in the second-line therapy trial who discontinued glipizide and metformin hydrochloride tablets therapy due to GI adverse events. Glipizide Gastrointestinal Reactions Cholestatic and hepatocellular forms of liver injury accompanied by jaundice have been reported rarely in association with glipizide; glipizide and metformin hydrochloride tablets should be discontinued if this occurs.

Although it is not known whether glipizide is excreted in human milk, some sulfonylurea drugs are known to be excreted in human milk. Studies in lactating rats show that metformin is excreted into milk and reaches levels comparable to those in plasma. Similar studies have not been conducted in nursing mothers. Because the potential for hypoglycemia in nursing infants may exist, a decision should be made whether to discontinue nursing or to discontinue glipizide and metformin hydrochloride tablets, taking into account the importance of the drug to the mother. If glipizide and metformin hydrochloride tablets are discontinued, and if diet alone is inadequate for controlling blood glucose, insulin therapy should be considered.

Safety and effectiveness of glipizide and metformin hydrochloride tablets in pediatric patients have not been established.

Of the 345 patients who received glipizide and metformin hydrochloride tablets 2.5 mg/250 mg and 2.5 mg/500 mg in the initial therapy trial, 67 (19.4%) were aged 65 and older while 5 (1.4%) were aged 75 and older. Of the 87 patients who received glipizide and metformin hydrochloride tablets in the second-line therapy trial, 17 (19.5%) were aged 65 and older while 1 (1.1%) was at least aged 75. No overall differences in effectiveness or safety were observed between these patients and younger patients in either the initial therapy trial or the second-line therapy trial, and other reported clinical experience has not identified differences in response between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy and the higher risk of lactic acidosis. Assess renal function more frequently in elderly patients (see also WARNINGS , PRECAUTION and DOSAGE AND ADMINISTRATION ).

Glipizide and metformin hydrochloride tablet combines glipizide and metformin hydrochloride, 2 antihyperglycemic agents with complementary mechanisms of action, to improve glycemic control in patients with type 2 diabetes. Glipizide appears to lower blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. Extrapancreatic effects may play a part in the mechanism of action of oral sulfonylurea hypoglycemic drugs. The mechanism by which glipizide lowers blood glucose during long-term administration has not been clearly established. In man, stimulation of insulin secretion by glipizide in response to a meal is undoubtedly of major importance. Fasting insulin levels are not elevated even on long-term glipizide administration, but the postprandial insulin response continues to be enhanced after at least 6 months of treatment. Metformin hydrochloride is an antihyperglycemic agent that improves glucose tolerance in patients with type 2 diabetes, lowering both basal and postprandial plasma glucose. Metformin hydrochloride decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization.