Gliclazide and bedtime insulin are more efficient than insulin alone for type 2 diabetic patients with sulfonylurea secondary failure

Current Position of Gliclazide and Sulfonylureas in the Contemporary Treatment Paradigm for Type 2 Diabetes: A Scoping Review

The increasing burden of type 2 diabetes (T2D), in relation to alarming rise in the prevalence; challenges in the diagnosis, prevention, and treatment; as well as the substantial impact of disease on longevity and quality of life, is a major concern in healthcare worldwide. Sulfonylureas (SUs) have been a cornerstone of T2D pharmacotherapy for over 60 years as oral antidiabetic drugs (OADs), while the newer generation SUs, such as gliclazide modified release (MR), are known to be associated with low risk of hypoglycemia in addition to the cardiovascular neutrality. This scoping review aimed to specifically address the current position of gliclazide MR among other SUs in the contemporary treatment paradigm for T2D and to provide a practical guidance document to assist clinicians in using gliclazide MR in real-life clinical practice. The main topics addressed in this paper include the role of early and sustained glycemic control and use of SUs in T2D management, the properties of gliclazide MR in relation to its effectiveness and safety, the use of gliclazide therapy in special populations, and the place of SUs as a class and gliclazide MR specifically in the current T2D treatment algorithm.

Insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control

BACKGROUND

It is unclear whether people with type 2 diabetes mellitus on insulin monotherapy who do not achieve adequate glycaemic control should continue insulin as monotherapy or can benefit from adding oral glucose-lowering agents to the insulin therapy.

OBJECTIVES

To assess the effects of insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin monotherapy for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and reference lists of articles. The date of the last search was November 2015 for all databases.

SELECTION CRITERIA

Randomised controlled clinical trials of at least two months' duration comparing insulin monotherapy with combinations of insulin with one or more oral glucose-lowering agent in people with type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, extracted data and evaluated overall quality of the evidence using GRADE. We summarised data statistically if they were available, sufficiently similar and of sufficient quality. We performed statistical analyses according to the statistical guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included 37 trials with 40 treatment comparisons involving 3227 participants. The duration of the interventions ranged from 2 to 12 months for parallel trials and two to four months for cross-over trials.The majority of trials had an unclear risk of bias in several risk of bias domains. Fourteen trials showed a high risk of bias, mainly for performance and detection bias. Insulin monotherapy, including once-daily long-acting, once-daily intermediate-acting, twice-daily premixed insulin, and basal-bolus regimens (multiple injections), was compared to insulin in combination with sulphonylureas (17 comparisons: glibenclamide = 11, glipizide = 2, tolazamide = 2, gliclazide = 1, glimepiride = 1), metformin (11 comparisons), pioglitazone (four comparisons), alpha-glucosidase inhibitors (four comparisons: acarbose = 3, miglitol = 1), dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) (three comparisons: vildagliptin = 1, sitagliptin = 1, saxagliptin = 1) and the combination of metformin and glimepiride (one comparison). No trials assessed all-cause mortality, diabetes-related morbidity or health-related quality of life. Only one trial assessed patients' treatment satisfaction and showed no substantial differences between the addition of either glimepiride or metformin and glimepiride to insulin compared with insulin monotherapy.Insulin-sulphonylurea combination therapy (CT) compared with insulin monotherapy (IM) showed a MD in glycosylated haemoglobin A1c (HbA1c) of -1% (95% confidence interval (CI) -1.6 to -0.5); P < 0.01; 316 participants; 9 trials; low-quality evidence. Insulin-metformin CT compared with IM showed a MD in HbA1c of -0.9% (95% CI -1.2 to -0.5); P < 0.01; 698 participants; 9 trials; low-quality evidence. We could not pool the results of adding pioglitazone to insulin. Insulin combined with alpha-glucosidase inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.2); P < 0.01; 448 participants; 3 trials; low-quality evidence). Insulin combined with DPP-4 inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.4); P < 0.01; 265 participants; 2 trials; low quality evidence. In most trials the participants with CT needed less insulin, whereas insulin requirements increased or remained stable in participants with IM.We did not perform a meta-analysis for hypoglycaemic events because the included studies used different definitions.. In most trials the insulin-sulphonylurea combination resulted in a higher number of mild episodes of hypoglycaemia, compared to the IM group (range: 2.2 to 6.1 episodes per participant in CT versus 2.0 to 2.6 episodes per participant in IM; low-quality evidence). Pioglitazone CT also resulted in more mild to moderate hypoglycaemic episodes compared with IM (range 15 to 90 episodes versus 9 to 75 episodes, respectively; low-quality evidence. The trials that reported hypoglycaemic episodes in the other combinations found comparable numbers of mild to moderate hypoglycaemic events (low-quality evidence).The addition of sulphonylureas resulted in an additional weight gain of 0.4 kg to 1.9 kg versus -0.8 kg to 2.1 kg in the IM group (220 participants; 7 trials; low-quality evidence). Pioglitazone CT caused more weight gain compared to IM: MD 3.8 kg (95% CI 3.0 to 4.6); P < 0.01; 288 participants; 2 trials; low-quality evidence. Metformin CT was associated with weight loss: MD -2.1 kg (95% CI -3.2 to -1.1), P < 0.01; 615 participants; 7 trials; low-quality evidence). DPP-4 inhibitors CT showed weight gain of -0.7 to 1.3 kg versus 0.6 to 1.1 kg in the IM group (362 participants; 2 trials; low-quality evidence). Alpha-glucosidase CT compared to IM showed a MD of -0.5 kg (95% CI -1.2 to 0.3); P = 0.26; 241 participants; 2 trials; low-quality evidence.Users of metformin CT (range 7% to 67% versus 5% to 16%), and alpha-glucosidase inhibitors CT (14% to 75% versus 4% to 35%) experienced more gastro-intestinal adverse effects compared to participants on IM. Two trials reported a higher frequency of oedema with the use of pioglitazone CT (range: 16% to 18% versus 4% to 7% IM).

AUTHORS' CONCLUSIONS

The addition of all oral glucose-lowering agents in people with type 2 diabetes and inadequate glycaemic control who are on insulin therapy has positive effects on glycaemic control and insulin requirements. The addition of sulphonylureas results in more hypoglycaemic events. Additional weight gain can only be avoided by adding metformin to insulin. Other well-known adverse effects of oral glucose-lowering agents have to be taken into account when prescribing oral glucose-lowering agents in addition to insulin therapy.

Controlled porosity solubility modulated osmotic pump tablets of gliclazide

A system that can deliver drug at a controlled rate is very important for the treatment of various chronic diseases such as diabetes, asthma, and heart disease. Poorly water-soluble drug with pH-dependent solubility such as gliclazide (GLZ) offers challenges in the controlled-release formulation because of low dissolution rate and poor bioavailability. Solid dispersion (SD) of GLZ consisted of hydroxypropyl cellulose (HPC-SSL) as a polymeric solubilizer was manufactured by hot melt extrusion (HME) technology. Then, controlled porosity osmotic pump (CPOP) tablet of gliclazide was designed to deliver drug in a controlled manner up to 16 h. The developed formulation was optimized for type and level of pore former and coating weight gain. The optimized formulation was found to exhibit zero order kinetics independent of pH and agitation speed but depends on osmotic pressure of dissolution media indicated that mechanism of drug release was osmotic pressure. The in vivo performance prediction of developed formulation using convolution approach revealed that the developed formulation was superior to the existing marketed extended-release formulation in terms of attaining steady state plasma levels and indicated adequate exposure in translating hypoglycemic response. The prototype solubilization method combined with controlled porosity osmotic pump based technique could provide a unique way to increase dissolution rate and bioavailability of many poorly water-soluble, narrow therapeutic index drugs used in diabetes, cardiovascular diseases, etc.

Insulin therapy in type 2 diabetes: what is the evidence?

AIM

To systematically review the literature regarding insulin use in patients with type 2 diabetes mellitus

METHODS

A Medline and Embase search was performed to identify randomized controlled trials (RCT) published in English between 1 January 2000 and 1 April 2008, involving insulin therapy in adults with type 2 diabetes mellitus. The RCTs must comprise at least glycaemic control (glycosylated haemoglobin (HbA1c), postprandial plasma glucose and /or fasting blood glucose (FBG)) and hypoglycaemic events as outcome measurements.

RESULTS

The Pubmed search resulted in 943 hits; the Embase search gave 692 hits. A total of 116 RCTs were selected by title or abstract. Eventually 78 trials met the inclusion criteria. The studies were very diverse and of different quality. They comprised all possible insulin regimens with and without combination with oral medication. Continuing metformin and/or sulphonylurea after start of therapy with basal long-acting insulin results in better glycaemic control with less insulin requirements, less weight gain and less hypoglycaemic events. Long-acting insulin analogues in combination with oral medication are associated with similar glycaemic control but fewer hypoglycaemic episodes compared with NPH insulin. Most of the trials demonstrated better glycaemic control with premix insulin therapy than with a long-acting insulin once daily, but premix insulin causes more hypoglycaemic episodes. Analogue premix provides similar HbA1c, but lower postprandial glucose levels compared with human premix, without increase in hypoglycaemic events or weight gain. Drawing conclusions from the limited number of studies concerning basal-bolus regimen seems not possible. Some studies showed that rapid-acting insulin analogues frequently result in a better HbA1c or postprandial glucose without increase of hypoglycaemia than regular human insulin.

CONCLUSION

A once-daily basal insulin regimen added to oral medication is an ideal starting point. All next steps, from one to two or even more injections per day should be taken very carefully and in thorough deliberation with the patient, who has to comply with such a regimen for many years.

Unmet needs among patients with type 2 diabetes and secondary failure to oral anti-diabetic agents

Secondary failure is defined as a deterioration of glucose control in patients with Type 2 diabetes on oral antidiabetic drugs (OAD), mainly due to the progressive decline in beta-cell function and reduction in insulin secretion. The consequent hyperglycemia is the most important determinant for the development of microvascular and macrovascular complications, so that an early recognition of this phenomenon can improve long-term outcomes. The recent lowering of target glycosylated hemoglobin (HbA1c) levels by international guidelines not only emphasises the importance of tight glycemic control, but also means that secondary failure to OAD will occur much sooner and is almost unavoidable. Accordingly, in the last years, new different therapeutic strategies were explored to improve the treatment of this condition. The aim of this review is to examine current approaches for treating patients with secondary failure, barriers to achieving and maintaining glycemic control, and recent evidence for emerging therapies which may represent a valid therapeutic option in subjects failing on oral hypoglycemic agents by acting mainly, but not only, at a beta-cell level. In particular, we will focus on the co-administration of OAD plus a novel drug class known as incretin mimetics (e.g. exenatide and liraglutide), which target insulin secretion, and on thiazolidinediones, which act on insulin resistance. Only incretin-mimetics have a lowering HbA1c action, due to the improvement in beta-cell function, which is coupled to significant weight loss. Even if these new options seem to improve the outcome of secondary failure, further investigation is needed to confirm positive results in the long term.

Effect of gliclazide modified release on adiponectin, interleukin-6, and tumor necrosis factor-alpha plasma levels in individuals with type 2 diabetes mellitus

OBJECTIVE

The aim of the study was to evaluate the effect of gliclazide modified release (MR) treatment on adiponectin, interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) plasma concentrations in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

24 randomly selected type 2 diabetic patients, aged 61.2 +/- 15.4 years, with poorly controlled glucose level (mean glycated hemoglobin [HbA1c] 7.6 +/- 1.1%) despite treatment with diet and/or oral hypoglycemic agents, were included in the study. All of the patients, after a 2-week run-in period, were given gliclazide MR for 12 weeks. At baseline, and after gliclazide MR treatment, HbA(1c) and plasma concentrations of IL-6, TNF-alpha, and adiponectin were measured.

RESULTS

Gliclazide MR treatment produced significant reductions in fasting plasma glucose (from 7.6 +/- 1.4 to 6.6 +/- 1.2 mmol/L, p < 0.01), HbA(1c) (from 7.6 +/- 1.1 to 6.9 +/- 0.8%, p < 0.01), and plasma IL-6 concentrations (from 2.5 +/- 1.8 to 1.8 +/- 1.2 pg/mL, p < 0.05). A significant increase in plasma adiponectin level was noted (from 6.4 +/- 3.3 to 7.6 +/- 4.4 mug/mL, p < 0.05). Plasma TNF-alpha concentrations and homeostasis model assessment of insulin resistance (HOMA-IR) decreased after treatment, but these changes did not reach statistical significance.

CONCLUSIONS

Gliclazide MR improves glycemic control and, in addition, has a positive influence on the plasma level of some inflammatory markers and adiponectin. Increased plasma adiponectin and decreased plasma IL-6, and TNF-alpha levels may explain, at least in part, the anti-atherogenic action of this drug reported elsewhere.

Insulin monotherapy versus combinations of insulin with oral hypoglycaemic agents in patients with type 2 diabetes mellitus

BACKGROUND

It is unclear whether patients with type 2 diabetes who have poor glycaemic control despite maximal oral hypoglycaemic agents (OHAs) should be commenced on insulin as monotherapy, or insulin combined with oral hypoglycaemic agents (insulin-OHA combination therapy).

OBJECTIVES

To assess the effects of insulin monotherapy versus insulin-OHA combinations therapy.

SEARCH STRATEGY

Eligible studies were identified by searching MEDLINE, EMBASE, and The Cochrane Library. Date of last search: May 2004.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with 2 months minimum follow-up duration comparing insulin monotherapy (all schemes) with insulin-OHA combination therapy.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of study quality were undertaken by three reviewers in pairs.

MAIN RESULTS

Twenty RCTs (mean trial duration 10 months) including 1,811 participants, with mean age 59.8 years and mean known duration of diabetes 9.6 years. Overall, study methodological quality was low. Twenty-eight comparisons in 20 RCTs were ordered according to clinical considerations. No studies assessed diabetes-related morbidity, mortality or total mortality. From 13 studies (21 comparisons), sufficient data were extracted to calculate pooled effects on glycaemic control. Insulin-OHA combination therapy had statistically significant benefits on glycaemic control over insulin monotherapy only when the latter was applied as a once-daily injection of NPH insulin. Conversely, twice-daily insulin monotherapy (NPH or mixed insulin) provided superior glycaemic control to insulin-OHA combination therapy regimens where insulin was administered as a single morning injection. In more conventional comparisons, regimens utilising OHAs with bedtime NPH insulin provided comparable glycaemic control to insulin monotherapy (administered as twice daily, or multiple daily injections). Overall, insulin-OHA combination therapy was associated with a 43% relative reduction in total daily insulin requirement compared to insulin monotherapy. Of the 14 studies (22 comparisons) reporting hypoglycaemia, 13 demonstrated no significant difference in the frequency of symptomatic or biochemical hypoglycaemia between insulin and combination therapy regimens. No significant differences in quality of life related issues were detected. Combination therapy with bedtime NPH insulin resulted in statistically significantly less weight gain compared to insulin monotherapy, provided metformin was used +/-sulphonylurea. In all other comparisons no significant differences with respect to weight gain were detected.

REVIEWERS' CONCLUSIONS

Bedtime NPH insulin combined with oral hypoglycaemic agents provides comparable glycaemic control to insulin monotherapy and is associated with less weight gain if metformin is used.