Glimepiride

Uses and Indications

Glimepiride tablets are indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. This medication is classified as a sulfonylurea.

Limitations of Use

Glimepiride is not indicated for the treatment of type 1 diabetes mellitus or diabetic ketoacidosis.

Dosage and Administration

The recommended starting dose of Glimepiride is 1 mg or 2 mg administered once daily. Dosing may be increased in increments of 1 mg or 2 mg, no more frequently than every 1 to 2 weeks, based on the patient's glycemic response. The maximum recommended dose is 8 mg once daily.

Glimepiride should be taken with breakfast or the first meal of the day to enhance its efficacy. For patients at increased risk of hypoglycemia, such as the elderly or those with renal impairment, it is advised to initiate treatment with a 1 mg starting dose and to titrate slowly.

Contraindications

Use of glimepiride is contraindicated in individuals with hypersensitivity to glimepiride or any of the product’s ingredients. Additionally, it is contraindicated in patients with hypersensitivity to sulfonamide derivatives.

Warnings and Precautions

Hypoglycemia Glimepiride may cause severe hypoglycemia. It is essential to ensure proper patient selection, dosing, and instructions, particularly for at-risk populations such as the elderly and those with renal impairment. Caution is advised when glimepiride is used in conjunction with other anti-diabetic medications.

Hypersensitivity Reactions Postmarketing reports indicate that glimepiride can lead to hypersensitivity reactions, including anaphylaxis, angioedema, and Stevens-Johnson Syndrome. If a hypersensitivity reaction is suspected, glimepiride should be promptly discontinued, and other potential causes for the reaction should be assessed. Appropriate monitoring and alternative diabetes treatment should be instituted.

Hemolytic Anemia Hemolytic anemia may occur in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency. In such cases, a non-sulfonylurea alternative should be considered.

Cardiovascular Risks There is a potential increased risk of cardiovascular mortality associated with sulfonylureas, including glimepiride. Patients should be informed of the risks, benefits, and available treatment alternatives.

Macrovascular Outcomes Clinical studies have not established conclusive evidence of macrovascular risk reduction with glimepiride or any other anti-diabetic drug.

Monitoring Requirements No specific laboratory tests or monitoring requirements are explicitly listed in the provided data.

Emergency Medical Help No specific instructions for obtaining emergency medical help are provided.

Discontinuation Instructions If a hypersensitivity reaction is suspected, glimepiride should be promptly discontinued, and other potential causes for the reaction should be assessed.

Side Effects

Common adverse reactions associated with glimepiride include:

• Hypoglycemia: This may be severe and requires careful patient selection, dosing, and instructions, particularly in at-risk populations such as the elderly and those with renal impairment, as well as when used in conjunction with other anti-diabetic medications.

• Headache

• Nausea

• Dizziness

Serious adverse reactions include:

• Hypersensitivity Reactions: Postmarketing reports indicate occurrences of anaphylaxis, angioedema, and Stevens-Johnson Syndrome. If a hypersensitivity reaction is suspected, glimepiride should be promptly discontinued, and alternative diabetes treatment should be initiated.

• Hemolytic Anemia: This condition can occur in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency. In such cases, a non-sulfonylurea alternative should be considered.

• Potential Increased Risk of Cardiovascular Mortality with Sulfonylureas: Patients should be informed of the associated risks, benefits, and treatment alternatives.

• Macrovascular Outcomes: There are no clinical studies that establish conclusive evidence of macrovascular risk reduction with glimepiride or any other anti-diabetic drug.

Additional important notes include:

• Hypoglycemic Events in Pediatric Patients: Documented by blood glucose values <36 mg/dL, these events were observed in 4% of pediatric patients treated with glimepiride, compared to 1% in those treated with metformin. One patient in each treatment group experienced a severe hypoglycemic episode, as determined by the investigator based on observed signs and symptoms.

• Hypersensitivity: Patients may exhibit hypersensitivity to glimepiride or any of its ingredients, as well as to sulfonamide derivatives.

• Overdosage: An overdosage of glimepiride can lead to severe hypoglycemia. Mild episodes can be treated with oral glucose, while severe reactions require immediate medical attention, including glucagon or intravenous glucose administration. Continuous observation and additional carbohydrate intake may be necessary due to the potential for recurrent hypoglycemia after apparent clinical recovery.

• Elderly Patients: Greater sensitivity in older individuals cannot be ruled out. Caution is advised when initiating or increasing the dose of glimepiride in this population, particularly due to the likelihood of renal impairment and the difficulty in recognizing hypoglycemia.

• Pregnancy and Neonatal Risks: Glimepiride should be discontinued at least two weeks before the expected delivery date to mitigate risks of neonatal adverse reactions, including respiratory distress, hypoglycemia, birth injury, and being large for gestational age. Prolonged severe hypoglycemia lasting 4 to 10 days has been reported in neonates born to mothers receiving sulfonylureas at the time of delivery. Breastfed infants of lactating women using glimepiride should be monitored for symptoms of hypoglycemia.

Drug Interactions

Certain medications may influence glucose metabolism, necessitating dose adjustments of glimepiride and close monitoring of blood glucose levels.

Pharmacodynamic Interactions

• Miconazole: The concomitant use of glimepiride and oral miconazole can lead to severe hypoglycemia.

Pharmacokinetic Interactions

• Cytochrome P450 2C9: Inhibitors and inducers of cytochrome P450 2C9 may alter glimepiride plasma concentrations, thereby affecting glycemic control.

• Colesevelam: Co-administration with colesevelam may reduce the absorption of glimepiride. It is recommended that glimepiride be administered at least 4 hours prior to colesevelam to mitigate this interaction.

Overall, careful monitoring and potential dose adjustments are advised when glimepiride is used in conjunction with these medications.

Pediatric Use

Glimepiride is not recommended in pediatric patients due to its adverse effects on body weight and the risk of hypoglycemia.

The pharmacokinetics of a 1 mg single dose of glimepiride was evaluated in 30 patients with type 2 diabetes aged 10 to 17 years. The safety and efficacy of glimepiride were assessed in a single-blind, 24-week trial that randomized 272 patients aged 8 to 17 years with type 2 diabetes to receive either glimepiride (n=135) or metformin (n=137).

In this study, glimepiride was initiated at a dose of 1 mg, which was then titrated up to 2, 4, or 8 mg, with a mean last dose of 4 mg by Week 12. Hypoglycemic events, defined by blood glucose values <36 mg/dL, were observed in 4% of pediatric patients treated with glimepiride, compared to 1% in those treated with metformin. Additionally, one patient in each treatment group experienced a severe hypoglycemic episode, as determined by the investigator based on observed signs and symptoms.

Geriatric Use

In clinical trials of glimepiride, 30% of patients were aged 65 years or older. No overall differences in safety or effectiveness were observed between geriatric patients and younger patients; however, greater sensitivity in some elderly individuals cannot be ruled out. Pharmacokinetic studies indicated no significant differences between patients with type 2 diabetes aged 65 years or younger and those older than 65 years.

Glimepiride is substantially excreted by the kidneys, and elderly patients are more likely to experience renal impairment. Additionally, hypoglycemia may be difficult to recognize in this population. Therefore, caution is advised when initiating glimepiride or increasing the dose in geriatric patients. Regular monitoring for signs of hypoglycemia and renal function is recommended to ensure safe and effective use in this demographic.

Pregnancy

Available data from a limited number of published studies and postmarketing experience with glimepiride use in pregnancy have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal outcomes. Glimepiride is classified as Pregnancy Category C, indicating that there are no adequate and well-controlled studies in pregnant women.

Sulfonylureas, including glimepiride, cross the placenta and have been associated with neonatal adverse reactions such as hypoglycemia. Prolonged severe hypoglycemia lasting 4 to 10 days has been reported in neonates born to mothers receiving a sulfonylurea at the time of delivery. Therefore, glimepiride should be discontinued at least two weeks before the expected delivery date to mitigate these risks.

Poorly controlled diabetes during pregnancy poses significant risks to both the mother and fetus. The estimated background risk of major birth defects is 6% to 10% in women with pregestational diabetes and an HbA1c >7%, increasing to as high as 20% to 25% in women with an HbA1c >10%. The background risk of miscarriage in this population is unknown. In the general U.S. population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Maternal complications associated with poorly controlled diabetes include diabetic ketoacidosis, preeclampsia, spontaneous abortions, preterm delivery, and delivery complications. Fetal risks include major birth defects, stillbirth, and macrosomia-related morbidity. Neonates of women with gestational diabetes treated with sulfonylureas may be at increased risk for neonatal intensive care admission and may experience respiratory distress, hypoglycemia, birth injury, and be large for gestational age.

In animal studies, there was no increase in congenital anomalies; however, an increase in fetal deaths was observed in rats and rabbits at glimepiride doses 50 times and 0.1 times the maximum recommended human dose, respectively. This fetotoxicity was noted only at doses that induced maternal hypoglycemia and is believed to be directly related to the pharmacologic action of glimepiride.

Given these considerations, glimepiride should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is essential to maintain blood glucose levels as close to normal as possible during pregnancy to reduce the incidence of congenital abnormalities. Newborns should be observed for symptoms of hypoglycemia and respiratory distress, and managed accordingly.

Lactation

There is limited information regarding the use of glimepiride in lactating mothers and its effects on breast milk. It is not known whether glimepiride is excreted in human milk; however, studies in rats have shown significant concentrations of glimepiride in both breast milk and the serum of the pups. Offspring of rats exposed to high levels of glimepiride during pregnancy and lactation exhibited skeletal deformities, including shortening, thickening, and bending of the humerus, attributed to nursing from mothers treated with glimepiride.

Given the potential for hypoglycemia in breastfed infants, it is recommended that lactating mothers using glimepiride closely monitor their infants for signs of hypoglycemia, which may include jitters, cyanosis, apnea, hypothermia, excessive sleepiness, poor feeding, and seizures. The developmental and health benefits of breastfeeding should be weighed against the mother's clinical need for glimepiride and any potential adverse effects on the breastfed child.

Additionally, glimepiride should be discontinued at least two weeks prior to the expected delivery due to the risk of prolonged severe hypoglycemia in neonates born to mothers receiving sulfonylureas at the time of delivery. Newborns of women with gestational diabetes treated with sulfonylureas may be at increased risk for complications, including respiratory distress and birth injury, and should be observed accordingly. Decisions regarding the continuation of breastfeeding or glimepiride therapy should be made on a case-by-case basis, considering the importance of the medication to the mother’s health.

Renal Impairment

Patients with renal impairment require careful consideration when prescribed glimepiride. To minimize the risk of hypoglycemia, the recommended starting dose for patients with type 2 diabetes and renal impairment is 1 mg daily. This adjustment is crucial, particularly for those with a baseline creatinine clearance ranging from 10 to 60 mL/min.

Clinical studies have demonstrated that the pharmacokinetics of glimepiride are altered in patients with reduced kidney function. Specifically, the relative total clearance of glimepiride increases as kidney function declines, while the elimination of its major metabolites is significantly reduced. This necessitates close monitoring of blood glucose levels and potential dose adjustments to avoid severe hypoglycemic events.

Healthcare providers should ensure proper patient selection and provide clear dosing instructions, especially for at-risk populations such as the elderly and those with renal impairment. Regular assessment of renal function is recommended to guide ongoing treatment decisions and ensure patient safety.

Hepatic Impairment

Patients with hepatic impairment have no specific dosage adjustments, special monitoring requirements, or precautions outlined for the use of Glimepiride. The available data does not provide guidance on the management of this medication in individuals with liver problems. Therefore, healthcare providers should exercise caution and consider individual patient factors when prescribing Glimepiride to patients with hepatic impairment. Regular monitoring of blood glucose levels and liver function tests may be prudent in this population, although specific recommendations are not provided in the labeling.

Overdosage

An overdosage of glimepiride, similar to other sulfonylureas, can lead to severe hypoglycemia, which is a medical emergency requiring immediate intervention. Symptoms of hypoglycemia may include confusion, dizziness, sweating, and in severe cases, coma, seizures, or neurological impairment.

For mild episodes of hypoglycemia, treatment with oral glucose is recommended. In cases of severe hypoglycemia, administration of glucagon or intravenous glucose is necessary to restore normal blood glucose levels.

It is crucial to monitor patients closely following an overdose, as hypoglycemia may recur after initial treatment and apparent clinical recovery. Continued observation and additional carbohydrate intake may be required, particularly for at-risk populations such as the elderly and individuals with renal impairment, who should be monitored more closely for severe hypoglycemic reactions.

Nonclinical Toxicology

Carcinogenesis

Studies conducted in rats at doses of up to 5000 parts per million (ppm) in complete feed, approximately 340 times the maximum recommended human dose based on surface area, for a duration of 30 months, demonstrated no evidence of carcinogenesis. In contrast, administration of glimepiride in mice over a 24-month period resulted in a dose-related increase in benign pancreatic adenoma formation, which was attributed to chronic pancreatic stimulation. Notably, no adenoma formation was observed in mice at a dose of 320 ppm in complete feed, or 46 to 54 mg/kg body weight/day, which is at least 28 times the maximum human recommended dose of 8 mg once daily based on surface area.

Mutagenesis

Glimepiride was evaluated for mutagenic potential in a comprehensive battery of in vitro and in vivo mutagenicity studies, including the Ames test, somatic cell mutation assays, chromosomal aberration tests, unscheduled DNA synthesis, and the mouse micronucleus test. The results indicated that glimepiride is non-mutagenic.

Impairment of Fertility

The effects of glimepiride on fertility were assessed in male mice exposed to doses up to 2500 mg/kg body weight, which is greater than 1,500 times the maximum recommended human dose based on surface area. No adverse effects on male fertility were observed. Similarly, glimepiride did not affect the fertility of male and female rats administered doses up to 4000 mg/kg body weight, approximately 4,000 times the maximum recommended human dose based on surface area.

Teratogenic Effects

No information regarding teratogenic effects of glimepiride is provided in the available data. Additionally, there are reports of prolonged severe hypoglycemia (lasting 4 to 10 days) in neonates born to mothers who received a sulfonylurea at the time of delivery, although this is not directly related to the teratogenic potential of glimepiride.

Storage and Handling

Glimepiride is supplied in tablet form. It should be stored at a temperature range of 20° to 25°C (68° to 77°F), in accordance with USP Controlled Room Temperature guidelines.

The product must be dispensed in well-closed containers equipped with safety closures to ensure proper handling and storage. It is important to note that if the blister packaging is torn or broken, the product should not be used.

For specific packaging configurations, Glimepiride may also be dispensed in unit dose packages for institutional use only.