Short-term comparison of once- versus twice-daily administration of glimepiride in patients with non-insulin-dependent diabetes mellitus

Investigation of the synergistic effect of glimepiride and rosuvastatin on alloxan-induced diabetic rat

Purpose

Diabetes mellitus is characterized by having a multitude of life-threatening secondary complications, particularly dyslipidemia, which ultimately leads to the development of comorbid diseases, such as cardiovascular diseases. This research work was designed to investigate the synergistic effect of glimepiride (1 mg/kg b.w.) and rosuvastatin (10 mg /kg b.w.) on alloxan-induced diabetic rats having dyslipidemia.

Methods

Diabetes was induced by injecting alloxan (120 mg/kg b.w.) intraperitoneally. The experiment was conducted to determine the level of blood glucose, HbA1c, lipid profile, and body weight variation of rats.

Results

This study's outcomes suggested that the combination therapy showed more statistically significant effect on blood glucose level, HbA1c level, lipid profile, and body weight variation than any single therapy. While the glimepiride monotherapy showed a statistically considerable effect on blood glucose level, HbA1c level, and body weight variation, the rosuvastatin treated group gave statistically non-significant effect on these parameters except body weight variation, which was found as downward trend. In addition, the rosuvastatin treated group showed a healthy lipid profile compared to glimepiride treated group.

Conclusions

Concluding the results of this study, it can be said that the treatment of glimepiride in combination with rosuvastatin may be more efficacious than monotherapy for preventing diabetes in rats with dyslipidemia.

In-vitro and in-vivo performance of locally manufactured glimepiride tablet generics compared to the innovator (Amaryl®) tablets

Both physicians and patients in Egypt often express concern as to the clinical efficacy of locally manufactured glimepiride tablet generics whenever adequate control of blood sugar is not achieved with these products. The present study addresses this issue. The pharmaceutical quality of four glimepiride 3 mg tablet generics purchased in Egypt from local pharmacies was assessed relative to the innovator product (Amaryl^®), 3 mg tablets. Uniformity of Content, dissolution rate, disintegration time and hardness were determined. Products were subjected to a 6-month stability study under stress condition (40 °c/75%RH). The same brands were evaluated in vivo in a clinical study conducted in the Main Alexandria University Hospital involving 100 patients (20 patients per brand including innovator). Patients recruited were newly diagnosed type II diabetics. Glimepiride tablets were used as a monotherapy. Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1C) were measured over a period of 3 months. The results indicated differences (p ≤ .05) in the in vitro and in vivo performance of the tested products; innovator and tested generics substitution was not evident. The stability study indicated that the tablets were prone to deterioration in their physical characteristics, particularly dissolution profiles, upon storage of blisters in a hot humid climate. In vitro/in vivo correlations were investigated seeking to identify an in vitro test to serve as a performance indicator for glimepiride tablets in the post-marketing period. The similarity factor (f₂) of the dissolution data proved to be a good indicator of in vivo performance of the tablets.

Major Pathophysiology in Prediabetes and Type 2 Diabetes: Decreased Insulin in Lean and Insulin Resistance in Obese

CONTEXT

Lowering of body mass index (BMI) to ≥25 kg/m2 as obesity by ADA suggests insulin resistance as a major mechanism of impaired glucose metabolism (IGM) in Asians. However, glimepiride, an insulin secretagogue, delayed onset of type 2 diabetes (DM2) from prediabetes (PreDM), indicating decreased insulin secretion (IS) as a major factor in lean (L; BMI < 27 kg/m2) subjects with IGM.

OBJECTIVE

Assessment of IS and insulin resistance (IR) in L and obese (Ob; BMI ≥ 27 kg/m2) subjects with euglycemia (N), PreDM, and new onset DM2.

SUBJECTS

Seventy-five men and 45 women ages 36 to 75 years were divided into six groups: LN, LPreDM, LDM2, ObN, ObPreDM, and ObDM2.

METHODS

Determination of IS by insulinogenic indices (I/G) at fasting (FI/FG), first phase (∆I/∆G), and cumulative responses over 2 hours of OGTT (CRI/CRG), and IR by FIXFG, ∆IX∆G, and CRIXCRG. Changes in IS and IR for PreDM and DM2 were calculated as % fall and % rise, respectively, from levels in N.

RESULTS

All indices of IS and IR were lower (P < 0.05) in L than corresponding Ob groups (P < 0.05). Moreover, decline in IS and rise in IR were progressive from N to PreDM (P < 0.05) and DM2 (P < 0.05) in both groups. However, the declines in IS were greater (P < 0.05) than rises in IR in LPreDM and LDM2. Whereas, the rises in IR were higher (P < 0.05) than declines in IS in ObPreDM and ObDM2.

CONCLUSION

In L, major mechanism of IGM is declining IS and not rising IR documented among Ob.

[A case of hypoglycemia caused by the accidental ingestion of glimepiride in an elderly dementia patient diagnosed based on the serum glimepiride concentration]

A 77-year-old man being treated for Alzheimer-type dementia and an old cerebral infarction was admitted to our hospital due to disturbance of consciousness. The patient's Mini-mental State Examination and Hasegawa Dementia Scale scores were 23 and 17 points, respectively. His blood glucose level was low (18 mg/dl), with a relatively high insulin level (15.2 μU/ml). Computed tomography and an 18-hour fasting test showed no signs of insulinoma. Since his wife had been taking medications for dementia and diabetes, including Glimepiride, we considered the possibility that he may have taken glimepiride by mistake. Five months later, he was admitted again due to severe hypoglycemia with a relatively high insulin level (23.4 μU/ml). More than 660 g of glucose and 100 mg of hydrocortisone were administered, and the hypoglycemia resolved approximately 24 hours after admission. Again, there were no signs of insulinoma. We asked Sanofi-Aventis to measure the level of glimepiride in a blood sample obtained six hours after admission. Glimepiride was detected at a concentration of 24.48 ng/ml, which roughly corresponded to the accidental ingestion of 6 mg of the drug. We were later informed by the patient's home doctor that he had visited the emergency department of another prefecture hospital with the same symptoms. Thereafter, the couple received counseling by their home doctor, and the hypoglycemia has not recurred since. Given the increase in the number of elderly households, an increase in the number of episodes of accidental ingestion of medicine is expected. Clinicians should be aware of the potential for accidental exposure to drugs prescribed to other family members especially, in elderly patients.

Glimepiride: evidence-based facts, trends, and observations (GIFTS). [corrected]

Type 2 diabetes mellitus is characterized by insulin resistance and progressive β cell failure; therefore, β cell secretagogues are useful for achieving sufficient glycemic control. Glimepiride is a second-generation sulfonylurea that stimulates pancreatic β cells to release insulin. Additionally, is has been shown to work via several extra pancreatic mechanisms. It is administered as monotherapy in patients with type 2 diabetes mellitus in whom glycemic control is not achieved by dietary and lifestyle modifications. It can also be combined with other antihyperglycemic agents, including metformin and insulin, in patients who are not adequately controlled by sulfonylureas alone. The effective dosage range is 1 to 8 mg/day; however, there is no significant difference between 4 and 8 mg/day, but it should be used with caution in the elderly and in patients with renal or hepatic disease. In clinical studies, glimepiride was generally associated with lower risk of hypoglycemia and less weight gain compared to other sulfonylureas. Glimepiride use may be safer in patients with cardiovascular disease because of its lack of detrimental effects on ischemic preconditioning. It is effective in reducing fasting plasma glucose, post-prandial glucose, and glycosylated hemoglobin levels and is a useful, cost-effective treatment option for managing type 2 diabetes mellitus.

Type 2 diabetes in pediatrics and adults: thoughts from a clinical pharmacology perspective

Type 2 diabetes results when insulin secretion is unable to keep the plasma glucose levels as per acceptable range. This leads to chronic hyperglycemia and its associated microvascular complications such as renal impairment (diabetic nephropathy), retinal abnormalities (diabetic retinopathy), and autonomic, sensory, and motor neuropathies (diabetic neuropathy) and macrovascular disease. Historically, type 2 diabetes is well known as an adult-onset disease; however, lately, the incidence of the disease is reported to be increasing in children. Despite the wealth of information concerning type 2 diabetes in adults, data unique to the pediatric age group regarding the pathophysiology and therapy for type 2 diabetes are limited. For treatment in pediatric type 2 diabetes, metformin and insulin are the only antidiabetic agents approved currently. There are data of use of other oral antidiabetic drugs including glimepiride, rosiglitazone, and glyburide (in combination with metformin) in pediatric patients; however, formal clinical trials to establish the safety and efficacy have not been conducted. This review will compare the clinical pharmacology aspects of the oral type 2 diabetic drugs in pediatric and adult populations in order to determine any differences between the two patient groups.

The role of glimepiride in the treatment of type 2 diabetes mellitus

IMPORTANCE OF THE FIELD

Type 2 diabetes mellitus (T2DM) is increasingly prevalent throughout the world; controlling glycemia is an important part of preventing serious complications of diabetes. Sulfonylureas have been used in the treatment of type 2 diabetes for many years.

AREAS COVERED IN THIS REVIEW

This article reviews the pharmacological and clinical aspects of glimepiride, a second-generation sulfonylurea. Literature search was conducted in PubMed, and articles selected for relevance to pharmacology or clinical efficacy data from 1994 to 2009, with older references sought as indicated.

WHAT THE READER WILL GAIN

Pharmacology of glimepiride, data regarding clinical efficacy, key comparisons to other agents and emerging concepts related to glimepiride are discussed.

TAKE HOME MESSAGE

Therapy with glimepiride improves the relative insulin secretory deficit found in T2DM, has antihyperglycemic efficacy equal to other secretagogues with reduced potential for hypoglycemia and may have additional actions contributing to glycemic control in T2DM.

Cardiovascular outcomes in trials of oral diabetes medications: a systematic review

BACKGROUND

A wide variety of oral diabetes medications are currently available for the treatment of type 2 diabetes mellitus, but it is unclear how these agents compare with respect to long-term cardiovascular risk. Our objective was to systematically examine the peer-reviewed literature on the cardiovascular risk associated with oral agents (second-generation sulfonylureas, biguanides, thiazolidinediones, and meglitinides) for treating adults with type 2 diabetes.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials, from inception through January 19, 2006. Forty publications of controlled trials that reported information on cardiovascular events (primarily myocardial infarction and stroke) met our inclusion criteria. Using standardized protocols, 2 reviewers serially abstracted data from each article. Trials were first described qualitatively. For comparisons with 4 or more independent trials, results were pooled quantitatively using the Mantel-Haenszel method. Results are presented as odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

RESULTS

Treatment with metformin hydrochloride was associated with a decreased risk of cardiovascular mortality (pooled OR, 0.74; 95% CI, 0.62-0.89) compared with any other oral diabetes agent or placebo; the results for cardiovascular morbidity and all-cause mortality were similar but not statistically significant. No other significant associations of oral diabetes agents with fatal or nonfatal cardiovascular disease or all-cause mortality were observed. When compared with any other agent or placebo, rosiglitazone was the only diabetes agent associated with an increased risk of cardiovascular morbidity or mortality, but this result was not statistically significant (OR, 1.68; 95% CI, 0.92-3.06).

CONCLUSIONS

Meta-analysis suggested that, compared with other oral diabetes agents and placebo, metformin was moderately protective and rosiglitazone possibly harmful, but lack of power prohibited firmer conclusions. Larger, long-term studies taken to hard end points and better reporting of cardiovascular events in short-term studies will be required to draw firm conclusions about major clinical benefits and risks related to oral diabetes agents.

Pharmacokinetics and pharmacodynamics of glimepiride in type 2 diabetic patients: compared effects of once- versus twice-daily dosing

To compare the pharmacokinetic and pharmacodynamic effects of glimepiride between once- and twice-daily dosing in type 2 diabetic patients. Eight Japanese type 2 diabetic patients, who had been treated with 2 mg glimepiride alone over 4 weeks (age 40-70, body mass index <or=25 kg/m2, hemoglobin A 1C<8.0%), were randomly assigned to the crossover study with glimepiride 2 mg once-daily and 1 mg twice-daily for 4 weeks for each regime. Serum concentrations of glimepiride, plasma glucose, insulin and C-peptide were measured over 24 h at the fixed time intervals on the last day of each crossover period, and HbA 1C was measured at the same day. Pharmacokinetic profiles in two regimens were different to each others; a single peak of serum glimepiride concentration was observed in once-daily, and double peaks in twice-daily dosing. Drug concentration increased immediately, and peaked at 2 h after administration irrespective of dosage. Cmax value in once-daily dose was higher than those in twice-daily doses. AUC values were not different between two regimens. Pharmacodynamic profiles for plasma glucoses, serum insulin and C-peptide showed no statistically significant differences between two regimens, and parameters were not different each other. Analyses of adverse events and laboratory data demonstrated a favorable safety profile of glimepiride. The present results suggest that glimepiride may be suitable for once-daily dosing with respect to clinical usefulness.

Pioglitazone plus glimepiride: a promising alternative in metabolic control

Current approaches to pharmacotherapy of type 2 diabetes focus on two key aspects of hyperglycaemia - insulin secretory dysfunction and insulin resistance. Combining drugs that target both these defects via different mechanisms of action improves long-term glycaemic control and offers a number of additional benefits. A fixed-dose combination of pioglitazone and glimepiride in a single tablet is now available in the US (Duetact(TM)). Both pioglitazone and glimepiride are glucose-lowering agents with distinct mechanisms of action. Pioglitazone is a potent and selective peroxisome proliferator-activated receptor-gamma agonist that improves whole-body insulin sensitivity and augments hepatic glucose uptake. On the other hand, glimepiride acts by releasing insulin from pancreatic beta-cells and improves both first and second phases of insulin secretion. These two therapies have been shown to act synergistically to treat type 2 diabetes - glimepiride therapy achieves rapid reductions in glycated haemaglobin (HbA(1c)), whereas pioglitazone sustains glycaemic control in the longer term. Furthermore, pioglitazone and glimepiride affect a number of pleiotropic markers. In particular, pioglitazone has beneficial effects on the atherogenic diabetic dyslipidaemia that are greater than those seen with rosiglitazone and other oral glucose-lowering agents. This advantage is also seen when comparing pioglitazone and rosiglitazone in combination with glimepiride. In addition, pioglitazone also improves a number of atherosclerotic risk markers that appear to translate into clinical benefits on macrovascular outcomes. Glimepiride may also improve several atherosclerotic risk markers and lipoproteins. This review discusses the potential benefits of combining pioglitazone plus glimepiride on patient compliance, targeting the dual effects of insulin resistance and beta-cell dysfunction and affecting a number of metabolic and cardiovascular parameters.

Are sulfonylureas passé?

Sulfonylureas and similarly acting rapid insulin secretagogues have long been available to manage type 2 diabetes. These agents have a well understood mechanism of action and are in large part well tolerated. However, sulfonylurea therapy is unlikely to sustain adequate long-term glycemic control and has potential side effects, including hypoglycemia and weight gain. Additional concerns exist regarding detrimental effects of certain sulfonylureas on ischemic preconditioning and cardiac outcomes. Fortunately, newer agents such as glimepiride appear less likely to adversely affect the myocardium. These agents can often be used successfully as one component of combination therapy for diabetes management.

Improved liquid chromatographic tandem mass spectrometric determination and pharmacokinetic study of glimepiride in human plasma

An improved liquid chromatographic tandem mass spectrometric method for the determination of glimepiride in human plasma has been developed and fully validated. The article describes in detail the bioanalytical procedure and summarizes the validation results obtained. The samples were extracted using liquid--liquid extraction with a mixture of 1-chlorobutane-isopropanol-ethyl acetate (88:2:10, v/v/v). The chromatographic separation was performed on a reversed-phase Hypersil ODScolumn (250 x 4.6 mm i.d.; 5 microm particle size) using a mobile phase consisting of formic acid 0.05 M-acetonitrile (28:72, v/v), pumped at a flow rate of 0.3 ml min(-1) heated to 25 degrees C. The analytes were detected using an API 3000 triple quadrupole mass spectrometer with positive electrospray ionization in multiple reaction monitoring mode. Tandem mass spectrometric detection enabled the quantitation of glimepiride down to 0.50 ng mL(-1). Calibration graphs were linear (r better than 0.998, n=1), in concentration range 0.50--1000 ng mL(-1), and the intra- and inter- day RSD values were less than 10.37 and 11.55% for glimepiride. The method was successfully applied to a kinetic study in order to assess the main pharmacokinetic parameters of glimepiride.

The role of glimepiride in the effective management of Type 2 diabetes

Type 2 diabetes mellitus, a disorder of impaired insulin secretion and insulin resistance, has reached epidemic proportions. The effective management of Type 2 diabetes is of vital concern to clinicians. The identification of high-risk individuals and lifestyle management can help control diabetes; however, most patients require pharmacologic intervention. The goals of pharmacologic therapy are to achieve adequate glycemic control while avoiding hypoglycemia and weight gain and to minimize the risk of future micro- and macrovascular complications. There are a number of available glucose-lowering agents from which to choose. This review focuses on the sulfonylureas, the first oral agents introduced for the management of Type 2 diabetes, which are effective, well-tolerated, and well-established drugs, Second-generation sulfonylureas are now widely used in the management of Type 2 diabetes. The most recent addition, glimepiride, can be used in combination with metformin, the thiazolidinediones, alpha-glucosidase inhibitors, and insulin. The unique properties of glimepiride may provide advantages over other currently available insulin secretagogues.

Sulfonylurea treatment of type 2 diabetes mellitus: focus on glimepiride

Sulfonylureas, which have evolved through two generations since their introduction nearly 50 years ago, remain the most frequently prescribed oral agents for treatment of patients with type 2 diabetes mellitus. Glyburide, glipizide, and glimepiride, the newest sulfonylureas, are as effective at lowering plasma glucose concentrations as first-generation agents but are more potent, better tolerated, and associated with a lower risk of adverse effects. Differences in their binding affinity to the beta-cell sulfonylurea receptor have been described, with preservation of cardioprotective responses to ischemia with glimepiride. Clinical studies have shown glimepiride to be safe and effective in reducing fasting and postprandial glucose levels, as well as glycosylated hemoglobin concentrations, with dosages of 1-8 mg/day. In comparative trials, glimepiride was as effective in lowering glucose levels as glyburide and glipizide, but glimepiride was associated with a reduced likelihood of hypoglycemia and a smaller increase in fasting insulin and C-peptide levels than glyburide, and a more rapid lowering of fasting plasma glucose levels than glipizide. Glimepiride also improves first-phase insulin secretion, which plays an important role in reducing postprandial hyperglycemia. Insulin secretagogues, specifically glimepiride, merit consideration as first-line therapy for patients with type 2 diabetes.

Effects of glimepiride on insulin secretion and sensitivity in patients with recently diagnosed type 2 diabetes mellitus

BACKGROUND

The exact mechanism of the efficacy of glimepiride in the achievement of glycemic control has not yet been clearly defined.

OBJECTIVE

This study was conducted to examine the influence of glimepiride on insulin secretion and sensitivity in patients with type 2 diabetes mellitus (DM) of recent onset.

METHODS

This 24-week, open-label, controlled trial was conducted at the Division of Endocrinology and Metabolism, Veterans Affairs Medical Center (Phoenix, Arizona). Study participants were aged 32 to 75 years and had recent-onset (established by a short duration of symptoms 6 weeks to 6 months prior to the study) type 2 DM, or were age-matched healthy volunteers (control group). In the diabetic patients, glimepiride tablets were administered orally, initially at 2 mg once daily in the morning, with the dosage increased by 1 mg every 2 weeks until fasting plasma glucose (FPG) decreased to 6.7 mmol/L; the dosage was then maintained for the remainder of the 24-week study period. Oral glucose tolerance tests (OGTTs) were conducted in the control group and before treatment and at 24 weeks after the achievement and maintenance of glycemic control (glycosylated hemoglobin <7.0%) in the diabetic group. For OGTT, plasma insulin and glucose levels were determined after the subjects fasted overnight and then at every 15 minutes for 2 hours after glucose challenge.

RESULTS

Fourteen diabetic men (mean [SEM] age, 50 [6] years; range, 32-75 years) and 10 male healthy controls (mean [SD] age, 48 [5] years; range, 30-68 years) were enrolled. In the DM group, FPG decreased significantly after treatment ( P<0.001); fasting plasma insulin was markedly elevated before treatment (P<0.001 vs controls) and decreased after treatment ( P<0.01) but did not normalize; first-phase insulin secretion was markedly inhibited before treatment ( P<0.001 vs controls) and normalized after treatment ( P<0.001) total insulin secretion significantly improved after treatment ( P<0.01) but did not normalize. Finally, the pretreatment insulin sensitivity index decreased significantly (P<0.01) after treatment and normalized in 6 of 14 patients (42.9%) with type 2 DM.

CONCLUSIONS

In this study, glimepiride achieved desirable glycemic control in patients with recent-onset type 2 DM through improvement in insulin secretion and sensitivity.

Prevention of weight gain in type 2 diabetes requiring insulin treatment

BACKGROUND

Patients with type 2 diabetes who are failing on oral agents will generally gain a large amount of body fat when switched to insulin treatment. This adverse effect may be related to chronic hyperinsulinism induced by long-acting insulin compounds.

AIM

To test the concept that regain of glycaemic control can be achieved without causing weight gain, using a regimen free of long-acting insulin.

METHODS

In a 3-month open-label pilot study including 25 patients with moderate overweight and secondary failure, we investigated whether nocturnal glycaemic control could be achieved with glimepiride administered at 20:00 hours. The starting dose was 1-2 mg, with subsequent titration up to a maximum of 6 mg. Rapid-acting insulin analogues were used three times daily to regain postprandial glucose control.

RESULTS

Glycaemic control at 3 months was established with glimepiride in a dose of 4.4 +/- 0.3 mg/day (mean +/- standard error of the mean), and a total daily insulin dose of 24.1 +/- 2.6 IU. Fasting glucose levels decreased from 12.7 +/- 0.6 mmol/l to 8.1 +/- 0.3 mmol/l (p < 0.001), and target levels were reached in 14 of 25 patients (56%). Mean HbA1c decreased from 10.5 +/- 0.4 to 7.7 +/- 0.2% (p < 0.001). Symptomatic nocturnal hypoglycaemia was not reported. Body weight did not change (85.7 +/- 3.6 kg vs. 85.7 +/- 3.3 kg, p = 0.99).

CONCLUSION

The data suggest that this new approach may be useful in about 50% of type 2 diabetes patients presenting with failure on maximal oral treatment.

Glimepiride Pharmacokinetics in Obese Versus Non-Obese Diabetic Patients

BACKGROUND:

Type 2 diabetes is a global concern, accounting for the vast majority of cases of diabetes. Type 2 diabetes is associated with insulin deficiency and insulin resistance and, increasingly, with patients who are overweight or obese. Glimepiride is a popular choice of oral antidiabetic agent for patients with Type 2 diabetes since it increases both insulin secretion and insulin sensitivity and, unlike some other oral agents, is associated with weight neutrality or even weight loss.

OBJECTIVE:

To assess the pharmacokinetic characteristics of glimepiride and its metabolites in normal-weight and morbidly obese patients with type 2 diabetes to determine whether the pharmacokinetics of glimepiride are altered by obesity.

METHODS:

Normal-weight (n = 14) and morbidly obese (n = 14) men and women (in a 1:1 ratio) with type 2 diabetes received a single oral dose of glimepiride 8 mg following an overnight fast. Serum concentrations of glimepiride and its metabolites, cyclohexyl hydroxymethyl derivative (MI) and carboxyl derivative (MII), and urinary concentrations of these metabolites were measured.

RESULTS:

There was no significant difference between the 2 patient groups for glimepiride in terms of mean peak concentration (Cmax) (p = 0.0807), time to reach Cmax (tmax) (p = 0.9916), AUC0–24 (p = 0.2609), AUC0–∞ (p = 0.1275), or terminal half-life (p = 0.3076). Mean tmax values and relative total clearances for the 2 groups were also equivalent. Some differences were noted with respect to the pharmacokinetics of metabolites between the groups. In particular, over a 24-hour period, the morbidly obese group excreted statistically significantly greater amounts of MI (p = 0.0430) and MII (p = 0.0051) compared with the normal-weight group. However, none of the differences was considered clinically significant since these metabolites do not have meaningful pharmacologic activity.

CONCLUSIONS:

Overall, the results presented here indicate that no intrinsic difference is observed in the oral clearance of glimepiride in obese patients compared with non-obese patients. Given that the dosage is titrated to achieve optimal fasting glucose levels, no special dose consideration is required for the use of glimepiride in the treatment of obese patients with type 2 diabetes.

Effects of glimepiride on HbA(1c) and body weight in Type 2 diabetes: results of a 1.5-year follow-up study

Sulphonylureas are effective and well tolerated in patients with Type 2 diabetes, but may be associated with weight gain, and lack of compliance due to multiple daily dosing. This open, uncontrolled surveillance study examined the efficacy and safety of glimepiride, a new sulphonylurea, administered once daily in patients with Type 2 diabetes. A total of 1,770 patients were enrolled in the study, and 284 patients were selected for follow-up. Patients received 0.5 to >4 mg glimepiride once daily for 1.5 years. HbA(1c) was reduced from 8.4% at baseline to 7.1% after 4 months and 6.9% after 1 and 1.5 years (median intra-individual change from baseline: -1.4, -1.5, and -1.7%, respectively; P<0.0001). Treatment with glimepiride also resulted in significant and stable weight loss relative to baseline, with the exception of patients with a body mass index of <25 kg/m(2). Mean body weight was reduced from 79.8 kg at baseline to 77.9 kg after 4 months, 77.2 kg after 1 year, and 76.9 kg after 1.5 years (mean intra-individual change from baseline: -1.9 kg, P<0.0001; -2.9 kg, P<0.05; -3.0 kg, P<0.005, respectively). Therefore, once daily glimepiride provides effective glycaemic control, and may have advantages over other sulphonylureas, because it exhibits weight neutralizing/reducing effects in patients with Type 2 diabetes.

Glimepiride in type 2 diabetes mellitus: a review of the worldwide therapeutic experience

BACKGROUND

Sulfonylureas (SUs) have been used for many years as first-line therapy for patients with type 2 diabetes mellitus whose blood glucose levels have not been effectively controlled by diet and exercise alone. Glimepiride is a once-daily SU that was introduced in 1995. Since then, a considerable body of evidence has been amassed regarding its use in type 2 diabetes.

OBJECTIVE

This review provides a comprehensive summary of available data on the pharmacology, pharmacokinetics, efficacy, and safety profile of glimepiride in the treatment of type 2 diabetes. It also examines the use of glimepiride to achieve and maintain good glycemic control in patients with type 2 diabetes in current clinical practice.

METHODS

Relevant articles were identified through a search of MEDLINE for English-language studies published from 1990 to 2002. The search terms used were glimepiride, sulfonylureas, and type 2 diabetes mellitus. The manufacturer of glimepiride provided additional information.

RESULTS

Glimepiride differs from other SUs in a number of respects. In clinical studies, glimepiride was generally associated with a lower risk of hypoglycemia and less weight gain than other SUs. Results of other studies suggest that glimepiride can be used in older patients and those with renal compromise. There is evidence that glimepiride preserves myocardial preconditioning, a protective mechanism that limits damage in the event of an ischemic event. Glimepiride can be used in combination with other oral antidiabetic agents or insulin to optimize glycemic control.

CONCLUSION

Based on the evidence to date, glimepiride is an effective and well-tolerated once-daily antidiabetic drug and provides an important treatment option for the management of type 2 diabetes.

Efficacy and safety profile of glimepiride in Mexican American Patients with type 2 diabetes mellitus: a randomized, placebo-controlled study

BACKGROUND

Mexican Americans, the fastest growing ethnic group in the United States, have a 2- to 3-fold higher prevalence of type 2 diabetes mellitus relative to the non-Hispanic white population. It is estimated that 10% of Mexican Americans >or=20 years of age have diabetes.

OBJECTIVE

The goal of this study was to evaluate the efficacy and safety of glimepiride, a long-acting sulfonylurea, as an adjunct to diet/exercise in Mexican Americans with type 2 diabetes mellitus.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled study. Mexican Americans with uncontrolled type 2 diabetes, defined as a fasting plasma glucose (FPG) level between 120 mg/dL and 225 mg/dL and glycated hemoglobin (HbA(1c)) values between 8.0% and 10.5%, after >or=3 months of diet/exercise were enrolled. Patients were randomized in a 2:1 ratio (using the lowest available treatment assignment number when eligibility was established) to receive 14 weeks of glimepiride or matching placebo once daily with continued diet/exercise. The starting glimepiride dose was 1 mg, with titration to 2 mg and 4 mg for FPG levels >120 mg/dL. The primary efficacy variable was change in HbA(1c) from baseline to study end point. Secondary efficacy variables were HbA(1c) response (rated as excellent, good, or marginal) and changes in FPG, fasting insulin, fibrinogen, and plasminogen activator inhibitor-1 (PAI-1) levels from baseline to study end point. The tolerability of glimepiride in this study population was determined by evaluating adverse events, hypoglycemic episodes, and physical examination as well as laboratory findings. All analyses were performed on an intent-to-treat basis. A per-protocol analysis also was conducted to support the primary efficacy analysis.

RESULTS

Seventy patients were randomized to treatment with glimepiride (n = 48) or placebo ((n = 22). The glimepiride and placebo groups were similar with respect to mean (SE) age (48.4 [11.7] and 50.7 [10.0] years, respectively) and sex (56.3% [27/48] and 50.0% [11/22] were male, respectively). However, the glimepiride group had a higher mean body weight (83.3 [17.0] vs 76.3 [18.5] kg) and a significantly higher mean fasting insulin level (23.8 [17.7] vs 17.8 [19.7] microU/mL; P = 0.031). The mean (SE) HbA(1c) values at study end point were 7.8% (0.2%) and 9.9% (0.7%) in patients receiving glimepiride and placebo, respectively. The adjusted mean difference in HbA(1c) reduction from baseline to end point was statistically significant in favor of glimepiride (-1.8% [0.4%]; P < 0.001). More pronounced HbA(1c) impairment at baseline was associated with greater glimepiride-placebo differences in HbA(1c) reduction. Glimepiride-treated patients also achieved a significantly greater improvement in FPG, with an adjusted mean (SE) treatment difference of -46.7 (16.7) mg/dL (P = 0.007). Glimepiride did not appear to affect fibrinogen and PAI-1 levels but was associated with significantly greater mean increases in fasting insulin (10.2 vs -2.1 microU/mL; P = 0.002) and body weight (2.3 vs 2.1 kg; P < 0.001) compared with placebo. Glimepiride was well tolerated, with an adverse-event profile similar to that of placebo.

CONCLUSIONS

These results indicate that once-daily glimepiride plus diet/exercise was effective in Mexican Americans with type 2 diabetes whose disease was inadequately controlled with diet/exercise alone. It appeared to be well tolerated in the population studied. More weight gain was seen with glimepiride compared with placebo. Given the high prevalence of type 2 diabetes among Mexican Americans, further clinical studies of glimepiride and other glucose-lowering therapies are needed in this ethnic subset.

Effect of metabolic inhibition on glimepiride block of native and cloned cardiac sarcolemmal K(ATP) channels

1. We have investigated the effects of the sulphonylurea, glimepiride, currently used to treat type 2 diabetes, on ATP-sensitive K(+) (K(ATP)) currents of rat cardiac myocytes and on their cloned constituents Kir6.2 and SUR2A expressed in HEK 293 cells. 2. Glimepiride blocked pinacidil-activated whole-cell K(ATP) currents of cardiac myocytes with an IC(50) of 6.8 nM, comparable to the potency of glibenclamide in these cells. Glimepiride blocked K(ATP) channels formed by co-expression of Kir6.2/SUR2A subunits in HEK 293 cells in outside-out excised patches with a similar IC(50) of 6.2 nM. 3. Glimepiride was much less effective at blocking K(ATP) currents activated by either metabolic inhibition (MI) with CN(-) and iodoacetate or by the K(ATP) channel opener diazoxide in the presence of inhibitors of F(0)/F(1)-ATPase (oligomycin) and creatine kinase (DNFB). Thus 10 microM glimepiride blocked pinacidil-activated currents by >99%, MI-activated currents by 70% and diazoxide-activated currents by 82%. 4. In inside-out patches from HEK 293 cells expressing the cloned K(ATP) channel subunits Kir6.2/SUR2A, increasing the concentration of ADP (1 - 100 microM), in the presence of 100 nM glimepiride, lead to significant increases in Kir6.2/SUR2A channel activity. However, over the range tested, ADP did not affect cloned K(ATP) channel activity in the presence of 100 nM glibenclamide. These results are consistent with the suggestion that ADP reduces glimepiride block of K(ATP) channels. 5. Our results show that glimepiride is a potent blocker of native cardiac K(ATP) channels activated by pinacidil and blocks cloned Kir6.2/SUR2A channels activated by ATP depletion with similar potency. However, glimepiride is much less effective when K(ATP) channels are activated by MI and this may reflect a reduction in glimepiride block by increased intracellular ADP.

The pathophysiologic basis of efficacy and clinical experience with the new oral antidiabetic agents

Type 2 diabetes results from the abnormal resistance of peripheral tissues to insulin and from the progressive insulin secretory failure of the pancreatic beta-cells. Treatment of type 2 diabetes has greatly improved due to the availability of new classes of oral antidiabetic drugs (OADs) and new insulin analogs. Three types of oral medications exert their antidiabetic action without directly stimulating insulin release: alpha-glucosidase inhibitors (e.g., acarbose) interfere with the digestion of dietary glucose precursors and the absorption of glucose; biguanides (e.g., metformin) inhibit hepatic gluconeogenesis, thereby lowering fasting blood glucose concentrations and increasing peripheral insulin sensitivity; and thiazolidinediones (e.g., rosiglitazone) improve the sensitivity of tissues to insulin-stimulated glucose disposal. In contrast, two classes of OADs stimulate insulin release from pancreatic beta-cells. Sulfonylureas (e.g., glyburide) have been used successfully for many years to treat type 2 diabetes, but their prolonged action may result in hypoglycemia. The third-generation sulfonylurea glimepiride is associated with a reduced risk of hypoglycemia and less weight gain than other sulfonylureas. Finally, the meglitinides (e.g., repaglinide) and D-phenylalanine derivatives (e.g., nateglinide) are powerful prandial insulin secretagogues. If the pancreatic beta-cells deteriorate to such an extent that insulin secretion is significantly impaired, treatment with additional exogenous insulin may be required.

Clinical review of glimepiride

This article reviews the pharmacological and clinical aspects of glimepiride, the latest second-generation sulfonylurea for treatment of Type 2 diabetes mellitus (DM). Glimepiride therapy ameliorates the relative insulin secretory deficit found in most patients with Type 2 DM. It is a direct insulin secretagogue; indirectly, it also increases insulin secretion in response to fuels such as glucose. Its action to augment insulin secretion requires binding to a high affinity sulfonylurea receptor, which results in closure of ATP-sensitive potassium channels in the beta-cells of the pancreas. The question has been raised whether insulin secretagogues by acting on vascular or myocardial potassium channels may prevent ischaemic preconditioning, a physiological adaptation that could affect the outcome of coronary heart disease, but there is evidence against this concern being applicable to glimepiride. Glimepiride's antihyperglycaemic efficacy is equal to other secretagogues. It has pharmacokinetic properties that make it less prone to cause hypoglycaemia in renal dysfunction than some other insulin secretagogues, particularly glyburide (also known as glibenclamide in Europe). Its convenient once daily dosing may enhance compliance for diabetic patients who often also require medications for other co-morbid conditions, such as hypertension, hyperlipidaemia and cardiac disease. Glimepiride is approved for monotherapy, for combination with metformin and with insulin. Clinically, its reduced risk of hypoglycaemia makes it preferable to some other insulin secretagogues when attempting to achieve recommended glycaemic control (haemoglobin A(1c) (HgbA(1c)) 7%). Using suppertime neutral protamine Hagedorn (NPH) and regular insulin with morning glimepiride in overweight diabetic patients achieves glycaemic goals more quickly than insulin alone and with lower insulin doses.

Analysis of glimepiride by using derivative UV spectrophotometric method

Glimepiride (Amaryl), which is a new oral antidiabetic drug in the sulfonylurea class, was analysed by using second order derivative UV spectrophotometry. The quantification of glimepiride in dimethylformamide was performed in the wavelength range of 245-290 nm at N = 6, ?lambda = 21. The second order derivative spectra was calculated using peak to peak (lambdaDMF = 263.3-268.2 nm), peak to zero (lambdaDMF = 268.2 nm) and tangent (lambdaDMF = 263.3-271.8 nm) method for calibration curves, the linearity range of 1.00-500.00 microg ml(-1) by using the second order derivative UV spectrophotometric method. The developed method was applied to directly and easily to the analysis of the pharmaceutical tablet preparations. R.S.D. were found to be 4.18% (Amaryl tablet; 1 mg) and 2.21% (Amaryl tablet; 2 mg). The method was completely validated and proven to be rugged. The limit of quantitation and the limit of detection were found as 1.00 and 0.4 microg ml(-1), respectively. This validated derivative UV spectrophotometric method is potentially useful for a routine laboratory because of its simplicity, rapidity, sensitivity, precision and accuracy.

The use of insulin secretagogues in the treatment of type 2 diabetes

Secretatogues are a class of agents that achieve their hypoglycemic effects through stimulating insulin release. They include the sulfonylureas, repaglinide, and the investigational agent glucagon-like peptide. The secretagogue agents have been studied extensively as monotherapy and in conjunction with other classes of oral agents, including alpha-glucosidase inhibitors, bijuanides, and thiazolidinediones, for the treatment of type 2 diabetes. This article reviews the pharmacodynamic and pharmacokinetic differences of the secretagogues, as well as the most recent clinical trials. Such information should be helpful when deciding which agent or agents will yield the best glycemic control for an individual patient.

Glimepiride: role of a new sulfonylurea in the treatment of type 2 diabetes mellitus

OBJECTIVE

To review the clinical pharmacology data regarding the sulfonylurea glimepiride, and to summarize the clinical trials of glimepiride efficacy and safety alone and in combination with insulin for the treatment of type 2 diabetes mellitus.

DATA SOURCES

A MEDLINE database search (English language, January 1985-April 1997) was performed to identify relevant published articles, including reviews and abstracts; the manufacturer (Hoechst Marion Roussel, Kansas City, MO) provided unpublished data.

STUDY SELECTION

Pharmacology information was taken from representative original research articles. Eight clinical studies were selected for analysis on the basis of large enrollment, appropriate study design, and publication of results.

DATA EXTRACTION

All clinical trials, published and unpublished, were reviewed.

DATA SYNTHESIS

Glimepiride is a sulfonylurea that is pharmacologically distinct from other sulfonylureas because of differences in receptor-binding properties and potentially selective effects on ATP-sensitive K+ channels. The pharmacokinetic and pharmacodynamic profile of glimepiride makes it suitable for once-daily dosing. The safety and efficacy of glimepiride have been confirmed in studies involving more than 5000 patients with type 2 diabetes. In one study, once-daily doses of 1-8 mg reduced fasting plasma glucose from baseline by 43-74 mg/dL more than did placebo (p < 0.001), and hemoglobin (Hb) A1C values decreased by 1.2-1.9% more than with placebo (p < 0.001). Two-thirds of patients achieved tight control (i.e., HbA1C < or = 7.2%). Glimepiride was as effective as second-generation sulfonylureas. The most common adverse events were dizziness and headache, but no single adverse event occurred in more than 2% of patients.

CONCLUSIONS

Glimepiride appears to be a useful option for patients with type 2 diabetes not controlled by diet and exercise and who want to achieve tight glucose control. Glimepiride can be used alone, in combination with other antihyperglycemic agents, or in patients with secondary sulfonylurea failure, as an adjunct to insulin therapy.

Glimepiride. A review of its use in the management of type 2 diabetes mellitus

Glimepiride is a sulphonylurea agent that stimulates insulin release from pancreatic beta-cells and may act via extrapancreatic mechanisms. It is administered once daily to patients with type 2 (non-insulin-dependent) diabetes mellitus in whom glycaemia is not controlled by diet and exercise alone, and may be combined with insulin in patients with secondary sulphonylurea failure. The greatest blood glucose lowering effects of glimepiride occur in the first 4 hours after the dose. Glimepiride has fewer and less severe effects on cardiovascular variables than glibenclamide (glyburide). Pharmacokinetics are mainly unaltered in elderly patients or those with renal or liver disease. Few drug interactions with glimepiride have been documented. In patients with type 2 diabetes, glimepiride has an effective dosage range of 0.5 to 8 mg/day, although there is little difference in efficacy between dosages of 4 and 8 mg/day. Glimepiride was similar in efficacy to glibenclamide and glipizide in 1-year studies. However, glimepiride appears to reduce blood glucose more rapidly than glipizide over the first few weeks of treatment. Glimepiride and gliclazide were compared in patients with good glycaemic control at baseline in a 14-week study that noted no differences between their effects. Glimepiride plus insulin was as effective as insulin plus placebo in helping patients with secondary sulphonylurea failure to reach a fasting blood glucose target level of < or = 7.8 mmol/L, although lower insulin dosages and more rapid effects on glycaemia were seen with glimepiride. Although glimepiride monotherapy was generally well tolerated, hypoglycaemia occurred in 10 to 20% of patients treated for < or = 1 year and > or = 50% of patients receiving concomitant insulin for 6 months. Pooled clinical trial data suggest that glimepiride may have a lower incidence of hypoglycaemia than glibenclamide, particularly in the first month of treatment. Dosage is usually started at 1 mg/day, titrated to glycaemic control at 1- to 2-week intervals to a usual dosage range of 1 to 4 mg/day (maximum 6 mg/day in the UK or 8 mg/day in the US).

CONCLUSIONS

Glimepiride is a conveniently administered alternative to other sulphonylureas in patients with type 2 diabetes mellitus not well controlled by diet alone. Its possible tolerability advantages and use in combination with other oral antidiabetic drugs require further study. Glimepiride is also reported to reduce exogenous insulin requirements in patients with secondary sulphonylurea failure when administered in combination with insulin.