The use of sulphonylureas in the elderly

Prevention of Chronic Kidney Disease and Its Complications in Older Adults

In an era marked by a global demographic shift towards an aging society, there is a heightened prevalence of chronic kidney disease (CKD) among older adults. The burden of CKD spans from kidney-related complications to impacting psychological well-being, giving rise to depressive symptoms and caregiver burnout. This article delves into CKD prevention strategies within the context of aging, contributing to the discourse by exploring its multifaceted aspects. The prevention of CKD in the older adults necessitates a comprehensive approach. Primary prevention is centered on the modification of risk factors, acknowledging the intricate interplay of various comorbidities. Secondary prevention focuses on early CKD identification. Tertiary prevention aims to address factors contributing to CKD progression and complications, emphasizing the importance of timely interventions. This comprehensive strategy aims to enhance the quality of life for individuals affected by CKD, decelerating the deterioration of functional status. By addressing CKD at multiple levels, this approach seeks to effectively and compassionately care for the aging population.

Application of Response Surface Methodology Using Face-centered Central Composite Design for Studying Long-Term Stability of Gliclazide-Loaded Multiparticulate Systems

The appropriate design of experiments (DoE) could support post-approval lean-stability approaches. A three-factor three-level face-centered design was constructed to evaluate the long-term stability of gliclazide (GLZ) alginate-gelatin beads. The formulation variables were GLZ%(X1), alginate:gelatin ratio(X2), and glutaraldehyde%(X3). The studied responses included GLZ release at predefined intervals in 0.1 N HCl (2 h) followed by phosphate buffer (pH 7.4). Model-dependent and independent approaches were utilized for comparison. DoE-model validation and reduction were implemented. All the studied formulations showed non-significant changes in the particle size (p > 0.05) and most of them showed similar release profiles before and after storage. The directions of the relationships between the factors' main effects and the responses (Y1:Q0.5h, Y2:Q2h, and Y3:Q4h) remained unchanged after storage. The optimal factor settings based on the proposed optimization criteria were defined. The optimized formulations (OP-1 and OP-2) showed non-significant changes in the particle size after storage. The release profiles and kinetics of OP-1 and OP-2 remained unchanged after storage. No chemical change was indicated (FT-IR). DSC-thermograms of OP-1 indicated GLZ conversion to a more stable polymorph after storage. While OP-2 showed a change in GLZ crystallinity. The stored and fresh beads' surfaces after GLZ release were almost similar. DoE could be utilized to evaluate, optimize, and predict the effects of different formulation variables on the long-term stability of GLZ alginate-gelatin beads.

Asian Best Practices for Care of Diabetes in Elderly (ABCDE)

The elderly population with diabetes is diverse with the majority experiencing a decline in physical and mental capabilities, impacting the entire diabetes management process. Therefore, a need for geriatric-specific guidelines, especially for the Asian population, was identified and subsequently developed by an expert panel across government and private institutions from several Asian countries. The panel considered clinical evidence (landmark trials, position papers, expert opinions), recommendations from several important societies along with their decades of clinical experience and expertise, while meticulously devising thorough geriatric-specific tailored management strategies. The creation of the ABCDE best practices document underscores and explores the gaps and challenges and determines optimal methods for diabetes management of the elderly population in the Asian region.

Gliclazide: Biopharmaceutics Characteristics to Discuss the Biowaiver of Immediate and Extended Release Tablets

The lists of essential medicines of the World Health Organization (WHO) and Brazil include gliclazide as an alternative to the oral antidiabetic drug of first choice, metformin, in the treatment of type 2 diabetes mellitus because of its pharmacokinetic profile and few side effects. Thus, it is also considered by WHO and the International Pharmaceutical Federation (FIP) as a drug candidate to biowaiver, which is the evaluation of how favorable the biopharmaceutics characteristics are in order to obtain waiver from the relative bioavailability/bioequivalence (RB/BE) studies to register new medicines. This paper presents a review about the solubility, permeability and dissolution of gliclazide. A critical analysis of the information allowed to identify gliclazide as a Biopharmaceutics Classification System (BCS) Class II drug. Therefore, new drugs in immediate release dosage forms will not be eligible for biowaiver. Regarding the extended release dosage forms, besides the limited solubility, no information on the comparative dissolution profile was found, which would be necessary to analyze a possible biowaiver for a smaller dosage. It can be concluded that the registration of new medicines containing gliclazide must undergo RB/BE studies, since there is not enough evidence to recommend the replacement and waiver of such studies for immediate and extended release formulations.

Sixty Years of Drug Discovery for Type 2 Diabetes: Where Are We Now?

Today, excluding insulin, there are eight classes of anti-diabetic medicines that have been added to the pharmacy since the introduction of metformin in the mid-1950s; the sulfonylureas, biguanides, thiazolidinediones, α-glucosidase inhibitors, meglitinides, incretins, and sodium glucose transport 2 inhibitors. Does the fact that metformin is still first-line treatment suggest that our drug discovery efforts over the past 60 years have not been good enough? Or does it suggest that diabetes is such a complex disorder that no single treatment, other than gastric bypass surgery, can affect true normalization of not only blood sugar but also the underlying pathologies? Our understanding of the disease has most definitely improved which may bring hope for the future in terms of science, but for it to be beneficial, this science has to be translated into better drug treatments for the disease. In this review, I have examined the eight classes of anti-diabetes drugs from a drug discovery perspective.

Optimization of gliclazide loaded alginate-gelatin beads employing central composite design

Objective: The aim of this study was to optimize the formulation of alginate-gelatin (AL-GL) beads containing gliclazide (GLZ) employing design of experiments (DOE).Significance: DOE enabled identification of the interaction between the studied factors, deep understanding of GLZ release pattern and acceleration of the optimization process.Methods: A three-factor, three-level face centered design was employed. The effects of GLZ content (GLZ%, X₁), polymer ratio (AL:GL ratio, X₂), crosslinker concentration (glutaraldehyde, GA%, X₃), and their interaction on incorporation efficiency (IE) and release rate were studied. The optimized formulation was prepared using numerical optimization and evaluated by DSC, FT-IR, SEM and release rate studies.Results: Increasing GA% (X₃) decreased IE (Y₁) with the highest magnitude of effect among the studied factors. On the other hand, increasing alginate content in AL:GL ratio (X₂) increased IE (Y₁). The amount of GLZ released Q_0.5h, Q_2h(pH 1.2) and Q_4h(pH 7.4) decreased by increasing GLZ% (X₁) and AL:GL ratio (X₂). Both drug content and AL:GL ratio appeared to affect water penetration into the gel matrix and drug release. Generally, there was a direct relationship between GA% (X₃) and GLZ release in pH 1.2 (Q_0.5h and Q_2h). However, in pH 7.4 (Q_4h), increasing GA% decreased GLZ release. In addition, increasing GA% caused deviation from zero-order release model. The actual responses of the optimized formulation were in close agreement with the predicted ones.Conclusion: The selected factors and their levels studied in the optimization design were useful for tailoring the anticipated formulation characteristics and GLZ release pattern.

Characterization of tolazamide binding with glycated and normal human serum albumin by using high-performance affinity chromatography

Sulfonylurea drugs are antidiabetic drugs that are utilized in the treatment of type II diabetes and often have significant binding with human serum albumin (HSA). Immobilized samples of normal or glycated HSA in affinity microcolumns were used to investigate interactions of these proteins with the sulfonylurea drug tolazamide. HPLC and frontal analysis were used to first examine the overall binding of this drug with these samples of HSA. It was found that tolazamide had two general classes of binding sites (i.e., high and low affinity) for normal and glycated HSA. The higher affinity sites had binding constants of around 4.3-6.0 × 10⁴ M^-1 for these interactions at pH 7.4 and 37 °C, while the lower affinity sites had binding strengths of 4.9-9.1 × 10³ M^-1. Zonal competition studies between tolazamide and probes for Sudlow sites I and II on HSA were also performed and used to provide site-specific affinities for tolazamide at these sites. A decrease of 22% in affinity was observed for tolazamide at Sudlow site I and an increase up to 58% was seen at Sudlow site II when comparing glycated HSA with normal HSA. These observed changes were compared to those of other first-generation sulfonylurea drugs, providing information on how glycation can alter the total and local binding strength of tolazamide and related compounds with HSA under levels of glycation seen in patients with diabetes.

Chromatographic studies of chlorpropamide interactions with normal and glycated human serum albumin based on affinity microcolumns

Sulfonylurea drugs have significant binding to proteins in blood, with most of this binding believed to occur with human serum albumin (HSA). High performance affinity chromatography and affinity microcolumns containing immobilized HSA were used to investigate binding by the sulfonylurea drug chlorpropamide to normal HSA and glycated HSA, which is a modified form of HSA that has an increased serum concentration in diabetes. Experiments employing frontal analysis indicated that the binding by chlorpropamide gave a good fit to a two-site model for both normal HSA and glycated HSA samples that were representative of controlled or advanced diabetes. These interactions involved a set of moderate-to-high affinity sites and a set of lower affinity sites, with binding constants in the range of 6.2-9.9 × 10⁴ M^-1 and 0.18-0.57 × 10⁴ M^-1, respectively, at pH 7.4 and 37 °C. Competition studies utilizing a zonal elution format demonstrated that chlorpropamide could interact at both Sudlow sites I and II of HSA, with affinities in the range expected for the moderate-to-high affinity sites of this drug. The affinity of chlorpropamide at Sudlow site I had a small increase of up to 1.2-fold when comparing the normal HSA and glycated HSA samples. Chlorpropamide gave a larger 1.4- to over 1.5-fold increase at Sudlow site II when the affinity of this drug was compared between normal HSA and the same samples of glycated HSA. These results were compared to those obtained previously with other sulfonylurea drugs to help determine how glycation can change the overall and site-selective binding strength of these drugs with HSA at levels of protein modification that are seen in patients with diabetes.

Gliclazide

Gliclazide is a second-generation oral hypoglycemic drug used for the treatment of noninsulin-dependent diabetes mellitus. It belongs to the sulfonylurea class that stimulates insulin secretion from pancreatic β-cells by inhibiting ATP-dependent potassium channels. Gliclazide also possesses unique antioxidant properties and other beneficial hemobiological effects. This profile represents a comprehensive description of the physical properties, chemical synthesis, spectroscopic characterization (FTIR, ¹H NMR, ¹³C NMR, UV, and single-crystal X-ray), methods of analysis, pharmacological actions, and pharmacokinetic and pharmacodynamic properties of the title drug.

Sulfonylurea monotherapy and emergency room utilization among elderly patients with type 2 diabetes

AIM

In elderly Americans with type 2 diabetes, use of insulin and oral antidiabetic drugs (OADs) accounts for almost one-fourth of drug adverse event-related hospitalizations. It is not clear, however, if sulfonylureas (SUs), frequently prescribed OADs known to cause hypoglycemia, increase the risk of emergency room (ER) visits compared to other OADs. The aim of this study was to compare the emergency room utilization between US elderly patients with diabetes on SU monotherapy vs. other non-SU monotherapies.

METHODS

This retrospective cohort study was conducted using MarketScan(®) database (2009-10) and aimed to evaluate the association between use of SU and ER visits. The analysis included 28,533 patients (aged ≥65 years) receiving SU monotherapy at baseline and 1:1 propensity score (PS)-matched group receiving monotherapy with other OADs. ER utilization was determined during a 1-year follow-up period.

RESULTS

The SU and non-SU groups were overall well balanced after PS matching. The mean (SD) number of ER visits during the follow-up was 0.56 among users of SU users compared to 0.49 (P<0.0001) among non-users. In multivariable analysis, the adjusted odds ratios for ≥2 ER visits were 1.21 (95% CI=1.13-1.30) comparing SU users to non-users and 1.31 (95% CI=1.21-1.41) for SU vs. metformin users.

CONCLUSION

Elderly patients with type 2 diabetes on SU monotherapy were more likely to use ER than those on other monotherapies. Further studies are needed to confirm our findings and evaluate other factors associated with ER visits.

Options for combination therapy in type 2 diabetes: comparison of the ADA/EASD position statement and AACE/ACE algorithm

Treating patients with diabetes is one of the most challenging and important activities a physician (primary care physician or specialist) can undertake. A key to successful therapy for type 2 diabetes is the insight that this condition is progressive and that the need for additional agents over time is normative. The ability to individualize therapy by patient and medication characteristics comes from experience and knowledge of pertinent clinical studies. However, guidelines from expert bodies such as the American Diabetes Association/European Association for the Study of Diabetes and American Association of Clinical Endocrinologists/American College of Endocrinology can help clinicians of all levels of expertise to approach therapy choices more rationally. There is unity across these guidelines about the role and benefits of metformin as first-line pharmacological treatment, probability of good efficacy, low risk of hypoglycemia, modest weight loss, and overall long-term data. Unfortunately, this unity does not extend to recommendations for subsequent pharmacological agents and their use in combination to intensify treatment when insulin is not (yet) appropriate. Across both statements, some drug classes seem more prominent, and looking at their benefit-risk profile, it is clear why this is the case. The most profound recent change in diabetes therapy has been the introduction of incretin therapies. Incretin therapies minimize 2 important adverse effects seen with many other therapies: hypoglycemia and weight gain. These agents have increased the range of options available for early intensification of treatment of type 2 diabetes. In combination with more established therapies, there are more opportunities than ever to accommodate patient preferences while improving glycemic control and harnessing extraglycemic benefits of a second (or third) agent.

Pharmacologic management of the older patient with type 2 diabetes mellitus

BACKGROUND

Pharmacologic options for the treatment of elderly patients with type 2 diabetes mellitus (T2DM) are the same as in younger adults; however, treatment considerations differ in the elderly due to changes in renal and hepatic function, life expectancy, and various other clinical and practical considerations.

OBJECTIVE

This article discusses geriatric considerations in the pharmacologic management of T2DM and reviews the potential clinical advantages and disadvantages of pharmacologic agents currently available for the treatment of T2DM, including oral and injectable medications.

METHODS

A search of MEDLINE was conducted for articles published in English between January 1966 and September 2009 using the terms type 2 diabetes mellitus, elderly, geriatric, treatment, insulin, metformin, sulfonylurea, thiazolidinedione, alpha-glucosidase inhibitor, meglitinide, DPP-4 inhibitor, colesevelam, exenatide, and pramlintide. Meta-analyses, randomized controlled trials of pharmacologic treatment, and evidence-based reviews and/or expert opinions regarding the treatment of T2DM in the elderly were selected for review.

RESULTS

In overweight patients, metformin has been associated with reductions in risk for all-cause mortality and stroke compared with insulin and sulfonylureas. Older patients who are frail, anorexic, or underweight and those with congestive heart failure (CHF), renal or hepatic insufficiency, or dehydration may not be appropriate candidates for metformin therapy. The substantial risk of hypoglycemia with insulin secretagogues is increased by 36% in the elderly compared with younger adults; however, this risk is counterbalanced by the extensive clinical experience with these agents in the geriatric population. Thiazolidinediones should generally be avoided in patients with CHF and are absolutely contraindicated in patients with class II-IV heart failure. They have been associated with peripheral edema, as well as with decreases in bone mineral density in women. There is limited information on the use of dipeptidyl peptidase-4 inhibitors in the elderly, although dose adjustment is required in patients with renal compromise. In practice, substantial gastrointestinal adverse effects limit the use of alpha-glucosidase inhibitors in older patients. Colesevelam is associated with numerous drug interactions and can cause new or worsening constipation. There are limited data on the use of exenatide in the elderly. It may be beneficial in older patients with limited mobility who could benefit from weight loss, whereas it may not be a good option for frail, underweight adults. Use of exenatide is not recommended in patients with a creatinine clearance <30 mL/min. Given the increased monitoring required to avoid hypoglycemic events with pramlintide, this agent should be used with caution in older adults, particularly the frail elderly. Most patients with T2DM eventually require insulin; however, due to the risk of hypoglycemia and related morbidity, careful use of insulin is warranted in the geriatric population.

CONCLUSIONS

Overall, there is a scarcity of data regarding the use of pharmacologic agents in older adults with T2DM, and clinical guidance is largely based on data obtained from younger populations. The selection of appropriate drug regimens for these patients remains challenging.

Future perspectives for insulinotropic agents in the treatment of type 2 diabetes-DPP-4 inhibitors and sulphonylureas

The introduction of dipeptidyl-peptidase IV inhibitors (DPP-4 inhibitors) brought a novel class of insulinotropic agents into the treatment options for type 2 diabetes. This paper compares the actions, clinical efficacy and safety of sulphonylureas with those of the DPP-4 inhibitors. First, the mode of action of both classes of antidiabetic agents is described. Then clinical studies for both substances in monotherapy and combination therapies are compared concerning their effects on glycaemic parameters and long-term duration of action. Hypoglycaemia incidence and other adverse effects are compared and data on cardiovascular parameters and endpoints are summarized. The effects of sulphonylureas and DPP-4 inhibitors on beta-cell function and beta-cell mass are highlighted. The present and future indications for both sulphonylureas and DPP-4 inhibitors are discussed.

Comorbidity in the elderly with diabetes: Identification of areas of potential treatment conflicts

AIMS

To investigate the prevalence of comorbid conditions in the elderly with diabetes and the prescribing of potentially inappropriate medicines or treatment conflicts.

METHODS

A cross-sectional study of diabetics aged >or=65 years, using prescription dispensing data from the Australian Department of Veterans' Affairs. Comorbidities were determined using the comorbidity index Rx-Risk-V. Potentially inappropriate prescribing or treatment conflicts specific for the elderly were determined from guidelines or reference compendia, in addition to the 2003 updated Beers criteria.

RESULTS

Of 18,968 diabetics, the median number of comorbidities was 5 (IQR 3-8). Diabetes and associated cardiovascular medicines accounted for 41.9% of all medicine use. Associated cardiovascular diseases were highly prevalent comorbidities. 46% had gastro-oesophageal reflux disease, 25% depression, 20% chronic airways disease or chronic pain and 15% also had heart failure or inflammation-pain. At least 16% were dispensed a medicine associated with adverse effects in patients with diabetes and 22.7% were dispensed at least one potentially inappropriate medicine.

CONCLUSION

Significant comorbid conditions in elderly diabetic patients with potential for inappropriate prescribing or treatment conflicts include arthritis, heart failure, chronic airways diseases and diseases treatable with systemic corticosteroids. Appropriate management of comorbidity should be included in guidelines for the elderly with diabetes.

A composite screening tool for medication reviews of outpatients: general issues with specific examples

Regular performance of medication reviews is prominent among methods that have been advocated to reduce the extent and seriousness of drug-related problems, such as adverse drug reactions, drug-disease interactions, drug-drug interactions, drug ineffectiveness and cost ineffectiveness. Several screening tools have been developed to guide practising healthcare professionals and researchers in reviewing the medication patterns of elderly patients; however, each of these tools has its own limitations. This review discusses a wide range of general prescription-, treatment- and patient-related issues that should be taken into account when reviewing medication patterns by implicit screening. These include generic and therapeutic substitution; potentially superfluous or inappropriate medications; potentially inappropriate dosages or duration of treatment; drug-disease and drug-drug interactions; under-treatment; making use of laboratory test results; patient adherence, experiences and habits; appropriate dosage forms and packaging. A broad selection of specific examples and references that can be used as a basis for explicit screening of medication patterns in outpatients is also offered.

Use of antidiabetic drugs in elderly patients

The objective of this review of the literature is to analyze the results of studies including diabetic patients aged 70 years and older. Although the risk of treatment is greater in this population because of co-morbid conditions and altered renal function, information on the pharmacokinetics and pharmacodynamics of antidiabetic drugs remains limited. Long-term experience with sulfonylureas is sufficient to establish certain general rules of use; but for biguanides and alpha-glucosidase inhibitors, problems of tolerance limit use; further data are needed on glinides and glitazones. Use of insulin or insulin analogs is frequent and prescription should be adapted to achieve an acceptable balance between the risk of hypoglycaemia and therapeutic goals.

Bench-to-bedside review: Antidotal treatment of sulfonylurea-induced hypoglycaemia with octreotide

The major potential adverse effect of use of sulfonylurea agents (SUAs) is a hyperinsulinaemic state that causes hypoglycaemia. It may be observed during chronic therapeutic dosing, even with very low doses of a SUA, and especially in older patients. It may also result from accidental or intentional poisoning in both diabetic and nondiabetic patients. The traditional approach to SUA-induced hypoglycaemia includes administration of glucose, and glucagon or diazoxide in those who remain hypoglycaemic despite repeated or continuous glucose supplementation. However, these antidotal approaches are associated with several shortcomings, including further exacerbation of insulin release by glucose and glucagon, leading only to a temporary beneficial effect and later relapse into hypoglycaemia, as well as the adverse effects of both glucagon and diazoxide. Octreotide inhibits the secretion of several neuropeptides, including insulin, and has successfully been used to control life-threatening hypoglycaemia caused by insulinoma or persistent hyperinsulinaemic hypoglycaemia of infancy. Therefore, this agent should in theory also be useful to decrease glucose requirements and the number of hypoglycaemic episodes in patients with SUA-induced hypoglycaemia. This has apparently been confirmed by experimental data, one retrospective study based on chart review, and several anecdotal case reports. There is thus a need for further prospective studies, which should be adequately powered, randomized and controlled, to confirm the probable beneficial effect of octreotide in this setting.

Repeat prescribing: scale, problems and quality management in ambulatory care patients

The reported scale of repeat prescriptions ranges from 29% to 75% of all items prescribed, depending on the definition of repeat prescribing and other variables. It is likely that a substantial part of repeat prescribing by general practitioners (GPs) occurs without direct doctor-patient contact. While this reduces the workload for the GP and is convenient for the patient, it does not provide the adequate control that is needed to ensure that every repeat prescription is still appropriate, effective and well tolerated, and that it is still being viewed upon and taken by the patient as intended. Infrequent therapy reviews may lead to failure to prevent, identify and solve drug-related problems and drug wastage, and may, thereby, have a negative impact on the effectiveness, safety or cost of the medications prescribed. Studies evaluating the repeat prescribing process have shown that GPs and medical practices vary widely in their degree of administrative and clinical control of repeat prescriptions. Contrary to the opinion that GPs cannot change prescribing behaviour when the prescription is initiated by a medical specialist, GPs have their own responsibility for controlling the repeats of such prescriptions. Intervention studies suggest that a medication review by a pharmacist can help to reduce drug-related problems with repeat prescriptions, and the effectiveness of the intervention may be increased by combining the medication review with a consultation of the patient's medical records and a patient interview. In several studies, such an intervention was relatively inexpensive and, therefore, feasible. However, these conclusions should be viewed with appropriate caution because a number of caveats pertain. There is still no evidence that these types of intervention improve health-related quality of life or reduce healthcare cost, and so far only a few trials have produced any evidence of clinical improvement. As implicit and explicit screening criteria have their own benefits and limitations, a combined application may offer a more thorough assessment but may also be more complex and time consuming. Further studies on the development and evaluation of repeat prescription management models are needed, preferably focussing on improving clinical, humanistic and economic outcomes. New studies should investigate the effects of: different types of interventions; different organisational models; different target populations; and selecting and training different types of healthcare professionals. Future studies should also assess whether results are sustained, the optimal time interval between reviews of repeat prescriptions, and the possibilities offered by new computerised support technologies.

The role of sulphonylureas in the management of type 2 diabetes mellitus

The sulphonylureas act by triggering insulin release from the pancreatic beta cell. A specific site on the adenosine triphosphate (ATP)-sensitive potassium channels is occupied by sulphonylureas leading to closure of the potassium channels and subsequent opening of calcium channels. This results in exocytosis of insulin. The meglitinides are not sulphonylureas but also occupy the sulphonylurea receptor unit coupled to the ATP-sensitive potassium channel. Glibenclamide (glyburide), gliclazide, glipizide and glimepiride are the primary sulphonylureas in current clinical use for type 2 diabetes mellitus. Glibenclamide has a higher frequency of hypoglycaemia than the other agents. With long-term use, there is a progressive decrease in the effectiveness of sulphonylureas. This loss of effect is the result of a reduction in insulin-producing capacity by the pancreatic beta cell and is also seen with other antihyperglycaemic agents. The major adverse effect of sulphonylureas is hypoglycaemia. There is a theoretical concern that sulphonylureas may affect cardiac potassium channels resulting in a diminished response to ischaemia. There are now many choices for initial therapy of type 2 diabetes in addition to sulphonylureas. Metformin and thiazolidinediones affect insulin sensitivity by independent mechanisms. Disaccharidase inhibitors reduce rapid carbohydrate absorption. No single agent appears capable of achieving target glucose levels in the majority of patients with type 2 diabetes. Combinations of agents are successful in lowering glycosylated haemoglobin levels more than with a single agent. Sulphonylureas are particularly beneficial when combined with agents such as metformin that decrease insulin resistance. Sulphonylureas can also be given with a basal insulin injection to provide enhanced endogenous insulin secretion after meals. Sulphonylureas will continue to be used both primarily and as part of combined therapy for most patients with type 2 diabetes.

Antidiabetic drug therapy of African-American and white community-dwelling elderly over a 10-year period

OBJECTIVES

To determine the prevalence and predictors of antidiabetic medication use over a 10-year period in a general population of African-American and white community-dwelling elderly.

DESIGN

Survey.

SETTING

Five adjacent counties (one urban and four rural) in the Piedmont area of North Carolina.

PARTICIPANTS

Those aged 65 and older present at the baseline (n=4,136), second (n=3,234), third (n=2,508), and fourth (n=1,633) in-person waves of the Duke Established Populations for Epidemiologic Studies of the Elderly.

MEASUREMENTS

The use of six discrete categories of antidiabetic medications (insulin, first-generation oral sulfonylureas, second-generation oral sulfonylureas, metformin, oral combination therapy, and insulin combination therapy) was determined. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between antidiabetic medication use and race and other sociodemographic, health-status, and access-to-healthcare factors at baseline and 10 years later.

RESULTS

Antidiabetic medications were taken by 21.4% of the population at baseline; this increased to 28.1% at the 10-year follow-up (P<.001). Insulin was the most commonly used drug at baseline (7.9%). The use of second-generation sulfonylureas increased, and use of first-generation sulfonylureas decreased over the 10-year time period. Combination antidiabetic therapy and metformin use was infrequent throughout the study. Multivariate analyses revealed that, at baseline, African Americans were nearly twice as likely (adjusted odds ratio (AOR)=1.93, 95% confidence interval (CI)=1.46-2.54) to receive any antidiabetic medication as their white counterparts. Other significant (P<.05) factors were hypertension (AOR=1.38, 95% CI=1.03-1.84), stroke (AOR=1.98, 95% CI=1.43-2.73), one or more mobility difficulties (AOR=1.29, 95% CI=1.01-1.66), continuity of care (AOR=1.74, 95% CI=1.20-2.54), and multiple doctor visits (1-4 visits, AOR=1.69, 95% CI=1.08-2.65; >/=5 visits, AOR=3.15, 95% CI=1.95-5.07). Being underweight (AOR=0.45, 95% CI=0.30-0.67) and being cognitively impaired (AOR=0.60, 95% CI=0.41-0.87) were factors significantly (P<.05) associated with a decreased risk of antidiabetic medication use. At the 10-year follow-up, similar trends were seen associating these sociodemographic, health-status, and access-to-healthcare factors with antidiabetic medication use.

CONCLUSION

Antidiabetic medication use is common and increases over time for community-dwelling elderly. Race is significantly associated with antidiabetic medication use, even after controlling for other sociodemographic, health-status, and access-to-healthcare variables.

Treatment of patients over 64 years of age with type 2 diabetes: experience from nateglinide pooled database retrospective analysis

OBJECTIVE

To evaluate the impact of renal impairment (RI) (estimated creatinine clearance [Cl(cr)] <60 ml/min per 1.73 m(2)) and low baseline HbA(1c) (<7.5%) on comorbidity in patients with type 2 diabetes, and to assess the efficacy and safety of nateglinide monotherapy in these patients and in subgroups of patients over age 64 years (elderly) and elderly with RI.

RESEARCH DESIGN AND METHODS

Retrospective subgroup analyses were performed on pooled data from all completed nateglinide studies (12 randomized, double blind trials and 1 open trial) in patients with type 2 diabetes. A total of 3,702 patients with > or =1 postbaseline safety evaluation received monotherapy with nateglinide (n = 2,204), metformin (n = 436), glyburide (n = 293), or placebo (n = 769). Efficacy (HbA(1c)) was evaluated in pooled data from four studies with similar design using 120 mg nateglinide (n = 544) versus placebo (n = 521). Evaluations were performed in the overall population and subgroups of patients over age 64 years. Specific considerations were given to RI, comorbidity, and baseline HbA(1c).

RESULTS

Patients over age 64 years (n = 1,170) represented 31.6% of the study population. Undiagnosed RI was common in the elderly with 83.4% of all patients being in this subgroup. Patients over 64 years with RI had a higher prevalence of cardio- and microvascular comorbidity compared with the overall population and all patients over age 64 years. Statistically significant HbA(1c) reductions versus placebo were observed with nateglinide in patients over age 64 years and elderly with RI patients at study end point (-0.9% and -1.1% in each subgroup, P < 0.01). Nateglinide was well tolerated with a low incidence of hypoglycemia in all subgroups, including those with RI and low baseline HbA(1c).

CONCLUSIONS

RI and comorbidity are common in patients over age 64 years with type 2 diabetes. Nateglinide was effective and well tolerated in all treated patients. In subgroups in which metformin and long-acting sulfonylureas must be used with caution, nateglinide had a low risk of adverse events and hypoglycemia.

Lower incidence of severe hypoglycaemia in patients with type 2 diabetes treated with glimepiride versus glibenclamide

BACKGROUND

Severe hypoglycaemia is a potentially life-threatening condition. The aim of the present study was to compare the frequency of severe hypoglycaemia in patients with type 2 diabetes treated with glimepiride versus glibenclamide.

METHODS

This prospective, population-based, 4-year study examined the incidence of severe hypoglycaemia in a region of Germany with 200 000 inhabitants. The blood glucose of all 30 768 patients who attended the emergency department of the region's central hospital was determined to detect severe hypoglycaemia, which was defined by the requirement for intravenous glucose or glucagon injection and blood glucose value of <2.8 mmol/l. Additionally, 6631/7804 patients (85%) attended to by the emergency medical services received a blood glucose test at the emergency site. The regional prescribing frequency of both sulphonylureas was determined by an independent external institute.

RESULTS

Despite glimepiride being prescribed more frequently than glibenclamide (6976 vs 6789 person-years), glimepiride induced fewer episodes of hypoglycaemia (6 vs 38 episodes); one episode occurred with a combination of the two preparations. The incidence of severe hypoglycaemia was 0.86/1000 person-years for glimepiride and 5.6/1000 person-years for glibenclamide. The characteristics of the 45 patients who presented with sulphonylurea-associated hypoglycaemia were as follows: mean age 79 years (95% CI 75.2; 82.6); glycosylated haemoglobin 5.4% (95% CI 5.1; 5.7); impaired renal function in 62%.

CONCLUSIONS

In people with type 2 diabetes, glimepiride was associated with fewer episodes of severe hypoglycaemia than glibenclamide in routine clinical use. However, severe hypoglycaemia did occur with glimepiride and may be minimised if treatment targets are determined on an individual basis.

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.

Gliclazide modified release: its place in the therapeutic armamentarium

The constraints of intensive multifactorial management of type 2 diabetes dictate a need for effective, well-tolerated agents with simple administration regimens. Sulfonylureas remain the most frequently used agents, and represent a rational approach when consideration is given to the pathophysiology of this common condition. Trials of gliclazide modified release in varied populations have yielded very acceptable clinical results that support its first-line use in type 2 diabetes, including obese, elderly, and mild-to-moderate renal insufficient patients. The simplicity of its dose regimen and its efficacy and tolerance profile may significantly contribute to improving compliance.