Tablets USP · New Horizon Rx Group, LLC
Dosage Form
Tablets USP
Manufacturer
New Horizon Rx Group, LLC
This medication contains important usage instructions, warnings, and side effect information that you should review before use.
Metformin Hydrochloride Tablets USP, is indicated as an adjunct to diet and exercise to improve glycemic control in adults and children with type 2 diabetes mellitus.
There is no fixed dosage regimen for the management of hyperglycemia in patients with type 2 diabetes with metformin hydrochloride or any other pharmacologic agent. Dosage of metformin hydrochloride must be individualized on the basis of both effectiveness and tolerance, while not exceeding the maximum recommended daily doses. The maximum recommended daily dose of metformin hydrochloride is 2550 mg in adults and 2000 mg in pediatric patients (10 to 16 years of age).
Metformin hydrochloride should be given in divided doses with meals. Metformin hydrochloride should be started at a low dose, with gradual dose escalation, both to reduce gastrointestinal side effects and to permit identification of the minimum dose required for adequate glycemic control of the patient.
During treatment initiation and dose titration (see Recommended Dosing Schedule), fasting plasma glucose should be used to determine the therapeutic response to metformin hydrochloride and identify the minimum effective dose for the patient. Thereafter, glycosylated hemoglobin should be measured at intervals of approximately three months. The therapeutic goal should be to decrease both fasting plasma glucose and glycosylated hemoglobin levels to normal or near normal by using the lowest effective dose of metformin hydrochloride, either when used as monotherapy or in combination with sulfonylurea or insulin.
Monitoring of blood glucose and glycosylated hemoglobin will also permit detection of primary failure, i.e., inadequate lowering of blood glucose at the maximum recommended dose of medication, and secondary failure, i.e., loss of an adequate blood glucose lowering response after an initial period of effectiveness.
Short-term administration of metformin hydrochloride may be sufficient during periods of transient loss of control in patients usually well-controlled on diet alone.
Metformin Hydrochloride Tablets USP is contraindicated in patients with:
Metformin Hydrochloride Tablets USP should be temporarily discontinued in patients undergoing radiologic studies involving intravascular administration of iodinated contrast materials, because use of such products may result in acute alteration of renal function. (See also PRECAUTIONS.)
Glyburide—In a single-dose interaction study in type 2 diabetes patients, coadministration of metformin and glyburide did not result in any changes in either metformin pharmacokinetics or pharmacodynamics. Decreases in glyburide AUC and Cmax were observed, but were highly variable. The single-dose nature of this study and the lack of correlation between glyburide blood levels and pharmacodynamic effects, makes the clinical significance of this interaction uncertain (see DOSAGE AND ADMINISTRATION: Concomitant Metformin Hydrochloride Tablets USP and Oral Sulfonylurea Therapy in Adult Patients).
Furosemide—A single-dose, metformin-furosemide drug interaction study in healthy subjects demonstrated that pharmacokinetic parameters of both compounds were affected by coadministration. Furosemide increased the metformin plasma and blood Cmax by 22% and blood AUC by 15%, without any significant change in metformin renal clearance. When administered with metformin, the Cmax and AUC of furosemide were 31% and 12% smaller, respectively, than when administered alone, and the terminal half-life was decreased by 32%, without any significant change in furosemide renal clearance. No information is available about the interaction of metformin and furosemide when coadministered chronically.
Nifedipine—A single-dose, metformin-nifedipine drug interaction study in normal healthy volunteers demonstrated that coadministration of nifedipine increased plasma metformin Cmax and AUC by 20% and 9%, respectively, and increased the amount excreted in the urine. Tmax and half-life were unaffected. Nifedipine appears to enhance the absorption of metformin. Metformin had minimal effects on nifedipine.
Cationic drugs—Cationic drugs (e.g., amiloride, digoxin, morphine, procainamide, quinidine, quinine, ranitidine, triamterene, trimethoprim, or vancomycin) that are eliminated by renal tubular secretion theoretically have the potential for interaction with metformin by competing for common renal tubular transport systems. Such interaction between metformin and oral cimetidine has been observed in normal healthy volunteers in both single- and multiple-dose, metformin-cimetidine drug interaction studies, with a 60% increase in peak metformin plasma and whole blood concentrations and a 40% increase in plasma and whole blood metformin AUC. There was no change in elimination half-life in the single-dose study. Metformin had no effect on cimetidine pharmacokinetics. Although such interactions remain theoretical (except for cimetidine), careful patient monitoring and dose adjustment of Metformin Hydrochloride Tablets USP and/or the interfering drug is recommended in patients who are taking cationic medications that are excreted via the proximal renal tubular secretory system.
Other—Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control. These drugs include the thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blocking drugs, and isoniazid. When such drugs are administered to a patient receiving Metformin Hydrochloride Tablets USP, the patient should be closely observed for loss of blood glucose control. When such drugs are withdrawn from a patient receiving Metformin Hydrochloride Tablets USP, the patient should be observed closely for hypoglycemia.
In healthy volunteers, the pharmacokinetics of metformin and propranolol, and metformin and ibuprofen were not affected when coadministered in single-dose interaction studies.
Metformin is negligibly bound to plasma proteins and is, therefore, less likely to interact with highly protein-bound drugs such as salicylates, sulfonamides, chloramphenicol, and probenecid, as compared to the sulfonylureas, which are extensively bound to serum proteins.
In a US double-blind clinical study of Metformin Hydrochloride Tablets USP in patients with type 2 diabetes, a total of 141 patients received Metformin Hydrochloride Tablets USP therapy (up to 2550 mg per day) and 145 patients received placebo. Adverse reactions reported in greater than 5% of the Metformin Hydrochloride Tablets USP patients, and that were more common in Metformin Hydrochloride Tablets USP- than placebo-treated patients, are listed in Table 9.
| * Reactions that were more common in Metformin Hydrochloride Tablets USP- than placebo-treated patients. | ||
| Table 9: | Most Common Adverse Reactions (>5.0 Percent) in a Placebo-Controlled Clinical Study of Metformin Hydrochloride Tablets Monotherapy* | |
| Adverse Reaction | Metformin Hydrochloride Tablets Monotherapy (n=141) | Placebo (n=145) |
| % of Patients | ||
| Diarrhea | 53.2 | 11.7 |
| Nausea/Vomiting | 25.5 | 8.3 |
| Flatulence | 12.1 | 5.5 |
| Asthenia | 9.2 | 5.5 |
| Indigestion | 7.1 | 4.1 |
| Abdominal Discomfort | 6.4 | 4.8 |
| Headache | 5.7 | 4.8 |
Diarrhea led to discontinuation of study medication in 6% of patients treated with Metformin Hydrochloride Tablets USP. Additionally, the following adverse reactions were reported in ≥1.0 to ≤5.0% of Metformin Hydrochloride Tablets USP patients and were more commonly reported with Metformin Hydrochloride Tablets USP than placebo: abnormal stools, hypoglycemia, myalgia, lightheaded, dyspnea, nail disorder, rash, sweating increased, taste disorder, chest discomfort, chills, flu syndrome, flushing, palpitation.
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 the drug, taking into account the importance of the drug to the mother. If Metformin Hydrochloride Tablets USP is discontinued, and if diet alone is inadequate for controlling blood glucose, insulin therapy should be considered.
The safety and effectiveness of Metformin Hydrochloride Tablets USP for the treatment of type 2 diabetes have been established in pediatric patients ages 10 to 16 years (studies have not been conducted in pediatric patients below the age of 10 years). Use of Metformin Hydrochloride Tablets USP in this age group is supported by evidence from adequate and well-controlled studies of Metformin Hydrochloride Tablets USP in adults with additional data from a controlled clinical study in pediatric patients ages 10 to 16 years with type 2 diabetes, which demonstrated a similar response in glycemic control to that seen in adults. (See CLINICAL PHARMACOLOGY: Pediatric Clinical Studies.) In this study, adverse effects were similar to those described in adults. (See ADVERSE REACTIONS: Pediatric Patients.) A maximum daily dose of 2000 mg is recommended. (See DOSAGE AND ADMINISTRATION: Recommended Dosing Schedule: Pediatrics.)
Controlled clinical studies of Metformin Hydrochloride Tablets USP did not include sufficient numbers of elderly patients to determine whether they respond differently from younger patients, although other reported clinical experience has not identified differences in responses between the elderly and younger patients. Metformin is known to be substantially excreted by the kidney and because the risk of serious adverse reactions to the drug is greater in patients with impaired renal function, Metformin Hydrochloride Tablets USP should only be used in patients with normal renal function (see CONTRAINDICATIONS, WARNINGS, and CLINICAL PHARMACOLOGY: Pharmacokinetics). Because aging is associated with reduced renal function, Metformin Hydrochloride Tablets USP should be used with caution as age increases. Care should be taken in dose selection and should be based on careful and regular monitoring of renal function. Generally, elderly patients should not be titrated to the maximum dose of Metformin Hydrochloride Tablets USP (see also WARNINGS and DOSAGE AND ADMINISTRATION).
Overdose of metformin hydrochloride has occurred, including ingestion of amounts greater than 50 grams. Hypoglycemia was reported in approximately 10% of cases, but no causal association with metformin hydrochloride has been established. Lactic acidosis has been reported in approximately 32% of metformin overdose cases (see WARNINGS). Metformin is dialyzable with a clearance of up to 170 mL/min under good hemodynamic conditions. Therefore, hemodialysis may be useful for removal of accumulated drug from patients in whom metformin overdosage is suspected.
Patients should be informed of the potential risks and benefits of Metformin Hydrochloride Tablets USP and of alternative modes of therapy. They should also be informed about the importance of adherence to dietary instructions, of a regular exercise program, and of regular testing of blood glucose, glycosylated hemoglobin, renal function, and hematologic parameters.
The risks of lactic acidosis, its symptoms, and conditions that predispose to its development, as noted in the WARNINGS and PRECAUTIONS sections, should be explained to patients. Patients should be advised to discontinue Metformin Hydrochloride Tablets USP immediately and to promptly notify their health practitioner if unexplained hyperventilation, myalgia, malaise, unusual somnolence, or other nonspecific symptoms occur. Once a patient is stabilized on any dose level of Metformin Hydrochloride Tablets USP, gastrointestinal symptoms, which are common during initiation of metformin therapy, are unlikely to be drug related. Later occurrence of gastrointestinal symptoms could be due to lactic acidosis or other serious disease.
Patients should be counselled against excessive alcohol intake, either acute or chronic, while receiving Metformin Hydrochloride Tablets USP.
Metformin Hydrochloride Tablets USP alone does not usually cause hypoglycemia, although it may occur when Metformin Hydrochloride Tablets USP is used in conjunction with oral sulfonylureas and insulin. When initiating combination therapy, the risks of hypoglycemia, its symptoms and treatment, and conditions that predispose to its development should be explained to patients and responsible family members. (See Patient Information printed below.)
Metformin Hydrochloride Tablets USP are oral antihyperglycemic drugs used in the management of type 2 diabetes. Metformin hydrochloride (N,N-dimethylimidodicarbonimidic diamide hydrochloride) is not chemically or pharmacologically related to any other classes of oral antihyperglycemic agents. The structural formula is as shown:
[image: MM1]Metformin hydrochloride is a white to off-white crystalline compound with a molecular formula of C4H11N5 • HCl and a molecular weight of 165.63. Metformin hydrochloride is freely soluble in water and is practically insoluble in acetone, ether, and chloroform. The pKa of metformin is 12.4. The pH of a 1% aqueous solution of metformin hydrochloride is 6.68.
Metformin Hydrochloride Tablets USP contain 500 mg of metformin hydrochloride. Each tablet contains the inactive ingredients povidone (K-30), povidone (K-90), pregelatinized starch, and magnesium stearate. In addition, the coating for the tablets contains hypromellose and polyethylene glycol.
Metformin Hydrochloride Tablets, USP
500 mg - White to off-white, round, biconvex, film coated tablets debossing “H/102” on one side and plain on the other side.
Bottles of 90 NDC 58517-040-90
Storage
Store at 20°–25° C (68°–77° F); excursions permitted to 15°–30° C (59°–86° F). [See USP Controlled Room Temperature.]
Dispense in tight, light-resistant containers with child-resistant closure.
Distributed by:
New Horizon Rx Group, LLC
Kenner, LA 70062
Manufactured by:
Granules India Limited
Ranga Reddy Dist., India 500-043 AP
Rev. 11/13
Patient Information
Metformin Hydrochloride Tablets USP
Read this information carefully before you start taking this medicine and each time you refill your prescription. There may be new information. This information does not take the place of your doctor’s advice. Ask your doctor or pharmacist if you do not understand some of this information or if you want to know more about this medicine.
What are Metformin Hydrochloride Tablets USP?
Metformin Hydrochloride Tablets USP are used to treat type 2 diabetes. This is also known as non-insulin-dependent diabetes mellitus. People with type 2 diabetes are not able to make enough insulin or respond normally to the insulin their bodies make. When this happens, sugar (glucose) builds up in the blood. This can lead to serious medical problems including kidney damage, amputations, and blindness. Diabetes is also closely linked to heart disease. The main goal of treating diabetes is to lower your blood sugar to a normal level.
High blood sugar can be lowered by diet and exercise, by a number of medicines taken by mouth, and by insulin shots. Before you take Metformin Hydrochloride Tablets USP, try to control your diabetes by exercise and weight loss. While you take your diabetes medicine, continue to exercise and follow the diet advised for your diabetes. No matter what your recommended diabetes management plan is, studies have shown that maintaining good blood sugar control can prevent or delay complications of diabetes, such as blindness.
Metformin Hydrochloride Tablets USP can help control your blood sugar in a number of ways. These include helping your body respond better to the insulin it makes naturally, decreasing the amount of sugar your liver makes, and decreasing the amount of sugar your intestines absorb. Metformin Hydrochloride Tablets USP do not cause your body to make more insulin. Because of this, when taken alone, it rarely cause hypoglycemia (low blood sugar), and usually do not cause weight gain. However, when it is taken with a sulfonylurea or with insulin, hypoglycemia is more likely to occur, as is weight gain.
WARNING: A small number of people who have taken Metformin Hydrochloride Tablets USP have developed a serious condition called lactic acidosis. Lactic acidosis is caused by a buildup of lactic acid in the blood. This happens more often in people with kidney problems. Most people with kidney problems should not take Metformin Hydrochloride Tablets USP. (See "What are the side effects of Metformin Hydrochloride Tablets USP?")
Who should not take Metformin Hydrochloride Tablets USP?
Some conditions increase your chance of getting lactic acidosis, or cause other problems if you take either of these medicines. Most of the conditions listed below can increase your chance of getting lactic acidosis.
Do not take Metformin Hydrochloride Tablets USP if you:
Tell your doctor if you are pregnant or plan to become pregnant. Metformin Hydrochloride Tablets USP may not be right for you. Talk with your doctor about your choices. You should also discuss your choices with your doctor if you are nursing a child.
Can Metformin Hydrochloride Tablets USP be used in children?
Metformin Hydrochloride Tablets USP has been shown to effectively lower glucose levels in children (ages 10 to 16 years) with type 2 diabetes. Metformin Hydrochloride Tablets USP has not been studied in children younger than 10 years old. Metformin Hydrochloride Tablets USP has not been studied in combination with other oral glucose-control medicines or insulin in children. If you have any questions about the use of Metformin Hydrochloride Tablets USP in children, talk with your doctor or other healthcare provider.
How should I take Metformin Hydrochloride Tablets USP?
Your doctor will tell you how much medicine to take and when to take it. You will probably start out with a low dose of the medicine. Your doctor may slowly increase your dose until your blood sugar is better controlled. You should take Metformin Hydrochloride Tablets USP with meals.
Your doctor may have you take other medicines along with Metformin Hydrochloride Tablets USP to control your blood sugar. These medicines may include insulin shots. Taking Metformin Hydrochloride Tablets USP with insulin may help you better control your blood sugar while reducing the insulin dose.
Continue your exercise and diet program and test your blood sugar regularly while taking Metformin Hydrochloride Tablets USP. Your doctor will monitor your diabetes and may perform blood tests on you from time to time to make sure your kidneys and your liver are functioning normally. There is no evidence that Metformin Hydrochloride Tablets USP causes harm to the liver or kidneys.
Tell your doctor if you:
What should I avoid while taking Metformin Hydrochloride Tablets USP?
Do not drink a lot of alcoholic drinks while taking Metformin Hydrochloride Tablets USP. This means you should not binge drink for short periods, and you should not drink a lot of alcohol on a regular basis. Alcohol can increase the chance of getting lactic acidosis.
What are the side effects of Metformin Hydrochloride Tablets USP?
Lactic Acidosis . In rare cases, Metformin Hydrochloride Tablets USP can cause a serious side effect called lactic acidosis. This is caused by a buildup of lactic acid in your blood. This buildup can cause serious damage. Lactic acidosis caused by Metformin Hydrochloride Tablets USP is rare and has occurred mostly in people whose kidneys were not working normally. Lactic acidosis has been reported in about one in 33,000 patients taking Metformin Hydrochloride Tablets USP over the course of a year. Although rare, if lactic acidosis does occur, it can be fatal in up to half the people who develop it.
It is also important for your liver to be working normally when you take Metformin Hydrochloride Tablets USP. Your liver helps remove lactic acid from your blood.
Make sure you tell your doctor before you use Metformin Hydrochloride Tablets USP if you have kidney or liver problems. You should also stop using Metformin Hydrochloride Tablets USP and call your doctor right away if you have signs of lactic acidosis. Lactic acidosis is a medical emergency that must be treated in a hospital.
Signs of lactic acidosis are:
If your medical condition suddenly changes, stop taking Metformin Hydrochloride Tablets USP and call your doctor right away. This may be a sign of lactic acidosis or another serious side effect.
Other Side Effects. Common side effects of Metformin Hydrochloride Tablets USP include diarrhea, nausea, and upset stomach. These side effects generally go away after you take the medicine for a while. Taking your medicine with meals can help reduce these side effects. Tell your doctor if the side effects bother you a lot, last for more than a few weeks, come back after they’ve gone away, or start later in therapy. You may need a lower dose or need to stop taking the medicine for a short period or for good.
About 3 out of every 100 people who take Metformin Hydrochloride Tablets USP have an unpleasant metallic taste when they start taking the medicine. It lasts for a short time.
Metformin Hydrochloride Tablets USP rarely cause hypoglycemia (low blood sugar) by themselves. However, hypoglycemia can happen if you do not eat enough, if you drink alcohol, or if you take other medicines to lower blood sugar.
General advice about prescription medicines
If you have questions or problems, talk with your doctor or other healthcare provider. You can ask your doctor or pharmacist for the information about Metformin Hydrochloride Tablets USP that is written for healthcare professionals. Medicines are sometimes prescribed for purposes other than those listed in a patient information leaflet. Do not use Metformin Hydrochloride Tablets USP for a condition for which it was not prescribed. Do not share your medicine with other people.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Distributed by:
New Horizon Rx Group, LLC
Kenner, LA 70062
1-800-465-5545
Manufactured by:
Granules India Limited
Ranga Reddy Dist., India 500-043 AP
Rev. 11/13
Photos of the product and/or packaging supplied by the manufacturer.
Metformin is an antihyperglycemic agent which improves glucose tolerance in patients with type 2 diabetes, lowering both basal and postprandial plasma glucose. Its pharmacologic mechanisms of action are different from other classes of oral antihyperglycemic agents. Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization. Unlike sulfonylureas, metformin does not produce hypoglycemia in either patients with type 2 diabetes or normal subjects (except in special circumstances, see PRECAUTIONS) and does not cause hyperinsulinemia. With metformin therapy, insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may actually decrease.
Absorption and Bioavailability
The absolute bioavailability of a Metformin Hydrochloride 500 mg tablet given under fasting conditions is approximately 50% to 60%. Studies using single oral doses of Metformin Hydrochloride 500 mg to 1500 mg, and 850 mg to 2550 mg, indicate that there is a lack of dose proportionality with increasing doses, which is due to decreased absorption rather than an alteration in elimination. Food decreases the extent of and slightly delays the absorption of metformin, as shown by approximately a 40% lower mean peak plasma concentration (Cmax), a 25% lower area under the plasma concentration versus time curve (AUC), and a 35-minute prolongation of time to peak plasma concentration (Tmax) following administration of a single 850 mg tablet of metformin with food, compared to the same tablet strength administered fasting. The clinical relevance of these decreases is unknown.
Distribution
The apparent volume of distribution (V/F) of metformin following single oral doses of Metformin Hydrochloride Tablets USP 850 mg averaged 654 ± 358 L. Metformin is negligibly bound to plasma proteins, in contrast to sulfonylureas, which are more than 90% protein bound. Metformin partitions into erythrocytes, most likely as a function of time. At usual clinical doses and dosing schedules of Metformin Hydrochloride Tablets USP, steady state plasma concentrations of metformin are reached within 24 to 48 hours and are generally <1 mcg/mL. During controlled clinical trials of Metformin Hydrochloride Tablets USP, maximum metformin plasma levels did not exceed 5 mcg/mL, even at maximum doses.
Metabolism and Elimination
Intravenous single-dose studies in normal subjects demonstrate that metformin is excreted unchanged in the urine and does not undergo hepatic metabolism (no metabolites have been identified in humans) nor biliary excretion. Renal clearance (see Table 1) is approximately 3.5 times greater than creatinine clearance, which indicates that tubular secretion is the major route of metformin elimination. Following oral administration, approximately 90% of the absorbed drug is eliminated via the renal route within the first 24 hours, with a plasma elimination half-life of approximately 6.2 hours. In blood, the elimination half-life is approximately 17.6 hours, suggesting that the erythrocyte mass may be a compartment of distribution.
Long-term carcinogenicity studies have been performed in rats (dosing duration of 104 weeks) and mice (dosing duration of 91 weeks) at doses up to and including 900 mg/kg/day and 1500 mg/kg/day, respectively. These doses are both approximately four times the maximum recommended human daily dose of 2000 mg based on body surface area comparisons. No evidence of carcinogenicity with metformin was found in either male or female mice. Similarly, there was no tumorigenic potential observed with metformin in male rats. There was, however, an increased incidence of benign stromal uterine polyps in female rats treated with 900 mg/kg/day.
There was no evidence of a mutagenic potential of metformin in the following in vitro tests: Ames test (S. typhimurium), gene mutation test (mouse lymphoma cells), or chromosomal aberrations test (human lymphocytes). Results in the in vivo mouse micronucleus test were also negative.
Fertility of male or female rats was unaffected by metformin when administered at doses as high as 600 mg/kg/day, which is approximately three times the maximum recommended human daily dose based on body surface area comparisons.
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