Drug interactions of clinical importance with antihyperglycaemic agents: an update

The effects of policosanol supplementation on blood glucose: A systematic review and dose-response meta-analysis of randomized controlled trials

Previous studies have assessed how supplementing with policosanol affects blood sugar levels. The outcomes, nevertheless, were not constant. Multiple electronic databases were searched including ISI Web of Science, Cochrane Library, PubMed, Google Scholar, and Scopus until February 9, 2023. To assess the effects of policosanol on glucose, we employed a random-effects or fixed-effects meta-analysis approach to examine the weighted mean differences (WMDs) and associated 95 % confidence intervals (CI) before and after policosanol and placebo administration. The final analysis comprised a total of 25 trials with 2680 participants. Compared to the control group, policosanol supplementation significantly reduced blood glucose levels (WMD: -2.24 mg/dl; 95 % CI: -4.05, -0.42, P = 0.01). Findings from subgroup analysis revealed a significant reduction of policosanol supplementation on glucose levels in period of less than 24 weeks, and in individuals below 50 years of age. Additionally, the reduction was statistically significant in dosage of 10 mg/day. Our dose-response analysis indicates no evidence of a non-linear relationship between policosanol dose and duration and changes in glucose levels (P-nonlinearity = 0.52, and P-nonlinearity = 0.52, respectively). Policosanol supplementation might improve blood glucose. Further trials with more complex designs are required to confirm the findings.

Interactive effect of oral anti-hyperglycaemic or anti-hypertensive drugs on the inhibitory and bactericidal activity of first line anti-TB drugs against M. tuberculosis

Co-existence of life style disorders, like, Diabetes or Hypertension, increases risk of, treatment failure, deaths and developing drug-resistant TB. Concomitant administration of drugs to treat dual/multi-morbidities may alter their effectiveness, in additive/synergistic or adverse/antagonistic manner. We evaluated interactive effect of 7 anti-hyperglycaemic (HG) and 6 anti-hypertensive (HT) drugs on the inhibitory (MICs) and bactericidal (% killing of intracellular bacilli) activities of anti-TB drugs, Isoniazid (INH), Rifampicin (RFM), Ethambutol (EMB) and Streptomycin (STR) against M. tuberculosis. Five anti-HG drugs, namely, Acarbose, Acetohexamide, Glyburide, Repaglinide and Sitagliptin imparted either 'additive' or 'no effect' on the activities (inhibition or % killing) of all the four anti-TB drugs, as evident by their lower FICs (Fractional Inhibitory concentrations) and higher bacterial killing in combination. Metformin and Rosiglitazone, however, exerted adverse effect on the Ethambutol (FICs >2.0). All the six anti-HT drugs, namely, Atenolol, Hydrochlorothiazide, Ramipril, Valsartan, Nifedipine and Verapamil exerted either 'additive'/'synergistic' or 'no effect' on the activities of anti-TB drugs. These findings may help clinicians to select safe and helpful anti-HG or anti-HT drugs for TB patients, if, suffering with diabetes or hypertension like co-morbidities and receiving DOTs (a set regimen for the treatment of TB based on the WHO guidelines).

The antihyperglycemic effect of pulsed electric field-extracted polysaccharide of Kaempferia elegans officinale on streptozotocin induced diabetic mice

Kaempferia elegans polysaccharide (KEP) was extracted using a high-voltage pulsed electric field-assisted hot water method. Its physicochemical properties, in vitro activity and hypoglycemic effect was investigated. Experiments were undertaken with diabetic mice models and the potential mechanism of KEP to improve blood glucose levels was unveiled through measurements of relevant indicators in the serum and liver of the mice. Results showed that KEP is mainly composed of glucose, rhamnose, arabinose, and galactose. It has certain DPPH and ABTS free radical scavenging ability and good α-glucosidase inhibitory ability, indicating that KEP has the potential to improve blood glucose levels in diabetes patients. The experimental results of KEP treatment on mice showed that KEP could control the continuous increase of fasting blood glucose levels. The potential mechanisms behind this blood glucose level control composes of (1) increasing the glucokinase and C peptide levels and decreasing Glucose-6-phosphatase content for improving key enzyme activity in the glucose metabolism pathway. This promotes the consumption of blood glucose during glycolysis, thereby inhibiting the production of endogenous glucose in gluconeogenesis pathway; (2) reducing triglyceride, total cholesterol, low density lipoprotein cholesterol, and increasing high density lipoprotein cholesterol content, for regulating blood lipid indicators to normal levels; and (3) by improving the activities of catalase, glutathione peroxidase, and antioxidant enzymes superoxide dismutase for further improving the antioxidant defense system in the body to reduce blood glucose.

Concurrent Use of Oral Anticoagulants and Sulfonylureas in Individuals With Type 2 Diabetes and Risk of Hypoglycemia: A UK Population-Based Cohort Study

Objective

To investigate the association of concurrent use of oral anticoagulants (OACs) and sulfonylureas and the risk of hypoglycemia in individuals with type 2 diabetes mellitus (T2DM).

Research Design and Methods

A retrospective cohort study was conducted between 2001 and 2017 using electronic primary healthcare data from the IQVIA Medical Research Data (IMRD) that incorporates data supplied by The Health Improvement Network (THIN), a propriety database of Cegedim SA. Individuals with T2DM who received OAC prescription and sulfonylureas were included. We compared the risk of hypoglycemia with sulfonylureas and OACs using propensity score matching and Cox regression.

Results

109,040 individuals using warfarin and sulfonylureas and 77,296 using direct oral anticoagulants (DOACs) and sulfonylureas were identified and included. There were 285 hypoglycemia events in the warfarin with sulfonylureas group (incidence rate = 17.8 per 1,000 person-years), while in the sulfonylureas only, 304 hypoglycemia events were observed (incidence rate = 14.4 per 1,000 person-years). There were 14 hypoglycemic events in the DOACs with sulfonylureas group (incidence rates = 14.8 per 1,000 person-years), while in the sulfonylureas alone group, 60 hypoglycemia events were observed (incidence rate =23.7 per 1,000 person-years). Concurrent use of warfarin and sulfonylureas was associated with increased risk of hypoglycemia compared with sulfonylureas alone (HR 1.38; 95% CI 1.10-1.75). However, we found no evidence of an association between concurrent use of DOACs and sulfonylureas and risk of hypoglycemia (HR 0.54; 95% CI, 0.27-1.10) when compared with sulfonylureas only.

Conclusions

We provide real-world evidence of possible drug-drug interactions between warfarin and sulfonylureas. The decision to prescribe warfarin with coexistent sulfonylureas to individuals with T2DM should be carefully evaluated in the context of other risk factors of hypoglycemia, and availability of alternative medications.

Honey polyphenolic fraction inhibits cyclooxygenase-2 expression via upregulation of microRNA-26a-5p expression in pancreatic islets

Objectives

Honey total polyphenolic fraction (HTPF) is reported to have anti-disease potential, however the role of HTPF in the regulation of microRNAs (miRNAs) has never been investigated. This study was undertaken to investigate the potential of HTPF against inflammation via regulation of miRNAs in pancreatic islets of Langerhans.

Methods

Pancreatic islets were isolated from C57BL/6 mice and HTPF was purified from honey. Bioinformatics algorithms were used to determine miRNA target genes. Expression of miRNA and mRNA was determined using their specific taqman assays. Pairing between miRNA and 3′ untranslated region (3′UTR) of mRNA was confirmed using luciferase reporter clone containing the 3′UTR of mRNA sequences and results were verified by transfection of mouse pancreatic β-cell line Min6 with miRNA inhibitors.

Results

The data showed that mmu-miR-26a-5p is a direct regulator of cyclooxygenase-2 (COX-2) expression and HTPF inhibits COX-2 expression or prostaglandin E2 (PGE2) production via up-regulating mmu-miR-26a-5p expression. Transfection of islets with anti-miR-26a-5p significantly enhanced COX-2 expression and PGE2 production ( p < .01), while HTPF treatment significantly inhibited anti-miR-26a-5p transfection-induced COX-2 expression or PGE2 production ( p < .05). These findings were further verified in pancreatic β-cells Min6. Moreover, the data also determined that HTPF also inhibits glucose-induced nuclear transcription factor (NF)-κB activity.

Conclusion

HTPF suppresses glucose-induced PGE2 production and activation of NF-κB via negative regulation of COX-2 and mmu-miR26a-5p. These novel pharmacological actions of HTPF on glucose-stimulated pancreatic islets provide new suggestions that HTPF or HTPF-derived compounds inhibit glucose induced inflammation in pancreas by up-regulating the expression of microRNAs.

Hypoglycemia Associated With Drug-Drug Interactions in Patients With Type 2 Diabetes Mellitus Using Dipeptidylpeptidase-4 Inhibitors

Background: Dipeptidylpeptidase-4 inhibitors (DPP-4i′s) are considered to be safe for patients with type 2 diabetes mellitus (T2DM). However, little is known about drug–drug interactions between DPP-4i′s and concurrent medications.

Methods: Data on patients using DPP-4i′s for T2DM during 2011–2017 were retrieved from Chang Gung Research database provided by Chang Gung Memorial Hospital. Patients were excluded if they were aged <30 years or >90 years; had incomplete demographic data; had insulinoma; or had records of concomitant insulin use. A generalized estimating equation–based Poisson model was employed for statistical analysis. The primary outcome was hypoglycemia events.

Results: We retrieved data on a total of 97,227 patients using DPP-4i′s. After patients were excluded according to the mentioned criteria, the remaining 77,047 DPP-4i users were studied (mean age 64 ± 12 years, men 54.4%). The most common medications coprescribed with DPP4is over all person-quarters were acetaminophen, simvastatin, fluvastatin, and colchicine (all >20,000 person-quarters). The combinations of a DPP-4i with bumetanide, captopril, colchicine, acetaminophen, cotrimoxazole, and pantoprazole were associated with an increased risk of hypoglycemia. Compared with the ratios observed for person-quarters of DPP-4i use alone (reference category), the adjusted prevalence ratios per 100 person-years of hypoglycemia for person-quarters of DPP-4i use in combination with bumetanide, captopril, colchicine, acetaminophen, cotrimoxazole, and pantoprazole were 2.44 (95% confidence interval [CI], 1.78–3.36), 2.97 (95% CI, 2.26–3.90), 1.87 (95% CI, 1.44–2.42), 2.83 (95% CI, 2.44–3.29), 2.27 (95% CI, 1.27–4.04), and 3.03 (95% CI, 1.96–4.68), respectively.

Conclusion: Among patients taking DPP-4i′s for T2DM, concurrent use of such inhibitors with bumetanide, captopril, acetaminophen, and pantoprazole was associated with an increased risk of hypoglycemia compared with the use of DPP-4i′s alone. Physicians prescribing DPP-4i′s should consider the potential risks associated with their concomitant use with other drugs.

Careful use to minimize adverse events of oral antidiabetic medications in the elderly

INTRODUCTION

An increasing number of older patients has type 2 diabetes treated with different oral antidiabetic agents whose safety may raise concern considering some particularities of a heterogeneous elderly population.

AREAS COVERED

This article discusses some characteristics of older patients that could increase the risk of adverse events, with a focus on hypoglycemia. It describes the most frequent and/or severe complications reported in the elderly in both randomized controlled trials and observational studies with metformin, sulfonylureas, meglitinides, alpha-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4 inhibitors (gliptins) and sodium-glucose cotransporter type 2 inhibitors (gliflozins).

EXPERT OPINION

Old patients may present comorbidities (renal impairment, vascular disease, heart failure, risk of dehydration, osteoporosis, cognitive dysfunction) that could increase the risk of severe adverse events. Sulfonylureas (and meglitinides) induce hypoglycemia, which may be associated with falls/fractures and cardiovascular events. Medications lacking hypoglycemia should be preferred. Gliptins appear to have the best tolerance/safety profile whereas gliflozins exert a cardiorenal protection. However, data are lacking in very old or frailty old patients so that caution and appropriate supervision of such patients are required. Taking advantage of a large choice of pharmacotherapies, personalized treatment is recommended based upon both drug safety profiles and old patient individual characteristics.

Unravelling the involvement of gut microbiota in type 2 diabetes mellitus

Type 2 diabetes mellitus is the most prevalent metabolic disorder characterized by hyperglycemia, hyperlipidemia as well as insulin resistance and is affecting the lives of a huge population across the globe. Genetic mutations, obesity and lack of physical activity constitute the possible factors that can lead to onset and progression of this disorder. However, there is another major factor that can be the root cause of type 2 diabetes mellitus and that is an imbalance in the microorganisms that inhabit the gut. The gut microbiome is a vital component that needs to be given significant attention because any "dysbiosis" in the colonic microorganisms can transform the host from a state of health to a state of disease. This transformation is quite obvious since the gut barrier integrity, host metabolism such as sensitivity to insulin and maintaining blood glucose level are carried out by the tiny organisms inhabiting our intestine. In fact, the normal functioning of the human body is accredited to the microbes, particularly the bacteria, because they generate their metabolites that communicate with host cells and maintain normal physiology. Giving importance to gut health is, therefore, necessary to prevent metabolic diseases that can be maintained by the intake of prebiotics, probiotics, synbiotics along with healthy diet. The tiny microorganisms in the gut that keep our body free of disorders such as type 2 diabetes mellitus need to be in a state of 'eubiosis', else the consequences of disturbance in gut microbes can progress to serious complications in the host.

2020 Consensus of Taiwan Society of Cardiology on the pharmacological management of patients with type 2 diabetes and cardiovascular diseases

The global incidence and prevalence of type 2 diabetes have been escalating in recent decades. The total diabetic population is expected to increase from 415 million in 2015 to 642 million by 2040. Patients with type 2 diabetes have an increased risk of atherosclerotic cardiovascular disease (ASCVD). About two-thirds of patients with type 2 diabetes died of ASCVD. The association between hyperglycemia and elevated cardiovascular (CV) risk has been demonstrated in multiple cohort studies. However, clinical trials of intensive glucose reduction by conventional antidiabetic agents did not significantly reduce macrovascular outcomes.In December 2008, U.S. Food and Drug Administration issued a mandate that every new antidiabetic agent requires rigorous assessments of its CV safety. Thereafter, more than 200,000 patients have been enrolled in a number of randomized controlled trials (RCTs). These trials were initially designed to prove noninferiority. It turned out that some of these trials demonstrated superiority of some new antidiabetic agents versus placebo in reducing CV endpoints, including macrovascular events, renal events, and heart failure. These results are important in clinical practice and also provide an opportunity for academic society to formulate treatment guidelines or consensus to provide specific recommendations for glucose control in various CV diseases.In 2018, the Taiwan Society of Cardiology (TSOC) and the Diabetes Association of Republic of China (DAROC) published the first joint consensus on the "Pharmacological Management of Patients with Type 2 Diabetes and Cardiovascular Diseases." In 2020, TSOC appointed a new consensus group to revise the previous version. The updated 2020 consensus was comprised of 5 major parts: (1) treatment of diabetes in patients with multiple risk factors, (2) treatment of diabetes in patients with coronary heart disease, (3) treatment of diabetes in patients with stage 3 chronic kidney disease, (4) treatment of diabetes in patients with a history of stroke, and (5) treatment of diabetes in patients with heart failure. The members of the consensus group thoroughly reviewed all the evidence, mainly RCTs, and also included meta-analyses and real-world evidence. The treatment targets of HbA1c were finalized. The antidiabetic agents were ranked according to their clinical evidence. The consensus is not mandatory. The final decision may need to be individualized and based on clinicians' discretion.

The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose-response meta-analysis of randomized controlled trials

Studies regarding the influence of green coffee extract (GCE) on blood glucose levels are conflicting. Thus, we sought to conduct a meta-analysis and systematic review of all available randomized controlled trials (RCTs) to quantify the effects of GCE and CGA intervention on blood glucose and insulin levels. We performed systematic online searches in Scopus, Web of science, and PubMed databases, from inception to July 2019. Data were combined analyzed using a random effects model (Der Simonian-Laird method) and reported as weighted mean differences (WMD). Ten trials reported the influences of GCE on FBS and insulin and were subsequently entered into the meta-analysis. Combined results highlighted that FBS was significantly altered after GCE consumption (WMD: -1.791 mg/dl, 95% CI -3.404, -0.177), with no significant heterogeneity among the studies (I² = 35.0%, p = .128). However, overall results demonstrated that GCE administration did not result in any significant alteration in insulin levels (WMD: -0.925 μU/ml, 95% CI:-1.915, 0.064), with significant heterogeneity found across studies (I² = 87.9%). In sub-group analysis, insulin levels were significantly reduced when GCE was supplemented in dosages of ≥400 mg/day (WMD:-1.942 mg/dl, 95% CI:-1.184, -0.975; I² = 0.0%). The results of present study support the use of GCE for the enhancement of blood glucose, while subgroup analysis highlighted significant improvements in insulin levels when GCE is supplemented in doses ≥400 mg/day.

Glucose-lowering and hypolipidemic activities of polysaccharides from Cordyceps taii in streptozotocin-induced diabetic mice

Background

Hyperglycemia and dyslipidemia are classic features of patients with diabetes mellitus (DM). Cordyceps taii, a folk medicinal fungus native to southern China, possesses various pharmacological activities. This study aimed to assess the glucose-lowering and hypolipidemic effects of polysaccharides from C. taii (CTP) in streptozotocin (STZ)-induced diabetic mice.

Methods

Kunming mice were intraperitoneally injected with STZ at a dose of 100 mg/kg body weight. After induction of diabetes, diabetic mice were randomly divided into five groups: diabetic mellitus group (DM), metformin-treated group, low, medium, and high-dose CTP-treated group (CTP-L, CTP-M, and CTP-H). Normal mice served as the control group. After treatment for 28 days, body weight, fasting serum insulin (FSI), fasting blood glucose (FBG), homeostasis model assessment-insulin resistance (HOMA-IR), triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP) levels were measured. Histological analysis of pancreatic tissue and immune organ indices was also performed to evaluate the anti-diabetes effect of CTP. SPSS (version 21.0) software was used for statistical analysis, and statistical differences were considered significant at p < 0.05.

Results

Compared with the DM group, the body weight and FSI level of CTP-H group increased by 36.13 and 32.47%, whereas the FBG and HOMA-IR decreased by 56.79 and 42.78%, respectively (p < 0.05). Histopathological examination of the pancreas revealed that CTP improved and repaired the impaired islet β-cells in pancreatic tissue. Compared with the DM group, the levels of TC, TG, and LDL-C decreased by 13.84, 31.87, and 36.61%, whereas that of HDL-C increased by 28.60% in CTP-H (p < 0.05). Further study showed that the thymus index in CTP-H was elevated by approximately 54.96%, and the secretion of pro-inflammatory cytokines TNF-α, IL-6, and CRP was inhibited by approximately 19.97, 34.46, and 35.41%, respectively (p < 0.05).

Conclusion

The anti-diabetes effect of CTP is closely associated with immunoregulation and anti-inflammation, and CTP may be considered as a therapeutic drug or functional food for DM intervention.

Impact of Saskatoon berry powder on insulin resistance and relationship with intestinal microbiota in high fat-high sucrose diet-induced obese mice

The present study examined the impact of Saskatoon berry powder (SBp) on insulin resistance, inflammation and intestinal microbiota in diet-induced obese mice. Male C57 BL/6 J mice were fed control diet, high fat-high sucrose (HFHS) diet or HFHS+5% SBp (HFHS+B) diet for 15 weeks. The composition of fecal bacterial community was characterized using the Illumina sequencing of V4 region of 16S rRNA gene. HFHS diet increased body weight, fasting plasma glucose, cholesterol, triglycerides, insulin, homeostatic model assessment-insulin resistance, monocyte adhesion, tumor necrosis factor-α, plasminogen activator inhibitor-1, monocyte chemotactic protein-1, intracellular cell adhesion molecule-1, urokinase plasminogen activator and its receptor in plasma or aortae compared to the control diet. HFHS+B diet postponed the increase in body weight, suppressed HFHS diet-induced disorders in the metabolic and inflammatory variables. The ratio of Firmicutes/Bacteroidetes in the HFHS group was higher than that in the control group (P<.01), and that in the HFHS+B group was lower than that in the HFHS group (P<.05). The abundances of S24-7 family negatively correlated with body weight and tested metabolic or inflammatory variables. The results suggest that SBp attenuated HFHS diet-induced metabolic disorders and vascular inflammation in gut microbiota in mice.

Therapeutic effects of ethanolic extract from the green cocoon shell of silkworm Bombyx mori on type 2 diabetic mice and its hypoglycaemic mechanism

Diabetes mellitus is a clinically complex disease characterized by hyperglycaemia with disturbances in carbohydrate, fat and protein metabolism. The aim of this study was to determine the therapeutic effect of ethanolic extract (EE) from the green cocoon sericin layer of silkworm Bombyx mori on mice with type 2 diabetes mellitus (T2DM) and its hypoglycaemic mechanisms. The results showed that oral EE for 7 weeks had significant ameliorative effects on all the biochemical parameters studied in vivo. The levels of oral glucose tolerance and insulin tolerance were significantly improved. The hypoglycaemic rate in the 350 mg kg^-1 high dosage group was 39.38%. The levels of nuclear factor kappa B (NFκB), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) in the high dosage EE-treated group were significantly reduced, while activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were obviously increased. The islet area and the number of insulin-positive beta cells increased significantly in the high dose group. Furthermore, expression levels of insulin receptor (IR), insulin receptor substrate (IRS), phosphatidylinositide 3-kinase (PI3K), p-Akt and phospho-glycogen synthase kinase-3β (p-GSK3β) involved in insulin signalling were increased. Adenosine 5'-monophosphate-activated protein kinase (AMPK) and glucose transporter 4 (GLUT4) also were activated to regulate glucose metabolism in EE-treated groups. The levels of glucose 6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase (PEPCK) decreased, while the glucokinase (GK) level increased to promote glycolysis. The results clearly indicated that oral EE, especially at a high dose, could improve the glucose metabolism of T2DM by reducing inflammatory reactions, enhancing the antioxidant capacity and insulin sensitivity, and regulating the balance between glycolysis and gluconeogenesis, which means that EE has potential ameliorative effects on T2DM mice.

Diversity, frequency and antifungal resistance of Candida species in patients with type 2 diabetes mellitus

OBJECTIVE

To determine number, species of Candida and Candida resistance to antifungal therapy according to the metabolic control state and the associated salivary changes in patients with type 2 diabetes mellitus (DM2).

MATERIALS AND METHODS

Samples of non-stimulated saliva were collected from 52 patients with DM2. Salivary pH was measured and cultured on Sabouraud glucose agar and the values of CFU/ml were calculated. The species were presumptively identified using CHROMagar Candida^® plates, and identification was confirmed by polymerase chain reaction (PCR). C. albicans isolates were cultured on SGA tetracycline agar with nystatin and fluconazole diffusion disks to measure susceptibility.

RESULTS

Sixty six percent of the yeasts isolated were Candida albicans, followed by C. glabrata (20.7%). In patients with decompensated DM2, there was an inverse association between HbA1c value and salivary pH. At higher levels of salivary acidification, a greater diversity and quantity of yeasts of the genus Candida were observed. With nystatin, higher inhibition was observed at lower pH.

CONCLUSIONS

The antifungal therapies could be more effective if it consider, qualitative salivary characteristics as pH, that could determine the susceptibility of species of Candida to at least to nystatin, which is the most used antifungal for treatment to oral candidiasis in patients with DM2.

Gynura divaricata rich in 3, 5-/4, 5-dicaffeoylquinic acid and chlorogenic acid reduces islet cell apoptosis and improves pancreatic function in type 2 diabetic mice

BACKGROUND

Diabetes mellitus is one of the most common chronic diseases that accompanied by severe complications. Gynura divaricata (GD), a medicinal and edible plant that is usually used for the treatment of diabetes. Therefore, this study investigates the chemical components of GD with hypoglycemic effect and the possible mechanism lowering blood sugar in T2D diabetic mice.

METHODS

The methanol extract of GD was analysed by HPLC-DAD. And then mice with type 2 diabetes induced by a high-fat diet in combination with streptozotocin feed the diet containing lyophilized GD powder for 4 weeks. During this period, fasting blood glucose (FBG) levels and body weight were measured.

RESULTS

GD was rich in four bioactive components of dicaffeoylquinic acid and chlorogenic acid. These components occupied about 2.37% in the GD powder in which the highest level was 3, 5-dicaffeoylquinic acid. Oral GD significantly reduced FBG, fasting serum insulin, and glycosylated serum protein levels, and enhanced antioxidative activities. HE-staining showed that the pathological damage in pancreatic β-cells was ameliorated. An immunohistochemical assay also showed that GD promoted marked pancreatic β-cell regeneration. GD also caused notable increase in GLUT2, GK, MafA, PDX-1, and Bcl-2 as well as reduction in Bax and caspase-3 expression as shown by western blot analysis.

CONCLUSIONS

GD exerts the pronounced hypoglycaemic effect by inhibiting islet cell apoptosis and improving pancreatic function. Therefore, GD might have a potential to improve diabetes.

Actions of metformin and statins on lipid and glucose metabolism and possible benefit of combination therapy

Patients with diabetes type 2 have an increased risk for cardiovascular disease and commonly use combination therapy consisting of the anti-diabetic drug metformin and a cholesterol-lowering statin. However, both drugs act on glucose and lipid metabolism which could lead to adverse effects when used in combination as compared to monotherapy. In this review, the proposed molecular mechanisms of action of statin and metformin therapy in patients with diabetes and dyslipidemia are critically assessed, and a hypothesis for mechanisms underlying interactions between these drugs in combination therapy is developed.

Pharmacokinetics of atorvastatin and sustained-release metformin fixed-dose combination tablets: two randomized, open-label, 2-way crossover studies in healthy male subjects under fed conditions

Two separate studies were conducted to establish bioequivalence (BE) for two doses of atorvastatin/metformin sustained-release (SR) fixed dose combination (FDC) versus the same dosage of the individual component (IC) tablets in healthy male subjects under fed conditions (study 1, BE of atorvastatin/metformin SR 20/500 mg FDC; study 2, BE of atorvastatin/metformin SR 20/750 mg FDC). Each study was a randomized, open-label, single oral dose, two-way crossover design. Serial blood samples were collected pre-dose and up to 36 hours post-dose for atorvastatin and 24 hours for metformin. Plasma concentrations of atorvastatin, 2-OH atorvastatin and metformin were analyzed using a validated liquid chromatography tandem mass-spectrometry. A non-compartmental analysis was used to calculate pharmacokinetic (PK) variables and analysis of variance was performed on the lognormal-transformed PK variables. A total of 75 subjects completed the study 1 (36 subjects) and study 2 (39 subjects). The 90% confidence intervals for the adjusted geometric mean ratio of Cmax and the AUC0-t were within the predefined 0.80 to 1.25 range. The number of subjects reporting at least one adverse event following FDC treatments was comparable to that following IC treatments. The two treatments were well tolerated. Therefore, atorvastatin/metformin SR 20/500 mg and 20/750 mg FDC tablets are expected to be used as alternatives to IC tablets to decrease the pill burden and increase patient compliance.

Development of RP-HPLC, Stability Indicating Method for Degradation Products of Linagliptin in Presence of Metformin HCl by Applying 2 Level Factorial Design; and Identification of Impurity-VII, VIII and IX and Synthesis of Impurity-VII

The novel reverse phase-high performance liquid chromatography (RP-HPLC), stability indicating method was developed for determination of linagliptin (LGP) and its related substances in linagliptin and metformin HCl (MET HCl) tablets by implementing design of experiment to understand the critical method parameters and their relation with critical method attributes; to ensure robustness of the method. The separation of nine specified impurities was achieved with a Zorbax SB-Aq 250 × 4.6 mm, 5 µm column, using gradient elution and a detector wavelength of 225 nm, and validated in accordance with International Conference on Harmonization (ICH) guidelines and found to be accurate, precise, reproducible, robust, and specific. The drug was found to be degrading extensively in heat, humidity, basic, and oxidation conditions and was forming degradation products during stability studies. After slight modification in the buffer and the column, the same method was used for liquid chromatography-mass spectrometry (LC-MS) and ultra-performance liquid chromatography -time-of-flight/mass spectrometry UPLC-TOF/MS analysis, to identify m/z and fragmentation of maximum unspecified degradation products i.e., Impurity-VII (7), Impurity-VIII (8), and Impurity-IX (9) formed during stability studies. Based on the results, a degradation pathway for the drug has been proposed and synthesis of Impurity-VII (7) is also discussed to ensure an in-depth understanding of LGP and its related degradation products and optimum performance during the lifetime of the product.

Analytical Enantio-Separation of Linagliptin in Linagliptin and Metformin HCl Dosage Forms by Applying Two-Level Factorial Design

A novel, stability indicating, reverse phase high-performance liquid chromatography (RP-HPLC) method was developed to determine the S-isomer of linagliptin (LGP) in linagliptin and metformin hydrochloride (MET HCl) tablets (LGP-MET HCl) by implementing design of experiment (DoE), i.e., two-level, full factorial design (2³ + 3 centre points = 11 experiments) to understand the critical method parameters (CMP) and its relation with the critical method attribute (CMA), and to ensure robustness of the method. The separation of the S-isomer, LGP and MET HCl in the presence of their impurities was achieved on Chiralpak® IA-3 (Amylose tris (3, 5-dimethylphenylcarbamate), immobilized on 3 µm silica gel) stationary phase (250 × 4.6 mm, 3 µm) using isocratic elution and detector wavelength at 225 nm with a flow rate of 0.5 mL·min-1, an injection volume of 10 µL with a sample cooler (5 °C) and column oven temperature of 25 °C. Ethanol:Methanol:Monoethanolamine (EtOH:MeOH:MEA) in the ratio of 60:40:0.2 v/v/v was used as a mobile phase. The developed method was validated in accordance with international council for harmonisation (ICH) guidelines and was applied for the estimation of the S-isomer of LGP in LGP-MET HCl tablets. The same method also can be extended for the estimation of the S-isomer in LGP dosage forms.

The efficacy and safety of teneligliptin added to ongoing metformin monotherapy in patients with type 2 diabetes: a randomized study with open label extension

OBJECTIVE

The study investigated the efficacy and tolerability of teneligliptin co-administered to patients with type 2 diabetes mellitus (T2DM) who were inadequately controlled by stable metformin monotherapy ≥ 1000 mg/day.

METHODS

A total of 447 patients from 55 European centers who completed a 14-day screening and 14-day run-in phase, received randomized double-blind treatment with 5, 10, 20 or 40 mg teneligliptin or placebo once daily, for 24 weeks. 364 patients continued treatment in a 28-week open label extension during which they received teneligliptin 20 mg once daily.

RESULTS

Co-administration of teneligliptin (5 to 40 mg) with metformin demonstrated dose-related and statistically significant reductions in HbA1c after 24 weeks (-0.30 to -0.63% placebo adjusted) of double-blind treatment. The greatest reduction in HbA1c was seen with teneligliptin at 40 mg (-0.63%) at Week 24. There was also a dose-dependent increase in proportion of responders achieving HbA1c < 7.0% at this endpoint. Responses were maintained throughout 28 weeks open label treatment with 20 mg teneligliptin. Treatment was well tolerated to Week 52 and the overall incidence of hypoglycemia during 52 weeks was 2.3%.

CONCLUSIONS

Teneligliptin co-administered with metformin produced significant reductions in HbA1c in patients with T2DM without increasing the risk of hypoglycemia.

Pharmacogenetics in type 2 diabetes: influence on response to oral hypoglycemic agents

Type 2 diabetes is one of the leading causes of morbidity and mortality, consuming a significant proportion of public health spending. Oral hypoglycemic agents (OHAs) are the frontline treatment approaches after lifestyle changes. However, huge interindividual variation in response to OHAs results in unnecessary treatment failure. In addition to nongenetic factors, genetic factors are thought to contribute to much of such variability, highlighting the importance of the potential of pharmacogenetics to improve therapeutic outcome. Despite the presence of conflicting results, significant progress has been made in an effort to identify the genetic markers associated with pharmacokinetics, pharmacodynamics, and ultimately therapeutic response and/or adverse outcomes to OHAs. As such, this article presents a comprehensive review of current knowledge on pharmacogenetics of OHAs and provides insights into knowledge gaps and future directions.

Microparticulate and nanoparticulate drug delivery systems for metformin hydrochloride

CONTEXT

Metformin hydrochloride is a biguanide derivative widely used for the treatment of type 2 diabetes, prescribed nearly to 120 million people worldwide. Metformin has a relatively low oral bioavailability (about 50-60%). Although the major effect of metformin is to decrease hepatic glucose output as an antihyperglycemic agent, its inhibitory effects on the proliferation of some cancer cells (e.g. prostate, breast, glioma cells) have been demonstrated in the cell culture studies. Development of novel formulation (e.g. microparticles, nanoparticles) strategies for metformin might be useful to improve its bioavailability, to reduce the dosing frequency, to decrease gastrointestinal side effects and toxicity and to be helpful for effective use of metformin in cancer treatment.

OBJECTIVE

The main aim of this review is to summarize metformin HCl-loaded micro- and nanoparticulate drug delivery systems.

METHOD

The literature was rewieved with regard to the physicochemical, pharmacological properties of metformin, and also its mechanism of action in type 2 diabetes and cancer. In addition, micro- and nanoparticulate drug delivery systems developed for metformin were gathered from the literature and the results were discussed.

CONCLUSION

Metformin is an oral antihyperglycemic agent and also has potential antitumorigenic effects. The repeated applications of high doses of metformin (as immediate release formulations) are needed for an effective treatment due to its low oral bioavailability and short biological half-life. Drug delivery systems are very useful systems to overcome the difficulties associated with conventional dosage forms of metformin and also for its effective use in cancer treatment.

Concomitant drugs with low risks of drug-drug interactions for use in oncology clinical trials

BACKGROUND

Drug-drug interactions (DDIs) may occur with investigational drugs and affect patient safety, trial outcomes, and drug development. A list of preferred drugs with minimal risks of DDIs for treatment of symptoms or comorbidities frequently encountered by cancer patients would be helpful.

METHODS

We reviewed the literature to assess DDIs reported for the main drugs available for treatment of symptoms/comorbidities frequently encountered by cancer patients. Reviews and relevant original articles cited were retrieved and analyzed, and the following data were collected and double-checked: pharmacological properties; effects, if any, of drugs on CYP enzymes, membrane transporters, and QT interval; and involvement in significant DDIs.

RESULTS

A list of preferred drugs with minimal risks of DDIs was compiled.

CONCLUSION

Acknowledging for heterogeneity in data sources, prevention of unexpected DDIs during clinical trials may be improved by using this list of preferred drugs for the management of study patient's symptoms.

Drug-drug interactions with sodium-glucose cotransporters type 2 (SGLT2) inhibitors, new oral glucose-lowering agents for the management of type 2 diabetes mellitus

Inhibitors of sodium-glucose cotransporters type 2 (SGLT2) reduce hyperglycaemia by decreasing renal glucose threshold and thereby increasing urinary glucose excretion. They are proposed as a novel approach for the management of type 2 diabetes mellitus. They have proven their efficacy in reducing glycated haemoglobin, without inducing hypoglycaemia, as monotherapy or in combination with various other glucose-lowering agents, with the add-on value of promoting some weight loss and lowering arterial blood pressure. As they may be used concomitantly with many other drugs, we review the potential drug-drug interactions (DDIs) regarding the three leaders in the class (dapagliglozin, canagliflozin and empagliflozin). Most of the available studies were performed in healthy volunteers and have assessed the pharmacokinetic interferences with a single administration of the SGLT2 inhibitor. The exposure [assessed by peak plasma concentrations (Cmax) and area under the concentration-time curve (AUC)] to each SGLT2 inhibitor tested was not significantly influenced by the concomitant administration of other glucose-lowering agents or cardiovascular agents commonly used in patients with type 2 diabetes. Reciprocally, these medications did not influence the pharmacokinetic parameters of dapagliflozin, canagliflozin or empagliflozin. Some modest changes were not considered as clinically relevant. However, drugs that could specifically interfere with the metabolic pathways of SGLT2 inhibitors [rifampicin, inhibitors or inducers of uridine diphosphate-glucuronosyltransferase (UGT)] may result in significant changes in the exposure of SGLT2 inhibitors, as shown for dapagliflozin and canagliflozin. Potential DDIs in patients with type 2 diabetes receiving chronic treatment with an SGLT2 inhibitor deserve further attention, especially in individuals treated with several medications or in more fragile patients with hepatic and/or renal impairment.

[The use of gliclazide in individualized sulfonylurea therapy]

In addition to the common blood glucose lowering effect, sulfonylurea compounds are different in many aspects from each other. Based on earlier findings the second generation gliclazide has special advantages within this group. Although the number of experimental and clinical observations on gliclazide is continuously increasing, these novel findings are not in the focus anymore due to the appearance of new antidiabetics. This article reviews recent experimental (effect on receptors, the absence of Epac2 activation, antioxidant properties, possible incentive of factors participating in beta-cell differentiation) and pharmacogenomic data, and compares them with clinical observations obtained from gliclazide treatment (hypoglycemias, parameters of cardiovascular outcome). The data underline the advantages of gliclazide, the highly pancreas-selective nature, preservation of the ischemic precondition, favourable hemodynamic properties and potential reduction of the beta-cell loss as compared to other compounds of the group. However, gliclazide is not free from disadvantages characteristic to sulfonylureas in general (blood glucose independent insulin stimulation, beta-cell depletion). Comparing gliclazide with other derivatives of the group, the above data indicate individual benefits for the application when sulfonylurea compound is the drug of choice.

Metformin-induced thyrotropin suppression is not associated with cardiac effects

OBJECTIVE

Metformin treatment may induce a decrease/suppression in serum TSH levels, mimicking sub-clinical hyperthyroidism (SHT). The aim of the present study was to retrospectively evaluate changes in several electrocardiographic indices in euthyroid subjects with diabetes who, after starting metformin treatment, developed a low serum TSH as compared to patients with SHT resulting from an underlying thyroid disease or TSH suppressive treatment with L-thyroxine.

DESIGN

Heart rate, P wave duration, P wave dispersion, QTmax, QTmin and QT-dispersion were assessed in 23 patients with diabetes treated with metformin before and after 6 months of TSH-suppression and in 31 control patients with SHT.

RESULTS

No significant changes in electrocardiographic parameters were observed from baseline to the TSH-suppression measurement. A significant difference in P wave duration (102.9 ± 7.4 vs. 92.1 ± 5.8 ms, p<0.001), P wave dispersion (13.1 ± 3.4 vs. 7.1 ± 3.5 ms, p<0.001), QTmax (399 ± 18 vs. 388 ± 16 ms, p=0.024), QTmin (341 ± 14 vs. 350 ± 17 ms, p=0.038) and QT dispersion (49.9 ± 9.6 vs. 30.9 ± 9.2 ms, p<0.001) were observed between the control group with SHT and the group of diabetic patients with low serum levels of TSH.

CONCLUSIONS

Our results show that the TSH-suppressive effect observed in patients taking metformin is not associated with peripheral markers of thyroid hormone excess, at least at the cardiac level.

Evaluating SGLT2 inhibitors for type 2 diabetes: pharmacokinetic and toxicological considerations

INTRODUCTION

Inhibitors of sodium-glucose cotransporters type 2 (SGLT2), which increase urinary glucose excretion independently of insulin, are proposed as a novel approach for the management of type 2 diabetes mellitus (T2DM).

AREAS COVERED

An extensive literature search was performed to analyze the pharmacokinetic characteristics, toxicological issues and safety concerns of SGLT2 inhibitors in humans. This review focuses on three compounds (dapagliflozin, canagliflozin, empagliflozin) with results obtained in healthy volunteers (including drug-drug interactions), patients with T2DM (single dose and multiple doses) and special populations (those with renal or hepatic impairment).

EXPERT OPINION

The three pharmacological agents share an excellent oral bioavailability, long half-life allowing once-daily administration, low accumulation index and renal clearance, the absence of active metabolites and a limited propensity to drug-drug interactions. No clinically relevant changes in pharmacokinetic parameters were observed in T2DM patients or in patients with mild/moderate renal or hepatic impairment. Adverse events are a slightly increased incidence of mycotic genital and rare benign urinary infections. SGLT2 inhibitors have the potential to reduce several cardiovascular risk factors, and cardiovascular outcome trials are currently ongoing. The best positioning of SGLT2 inhibitors in the armamentarium for treating T2DM is still a matter of debate.

Risk factors contributing to type 2 diabetes and recent advances in the treatment and prevention

Type 2 diabetes is a serious and common chronic disease resulting from a complex inheritance-environment interaction along with other risk factors such as obesity and sedentary lifestyle. Type 2 diabetes and its complications constitute a major worldwide public health problem, affecting almost all populations in both developed and developing countries with high rates of diabetes-related morbidity and mortality. The prevalence of type 2 diabetes has been increasing exponentially, and a high prevalence rate has been observed in developing countries and in populations undergoing "westernization" or modernization. Multiple risk factors of diabetes, delayed diagnosis until micro- and macro-vascular complications arise, life-threatening complications, failure of the current therapies, and financial costs for the treatment of this disease, make it necessary to develop new efficient therapy strategies and appropriate prevention measures for the control of type 2 diabetes. Herein, we summarize our current understanding about the epidemiology of type 2 diabetes, the roles of genes, lifestyle and other factors contributing to rapid increase in the incidence of type 2 diabetes. The core aims are to bring forward the new therapy strategies and cost-effective intervention trials of type 2 diabetes.

A case report of priapism caused by ziprasidon

Priapism is defined as having prolonged (more than 6 h), and usually painful penile erection that occurs without a sexual desire or arousal. Only a very few priapism cases caused by ziprasidone are reported in the literature. In this case report we aimed to present a prolonged penile erection due to use of ziprasidone.

Synergistic interaction between metformin and sulfonylureas on diclofenac-induced antinociception measured using the formalin test in rats

BACKGROUND

There is evidence that biguanides and sulfonylureas block diclofenac-induced antinociception (DIA) in rat models. However, little is known about the interaction between these hypoglycemics with respect to DIA.

OBJECTIVE

To determine whether metformin-sulfonylurea combinations affect DIA during the formalin test.

METHODS

Rats received the appropriate vehicle or diclofenac before 1% formaldehyde was injected into the paw. Rats were also pretreated with vehicle, glibenclamide, glipizide, metformin or glibenclamide⁄metformin and glipizide⁄metformin combinations before the diclofenac and formaldehyde injections, and the effect on antinociception was assessed. Isobolograms of the combinations were constructed to test for a synergistic interaction.

RESULTS

Systemic injection of diclofenac resulted in antinociception during the second phase of the test. Systemic pretreatment with the combinations of glibenclamide (0.56 mg⁄kg to 10 mg⁄kg)⁄metformin (10 mg⁄kg to 180 mg⁄kg) and glipizide (0.56 mg⁄kg to10 mg⁄kg)⁄metformin (10 mg⁄kg to 180 mg⁄kg) blocked DIA. The derived theoretical effective doses for 50% of subjects (ED50) for the glibenclamide⁄metformin and glipizide⁄metformin combinations were 32.52 mg⁄kg and 32.42 mg⁄kg, respectively, and were significantly higher than the actual observed experimental ED50 values (7.57 mg⁄kg and 8.43 mg⁄kg, respectively).

CONCLUSION

Pretreatment with glibenclamide, glipizide or metformin blocked DIA in a dose-dependent manner, and combining either sulfonylurea with metformin produced even greater effects. The observed ED50s for the combinations were approximately fourfold lower than the calculated additive effects. These data indicate that sulfonylureas interact to produce antagonism of DIA. Combination therapy is a common second-line treatment for patients with diabetes and metabolic syndrome, a group that experiences pain from multiple sources. The results suggest that at least some anti-inflammatory agents may not be effective in this group.

Safety, pharmacokinetics and pharmacodynamics of remogliflozin etabonate, a novel SGLT2 inhibitor, and metformin when co-administered in subjects with type 2 diabetes mellitus

Background

The sodium-dependent glucose co-transporter-2 (SGLT2) is expressed in absorptive epithelia of the renal tubules. Remogliflozin etabonate (RE) is the prodrug of remogliflozin, the active entity that inhibits SGLT2. An inhibitor of this pathway would enhance urinary glucose excretion (UGE), and potentially improve plasma glucose concentrations in diabetic patients. RE is intended for use for the treatment of type 2 diabetes mellitus (T2DM) as monotherapy and in combination with existing therapies. Metformin, a dimethylbiguanide, is an effective oral antihyperglycemic agent widely used for the treatment of T2DM.

Methods

This was a randomized, open-label, repeat-dose, two-sequence, cross-over study in 13 subjects with T2DM. Subjects were randomized to one of two treatment sequences in which they received either metformin alone, RE alone, or both over three, 3-day treatment periods separated by two non-treatment intervals of variable duration. On the evening before each treatment period, subjects were admitted and confined to the clinical site for the duration of the 3-day treatment period. Pharmacokinetic, pharmacodynamic (urine glucose and fasting plasma glucose), and safety (adverse events, vital signs, ECG, clinical laboratory parameters including lactic acid) assessments were performed at check-in and throughout the treatment periods. Pharmacokinetic sampling occurred on Day 3 of each treatment period.

Results

This study demonstrated the lack of effect of RE on steady state metformin pharmacokinetics. Metformin did not affect the AUC of RE, remogliflozin, or its active metabolite, GSK279782, although C_max values were slightly lower for remogliflozin and its metabolite after co-administration with metformin compared with administration of RE alone. Metformin did not alter the pharmacodynamic effects (UGE) of RE. Concomitant administration of metformin and RE was well tolerated with minimal hypoglycemia, no serious adverse events, and no increase in lactic acid.

Conclusions

Coadministration of metformin and RE was well tolerated in this study. The results support continued development of RE as a treatment for T2DM.

Trial registration

ClinicalTrials.gov, NCT00376038

Relationship between serum thyrotropin concentrations and metformin therapy in euthyroid patients with type 2 diabetes

AIM

A thyrotropin(TSH)-lowering effect of metformin therapy has been recently reported in patients with type 2 diabetes (T2D) and hypothyroidism. We aimed to evaluate the interplay between metformin therapy and serum TSH concentrations in a group of patients with T2D and normal thyroid function.

PATIENTS AND METHODS

Eight hundred and twenty-eight euthyroid patients with T2D (53% women, mean age 65·9 years, median duration of diabetes 10 years) were retrospectively evaluated. There were 250 patients on metformin treatment (30·2%). Serum concentrations of TSH were measured in all subjects.

RESULTS

Patients on metformin treatment exhibited significantly higher TSH levels [1·63 (1·11-2·24) mU/l] than those found in patients without metformin [1·40 (1·01-2·24) mU/l, P = 0·009]. We found no significant differences in TSH levels in patients who were on therapy with other oral antidiabetics, antihypertensive drugs or hypolipidemic agents in relation to subjects not taking these drugs. Serum TSH was significantly related to gender, body mass index, hyperlipidaemia and the presence of goitre and diabetic macroangiopathy. In multiple regression analysis with TSH as dependent variable, goitre was negatively related to TSH values. Metformin therapy was a nonsignificant variable in this model.

CONCLUSION

In summary, this is the first survey analysing the relationship between metformin and thyroid function in a large cohort of patients with diabetes. Our data do not support the presence of an independent and significant relationship between TSH values and metformin treatment in euthyroid patients with T2D.

The role of osteocalcin in human glucose metabolism: marker or mediator?

Increasing evidence supports an association between the skeleton and energy metabolism. These interactions are mediated by a variety of hormones, cytokines and nutrients. Here, the evidence for a role of osteocalcin in the regulation of glucose metabolism in humans is reviewed. Osteocalcin is a bone matrix protein that regulates hydroxyapatite size and shape through its vitamin-K-dependent, γ-carboxylated form. The concentration of osteocalcin in the circulation is a measure of bone formation. The undercarboxylated form of osteocalcin is active in glucose metabolism in mice. Total serum osteocalcin concentrations in humans are inversely associated with measures of glucose metabolism; however, human data are inconclusive with regard to the role of uncarboxylated osteocalcin in glucose metabolism because most studies do not account for the influence of vitamin K on the proportion of undercarboxylated osteocalcin or differentiate between the total and uncarboxylated forms of osteocalcin. Furthermore, most human studies do not concomitantly measure other bone turnover markers to isolate the role of osteocalcin as a measure of bone formation from its effect on glucose metabolism. Carefully designed studies are required to define the role of osteocalcin and its carboxylated or undercarboxylated forms in the regulation of glucose metabolism in humans.

Type 2 diabetes mellitus: a review of current trends

Type 2 diabetes mellitus (DM) is a chronic metabolic disorder in which prevalence has been increasing steadily all over the world. As a result of this trend, it is fast becoming an epidemic in some countries of the world with the number of people affected expected to double in the next decade due to increase in ageing population, thereby adding to the already existing burden for healthcare providers, especially in poorly developed countries. This review is based on a search of Medline, the Cochrane Database of Systemic Reviews, and citation lists of relevant publications. Subject heading and key words used include type 2 diabetes mellitus, prevalence, current diagnosis, and current treatment. Only articles in English were included. Screening and diagnosis is still based on World Health Organization (WHO) and American Diabetes Association (ADA) criteria which include both clinical and laboratory parameters. No cure has yet been found for the disease; however, treatment modalities include lifestyle modifications, treatment of obesity, oral hypoglycemic agents, and insulin sensitizers like metformin, a biguanide that reduces insulin resistance, is still the recommended first line medication especially for obese patients. Other effective medications include non-sulfonylurea secretagogues, thiazolidinediones, alpha glucosidase inhibitors, and insulin. Recent research into the pathophysiology of type 2 DM has led to the introduction of new medications like glucagon-like peptide 1 analogoues: dipeptidyl peptidase-IV inhibitors, inhibitors of the sodium-glucose cotransporter 2 and 11ß-hydroxysteroid dehydrogenase 1, insulin-releasing glucokinase activators and pancreatic-G-protein-coupled fatty-acid-receptor agonists, glucagon-receptor antagonists, metabolic inhibitors of hepatic glucose output and quick-release bromocriptine. Inhaled insulin was licensed for use in 2006 but has been withdrawn from the market because of low patronage.

Vitamin K-dependent carboxylation of osteocalcin: friend or foe?

Osteocalcin originates from osteoblastic synthesis and is deposited into bone or released into circulation, where it correlates with histological measures of bone formation. The presence of 3 vitamin K-dependent γ carboxyglutamic acid residues is critical for osteocalcin's structure, which appears to regulate the maturation of bone mineral. In humans, the percentage of the circulating osteocalcin that is not γ-carboxylated (percent ucOC) is used as a biomarker of vitamin K status. In contrast, when ucOC is not corrected for total osteocalcin, the interpretation of this measure is confounded by osteoblastic activity, independent of vitamin K. Observational studies using percent ucOC have led to the conclusion that vitamin K insufficiency leads to age-related bone loss. However, clinical trials do not provide overall support for the suggestion that vitamin K supplementation of the general population will reduce bone loss or fracture risk. More recently, results from in vitro and in vivo studies using animal models indicate that ucOC is an active hormone with a positive role in glucose metabolism. By inference, vitamin K, which decreases ucOC, would have a detrimental effect. However, in humans this hypothesis is not supported by the limited data available, nor is it supported by what has been established regarding osteocalcin chemistry. In summary, the specific function of osteocalcin in bone and glucose metabolism has yet to be elucidated.

Saxagliptin plus metformin combination therapy

Metformin is considered to be the first-line drug therapy for the management of Type 2 diabetes. Incretin-based therapies, and especially dipeptidyl peptidase-4 inhibitors, offer new opportunities after failure of metformin. An extensive literature search was performed to analyze all clinical trials combining saxagliptin with metformin. Saxagliptin and metformin may be administered together, either separately or in fixed-dose combination, as saxagliptin added to metformin or as an initial combination. Saxagliptin and metformin are not prone to pharmacokinetic drug-drug interactions and fixed-dose combination allows dosing of one single pill (Kombiglyze^® XR) or two pills (Komboglyze^®) per day. Both compounds exert pharmacodynamic complementary actions. Their coadministration improves blood glucose control (fasting plasma glucose, postprandial glucose and glycated hemoglobin) more potently than either compound separately. Tolerance is good without hypoglycemia, weight gain and further increase in metformin-related gastrointestinal adverse events. The combination saxagliptin plus metformin may be used as first-line or second-line therapy in the management of Type 2 diabetes.

Pharmacokinetics of a fixed-dose combination of atorvastatin and metformin extended release versus concurrent administration of individual formulations: a randomized, open-label, two-treatment, two-period, two-sequence, single-dose, crossover, bioequivalence study

BACKGROUND

Type 2 diabetes mellitus is associated with a 2- to 4-fold increased risk of coronary heart disease (CHD). Combined therapy with an antihyperglycaemic agent and an HMG-CoA reductase inhibitor (statin) is indicated for the treatment of diabetic patients at risk of CHD. Patients with type 2 diabetes are generally considered to be at equivalent cardiovascular disease risk to patients with established CHD, and should have low-density lipoprotein (LDL) cholesterol levels reduced to <100 mg/dL or by 30-40%. Atorvastatin is the drug of choice for lowering LDL cholesterol levels. Metformin is the first therapeutic option in type 2 diabetes patients who are overweight or obese because it may also prevent vascular complications and mortality. Hence, a fixed-dose combination (FDC) of atorvastatin 10 mg and metformin 500 mg extended release (ER) was developed for patients with type 2 diabetes with or without hyperlipidaemia.

OBJECTIVES

This study set out to establish bioequivalence between treatment 1 (test) - atorvastatin/metformin ER 10 mg/500 mg FDC, and treatment 2 (reference) - atorvastatin 10 mg (Lipitor®) and metformin 500 mg (Glucophage® XR) administered concurrently as individual tablets.

METHODS

The study was a randomized, open-label, two-treatment, two-period, two-sequence, single-dose, crossover, bioequivalence study in 40 male subjects of Asian origin aged 18-45 years. The order of receiving the test and reference treatments for each subject during both the periods of the study was determined according to an SAS®-generated randomization schedule. The two treatments were separated by a washout period of 11 days. Blood samples were collected pre-dose and up to 72 hours post-dose in each period for determination of plasma atorvastatin/metformin concentrations and calculation of the respective pharmacokinetic parameters. ANOVA was performed on the lognormal-transformed pharmacokinetic parameters. A 90% confidence interval (CI) for the ratios of the test and reference product averages (least squares means) was calculated for atorvastatin and metformin to establish bioequivalence.

RESULTS

The 90% CIs for atorvastatin and metformin were within the bioequivalence acceptance criteria of 80-125%. The 90% CIs obtained for atorvastatin for maximum plasma concentration (C(max))(,) area under the plasma concentration-time curve (AUC) from time zero to time of last measurable concentration (AUC(last)) and AUC from time zero to infinity (AUC(∞)) were (88.11, 106.93), (91.18, 107.94) and (89.25, 106.60), respectively. The 90% CIs observed for metformin for C(max,) AUC(last,) AUC(∞) and AUC from time zero to 24 hours (AUC(24)) were (113.3, 124.0), (102.65, 117.97), (101.87, 116.82) and (102.44, 117.53), respectively. The two treatments were well tolerated by the study subjects.

CONCLUSION

Atorvastatin/metformin ER 10 mg/500 mg FDC has similar bioavailability to the co-administration of separate atorvastatin 10 mg and metformin 500 mg tablets. The FDC tablets show similar safety and tolerability profiles to their individual components. Therefore, atorvastatin/metformin ER 10 mg/500 mg FDC tablets can be used safely in clinical settings to decrease the pill burden and increase patient compliance with therapy.