Acarbose bioequivalence: Exploration of eligible protocol design.

WHAT IS KNOWN AND OBJECTIVE: Acarbose is a poorly absorbed α-glucosidase inhibitor that acts locally in the intestinal tract. Therefore, the evaluation of its bioequivalence (BE) should be based on pharmacodynamic (PD) rather than pharmacokinetic (PK) endpoints. Currently, there is no consensus on the best method for acarbose BE evaluation. The optimal protocol design regarding dosing time/dose and PD parameters requires further exploration. The aim of the study was to identify an optimum protocol for establishing acarbose BE in healthy Chinese volunteers using PD endpoints. METHODS: Three pilot studies were conducted in healthy Chinese subjects. Study 1 was an open, randomized, two-period crossover study using the reference (R) drug at the dose of 1 × 50 mg. Study 1 aimed to determine appropriate dosing time by comparing the PD effect of acarbose between two administration methods. One method was concomitant administration of sucrose and acarbose, and another method was acarbose administration 10 min before sucrose. Study 2 was an open, randomized, three-period crossover study. Subjects were given the R drug at the dose of 1 × 50 mg, 2 × 50 mg or 3 × 50 mg in a random sequence. The aim of Study 2 was to identify a reasonable dose of acarbose in the BE study. Study 3 was conducted with an open, randomized, three-period crossover design using the test (T) or R drug in an R-T-R sequence at the dose of 2 × 50 mg. Study 3 aimed to compare the BE between the R and T drug and determine intra-individual variation. Twelve subjects were recruited in Study 1, Study 2 and Study 3, respectively, with a one-week washout period. Serum glucose and insulin concentrations were determined after sucrose administration (baseline) and sucrose/acarbose co-administration. RESULTS AND DISCUSSION: In Study 1, no significant differences in PD parameters were found between the two administration methods. The results of Study 2 revealed that the optimal dose was between 1 × 50 mg and 2 × 50 mg. The comparison of PD parameters indicated that the rectifying method could distinguish between different formulations. Study 3 showed that the geometric mean ratios of Cmax, r , AUC0-2 h, r and AUC0-4 h, r were 90.06%, 84.55% and 84.21%, respectively, using the rectifying method. The 90% CIs of Cmax, r were within acceptance limits (80.00%-125.00%), whereas that of AUC0-2 h, r and AUC0-4 h, r were out of the range. The intra-individual variation was approximately 21% for R formulation. Based on the variation, the number of subjects needed to identify formulation differences in the pivotal study would be 55 with 90% power at the 5% level of significance. WHAT IS NEW AND CONCLUSION: The results from our study manifested that a randomized, balanced, two-way crossover design was eligible to evaluate acarbose BE. The appropriate dosing time was concomitant administration of sucrose and acarbose, and the optimal dose was 2 × 50 mg. The rectifying method exhibited preferable sensitivity and applicability in acarbose BE evaluation. A practical sample size of the pivotal study would be 55. These results may help to provide new insights into the protocol design of acarbose BE study.

Pharmacodynamic comparison of acarbose tablets in Chinese healthy volunteers under chewing and swallowing conditions.

WHAT IS KNOWN AND OBJECTIVE: Acarbose can efficiently block glucose absorption in the intestine as an alpha-glucosidase inhibitor. It is currently manufactured in several oral dosage forms, with the most common types being tablets and chewable tablets. The acarbose tablet (Glucobay® , 50 mg, Bayer) package insert gives instructions for either directly swallowing or chewing then swallowing. This study compared the pharmacodynamic effects of a single formulation of acarbose tablets under these two different administration routes. METHODS: This randomized, crossover study enrolled 24 healthy subjects who were instructed to chew (C group) or swallow (S group) the acarbose tablet. Glucose levels were monitored in subjects for up to 4 h following administration of 75 g of sucrose to establish a baseline firstly, after which subjects in the C and S groups were administered 50- or 100- mg of acarbose along with 75 g of sucrose. Then, subjects entered a 1-week washout period before being crossed over to the alternate dosing route. RESULTS AND DISCUSSION: Compared with the S group, the C group had a lower maximum concentration of serum glucose (Cmax ) and areas under the concentration-time curve (AUC0-2 , AUC0-1.5 ). In addition, the maximum reduction in serum glucose (ΔCmax ) and the reduction in the AUC (AUEC0-1.5 ) were both increased in the S group. This occurred at both the 50 mg and 100 mg dosages. These results indicate that fluctuations in blood glucose were lower following chewing of the acarbose tablet. Both administration routes exhibited similar safety and tolerance profiles. WHAT IS NEW AND CONCLUSION: In summary, chewing acarbose tablets appears to induce a superior glycaemic-controlling effect compared with swallowing them directly, at least with a single dose. It will be important to inform both clinicians and patients about these differences between the two administrations so that informed clinical decisions can be made, as numerous patients with diabetes are inclined to directly swallow acarbose tablets for convenience.

Taxifolin prevents postprandial hyperglycemia by regulating the activity of α-amylase: Evidence from an in vivo and in silico studies.

There has been a dramatic increase in the prevalence of diabetes mellitus (DM) and its associated complications globally. The postprandial stage of DM involves prompt elevation in the levels of blood glucose and α-amylase, a carbohydrate-metabolizing enzyme is mainly involved in the regulation of postprandial hyperglycemia. This study was designed to assess the ability of a well-known flavonoid, taxifolin (TFN), against postprandial hyperglycemia and its inhibitory effects on α-amylase activity through the assessment of therapeutic potentials of TFN in an alloxan-induced diabetic animal model. The binding potential TFN with an α-amylase receptor was also investigated through molecular dynamics (MD) simulation and docking of to compare the binding affinities and energies of TFN and standard drug acarbose (ACB) with target enzyme. TFN significantly improved the postprandial hyperglycemia, lipid profile, and serum levels of α-amylase, lipase, and C-reactive protein in a dose-dependent manner when compared with that of either DM-induced and ACB-treated alloxan-induced diabetic rats. Moreover, TFN also enhanced the anti-oxidant status and normal functioning of the liver in alloxan-induced diabetic rats more efficiently as compared to that of ACB-treated alloxan-induced diabetic rats. Therapeutic potentials of TFN were also verified by MD simulation and docking results, which exhibited that the binding energy and affinity of TFN to bind with receptor was significantly higher as compared to that of ACB. Hence, the results of this study signify that TFN might be a potent inhibitor of α-amylase that has the potential to regulate the postprandial hyperglycemia along with its anti-inflammatory and anti-oxidant properties during the treatment of DM.

Use of dipeptidyl peptidase-4 inhibitors and the risk of arthralgia: Population-based cohort and nested case-control studies.

PURPOSE: The objective of this study was to investigate the association between the administration of dipeptidyl peptidase-4 (DPP-4) inhibitors (cumulative duration, timing, and individual substance) and the risk of arthralgia by using a nationwide database with two methodological approaches including cohort and nested case-control study designs. METHODS: Using Taiwan's National Health Insurance Research Database, we identified patients who were newly prescribed with DPP-4 inhibitors, thiazolidinediones (TZDs), or acarbose between 1 March 2009 and 31 December 2012. The exposure of studied drugs was categorized into five exclusive categories: DPP-4 inhibitor, TZD, acarbose, combined use, or non-use, and assessed in a time-varying manner. Time-dependent Cox proportional hazard models were used to estimate the association between DPP-4 inhibitors and the risk of arthralgia. Particularly, we tested the impact of different cumulative duration, timing, and individual substance of DPP-4 inhibitors use on risk of arthralgia. A corresponding nested case-control study using conditional logistic regression was conducted to verify this association. RESULTS: An increased risk of arthralgia was observed during the first year after initiating DPP-4 inhibitors (adjusted Hazard Ratio = 1.35; 95% confidence interval [CI], 1.04-1.75) but the risk declined with cumulative use. This duration-response relation was not found in TZDs use and acarbose use. In the nested case-control study, there was a slightly increased risk of arthralgia (aOR = 1.08; 95% CI, 1.04-1.12) associated with current DPP-4 inhibitor use. CONCLUSION: A relatively higher risk of arthralgia was associated with the initial administration of DPP-4 inhibitors, however, the risk declined among long-term users.

A randomized, crossover study of the acute effects of acarbose and gastric distension, alone and combined, on postprandial blood pressure in healthy older adults.

BACKGROUND: Postprandial hypotension (PPH) occurs frequently in the elderly and patients with type 2 diabetes, and lacks a satisfactory treatment. Gastric distension and the α-glucosidase inhibitor, acarbose, may attenuate the postprandial fall in blood pressure (BP) by complementary mechanisms. We aimed to determine whether gastric distension and acarbose have additive effects to attenuate the fall in BP induced by oral sucrose. METHODS: Ten healthy older adults (74.0 ± 1.4 yr) had measurements of BP and superior mesenteric artery (SMA) blood flow for 120 min after receiving either (i) the 'study drink' of 100 g sucrose in 300 mL of water (control treatment), (ii) a 300 mL water 'preload' 15 min before the 'study drink' (distension treatment), (iii) 100 mg acarbose dissolved in the 'study drink' (acarbose treatment) or (iv) a 300 ml water 'preload' 15 min before 100 mg acarbose dissolved in the 'study drink' (acarbose and distension treatment). RESULTS: The area under the curve (AUC)0-120min for mean arterial pressure (MAP) was greater (P = 0.005) and the maximum fall in MAP was less (P = 0.006) during treatments with acarbose. Gastric distension did not affect the MAP-AUC0-120min response to acarbose (P = 0.44) and there was no effect of gastric distension alone (P = 0.68). Both acarbose treatments attenuated the rise in SMA blood flow (P = 0.003), whereas gastric distension had no effect. CONCLUSIONS: In healthy older adults, acarbose (100 mg), but not gastric distension, attenuates the fall in BP and rise in SMA blood flow after oral sucrose. The observations support the use of acarbose, but not gastric distension, to attenuate a postprandial fall in BP. TRIAL REGISTRATION: The study was retrospectively registered at ( ACTRN12618000152224 ) on February 02nd 2018.

Effect of race on the glycaemic response to sitagliptin: Insights from the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS).

AIM: Pooled efficacy studies suggest that glycaemic responses to dipeptidyl-peptidase 4 inhibitors in type 2 diabetes are greatest in Asians, who may also respond better to alpha-glucosidase inhibitors. We assessed the glycaemic impact of sitagliptin by race in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), and whether this was enhanced in Asians with concomitant acarbose therapy. MATERIALS AND METHODS: TECOS enrolled 14 671 patients with type 2 diabetes, cardiovascular disease and HbA1c of 48-64 mmol/mol (6.5%-8.0%), and randomized them, double-blind, to sitagliptin or placebo. There were 3265 patients (22.3%) from Asian countries. Background glucose-lowering therapies were unaltered for the first 4 months post randomization unless clinically essential, facilitating comparison of sitagliptin-associated effects in self-identified East Asian, Other (South) Asian, White Caucasian, Hispanic, Black and Indigenous groups. RESULTS: Median baseline HbA1c by race was 54 to 57 mmol/mol (7.1%-7.4%). Mean 4-month reduction in placebo-adjusted HbA1c was greatest in East Asians (-6.6 mmol/mol [-0.60%] vs ≤6.0 mmol/mol [≤0.55%] in other groups), with significantly greater reduction vs the 2 largest groups (White Caucasians, Other Asians; P < .0001) after adjustment for covariates. After the first 4 months, East and Other Asians were more likely to initiate additional oral therapy (metformin and/or sulfonylureas) than insulin vs White Caucasians (P < .0001). Acarbose use increased in the Asian patients, but no glycaemic interaction with allocated study medication was observed (adjusted P = .12). CONCLUSIONS: The greatest initial reduction in HbA1c with sitagliptin in the TECOS population was in East Asians. No enhanced glycaemic effect was seen when sitagliptin was given with acarbose.

Pharmacoeconomic evaluation of glimepiride combined with other drugs in the treatment of diabetes.

The goal of diabetic drug treatment is to stabilize the blood sugar for a long time to close to the normal level, to correct the metabolic disorder and eliminate the symptoms. At present, glimepiride has become commonly used drugs for the treatment of diabetes with obesity. Compared with metformin, acarbose and rosiglitazone, glimepiride has different mechanisms of drug action, clinical combination showed synergistic hypoglycemic effect, good clinical curative effect. So, we use three treatments to study as group A (glimepiride and metformin); group B (glimepiride and acarbose); Group C (glimepiride and rosiglitazone). From the analysis of drug economics, glimepiride and metformin scheme is better, has the lowest cost per unit cost effect. From the comparison of scheme is efficient, the best curative effect is rosiglitazone plus glimepiride, effective rate as 96.7%. At the same time, the drug can be rationally used to reduce the occurrence of some drug-induced diseases and adverse drug reactions.

Oral anti-diabetic pharmacological therapies for the treatment of women with gestational diabetes.

BACKGROUND: Gestational diabetes mellitus (GDM) is a major public health issue with rates increasing globally. Gestational diabetes, glucose intolerance first recognised during pregnancy, usually resolves after birth and is associated with short- and long-term complications for the mother and her infant. Treatment options can include oral anti-diabetic pharmacological therapies. OBJECTIVES: To evaluate the effects of oral anti-diabetic pharmacological therapies for treating women with GDM. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register (14 May 2016), ClinicalTrials.gov, WHO ICTRP (14 May 2016) and reference lists of retrieved studies. SELECTION CRITERIA: We included published and unpublished randomised controlled trials assessing the effects of oral anti-diabetic pharmacological therapies for treating pregnant women with GDM. We included studies comparing oral anti-diabetic pharmacological therapies with 1) placebo/standard care, 2) another oral anti-diabetic pharmacological therapy, 3) combined oral anti-diabetic pharmacological therapies. Trials using insulin as the comparator were excluded as they are the subject of a separate Cochrane systematic review.Women with pre-existing type 1 or type 2 diabetes were excluded. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and trial quality. Two review authors independently extracted data and data were checked for accuracy. MAIN RESULTS: We included 11 studies (19 publications) (1487 women and their babies). Eight studies had data that could be included in meta-analyses. Studies were conducted in Brazil, India, Israel, UK, South Africa and USA. The studies varied in diagnostic criteria and treatment targets for glycaemic control for GDM. The overall risk of bias was 'unclear' due to inadequate reporting of methodology. Using GRADE the quality of the evidence ranged from moderate to very low quality. Evidence was downgraded for risk of bias (reporting bias, lack of blinding), inconsistency, indirectness, imprecision and for oral anti-diabetic therapy versus placebo for generalisability. Oral anti-diabetic pharmacological therapies versus placebo/standard careThere was no evidence of a difference between glibenclamide and placebo groups for hypertensive disorders of pregnancy (risk ratio (RR) 1.24, 95% confidence interval (CI) 0.81 to 1.90; one study, 375 women, very low-quality evidence), birth by caesarean section (RR 1.03, 95% CI 0.79 to 1.34; one study, 375 women, very low-quality evidence), perineal trauma (RR 0.98, 95% CI 0.06 to 15.62; one study, 375 women, very low-quality evidence) or induction of labour (RR 1.18, 95% CI 0.79 to 1.76; one study, 375 women; very low-quality evidence). No data were reported for development of type 2 diabetes or other pre-specified GRADE maternal outcomes (return to pre-pregnancy weight, postnatal depression). For the infant, there was no evidence of a difference in the risk of being born large-for-gestational age (LGA) between infants whose mothers had been treated with glibenclamide and those in the placebo group (RR 0.89, 95% CI 0.51 to 1.58; one study, 375, low-quality evidence). No data were reported for other infant primary or GRADE outcomes (perinatal mortality, death or serious morbidity composite, neurosensory disability in later childhood, neonatal hypoglycaemia, adiposity, diabetes). Metformin versus glibenclamideThere was no evidence of a difference between metformin- and glibenclamide-treated groups for the risk of hypertensive disorders of pregnancy (RR 0.70, 95% CI 0.38 to 1.30; three studies, 508 women, moderate-quality evidence), birth by caesarean section (average RR 1.20, 95% CI 1.20; 95% CI 0.83 to 1.72, four studies, 554 women, I2 = 61%, Tau2 = 0.07 low-quality evidence), induction of labour (0.81, 95% CI 0.61 to 1.07; one study, 159 women; low-quality evidence) or perineal trauma (RR 1.67, 95% CI 0.22 to 12.52; two studies, 158 women; low-quality evidence). No data were reported for development of type 2 diabetes or other pre-specified GRADE maternal outcomes (return to pre-pregnancy weight, postnatal depression). For the infant there was no evidence of a difference between the metformin- and glibenclamide-exposed groups for the risk of being born LGA (average RR 0.67, 95% CI 0.24 to 1.83; two studies, 246 infants, I2 = 54%, Tau2 = 0.30 low-quality evidence). Metformin was associated with a decrease in a death or serious morbidity composite (RR 0.54, 95% CI 0.31 to 0.94; one study, 159 infants, low-quality evidence). There was no clear difference between groups for neonatal hypoglycaemia (RR 0.86, 95% CI 0.42 to 1.77; four studies, 554 infants, low-quality evidence) or perinatal mortality (RR 0.92, 95% CI 0.06 to 14.55, two studies, 359 infants). No data were reported for neurosensory disability in later childhood or for adiposity or diabetes. Glibenclamide versus acarboseThere was no evidence of a difference between glibenclamide and acarbose from one study (43 women) for any of their maternal or infant primary outcomes (caesarean section, RR 0.95, 95% CI 0.53 to 1.70; low-quality evidence; perinatal mortality - no events; low-quality evidence; LGA , RR 2.38, 95% CI 0.54 to 10.46; low-quality evidence). There was no evidence of a difference between glibenclamide and acarbose for neonatal hypoglycaemia (RR 6.33, 95% CI 0.87 to 46.32; low-quality evidence). There were no data reported for other pre-specified GRADE or primary maternal outcomes (hypertensive disorders of pregnancy, development of type 2 diabetes, perineal trauma, return to pre-pregnancy weight, postnatal depression, induction of labour) or neonatal outcomes (death or serious morbidity composite, adiposity or diabetes). AUTHORS' CONCLUSIONS: There were insufficient data comparing oral anti-diabetic pharmacological therapies with placebo/standard care (lifestyle advice) to inform clinical practice. There was insufficient high-quality evidence to be able to draw any meaningful conclusions as to the benefits of one oral anti-diabetic pharmacological therapy over another due to limited reporting of data for the primary and secondary outcomes in this review. Short- and long-term clinical outcomes for this review were inadequately reported or not reported. Current choice of oral anti-diabetic pharmacological therapy appears to be based on clinical preference, availability and national clinical practice guidelines.The benefits and potential harms of one oral anti-diabetic pharmacological therapy compared with another, or compared with placebo/standard care remains unclear and requires further research. Future trials should attempt to report on the core outcomes suggested in this review, in particular long-term outcomes for the woman and the infant that have been poorly reported to date, women's experiences and cost benefit.

Rumen microbial and fermentation characteristics are affected differently by acarbose addition during two nutritional types of simulated severe subacute ruminal acidosis in vitro.

Little information is available on whether or not the effect of an alpha-glucosidase inhibitor on the prevention of ruminal acidosis is influenced by the type of diet during ruminant feeding. This study was conducted to explore the effect of acarbose addition on the prevention of severe subacute ruminal acidosis induced by either cracked wheat or beet pulp in vitro. Cracked wheat and beet pulp were fermented in vitro by rumen microorganisms obtained from three dairy cows. When cracked wheat was used as the substrate and fermented for 24 h, compared with the control, acarbose addition decreased the concentrations of acetate, propionate, butyrate, total volatile fatty acids, and lactate (P < 0.05), while linearly increased the ratio of acetate to propionate, pH value, and the ammonia-nitrogen level (P < 0.05). Applying Illumina MiSeq sequencing of a fragment of the 16S rRNA gene revealed that the relative abundance of Firmicutes and Bacteroidetes as well as the ACE (abundance-based coverage estimator) value, Chao 1 value, and Shannon index increased significantly (P < 0.05), while there was a significant reduction (P < 0.05) in the relative abundance of Tenericutes as well as Proteobacteria after adding acarbose compared to the control. On the other hand, when beet pulp was used as the substrate, acarbose addition had no significant effects (P > 0.05) on the fermentation parameters and the Chao 1 value, the Shannon index, and the proportion of Firmicutes and Bacteroidetes. In general, these findings indicate that acarbose had more effects on ruminal fermentation when wheat was used as the substrate, whereas it exhibited little effect on ruminal fermentation when beet pulp was used as the substrate.

[Hypoglycemia due to antibodies to exogenous insulin in a patient with type 2 diabetes ­ a case report of treatment with new generation oral hypoglycemic agents].

Hypoglycemic syndromes associated with immune reactions against insulin are rare phenomena described predominantly in Asians. Steroid therapy, immunosuppression or plasmapheresis is often required. Case report: A 73-year-old White woman with a 20-year history of type 2 diabetes was admitted to hospital due to recurrent incidents of hypoglycemia that started several months after insulin initiation (lispro 75/25) and increased in severity over the next 5 years. They were accompanied by postprandial hyperglycemia up to 25 mmol/l. The patient's glycated hemoglobin (HbA1c) was 70 mmol/ mol (8.6%). During hypoglycemic episodes recorded serum C-peptide was 0.57-0.73 nmol/l (1.7-2.2 ng/ml), while insulin concentration exceeded 7000 pmol/l (1000 mIU/l). Surreptitious insulin administration was ruled out as was, based on diagnostic imaging, the presence of an insulin secreting tumor. Anti-insulin antibody (AIA) level measured by 125I-insulin binding method was 92.5% (normal < 8.2%). Hypoglycemic episodes occurred for four days after discontinuation of insulin therapy and then resolved completely. Good glycemic control was maintained with metformin, acarbose and dapagliflozin. Three months later dapagliflozin was replaced with vildagliptine due to poor tolerance of a SGLT-2 inhibitor. Patient's HbA1c was 54 mmol/mol (7.1%), total fasting insulin level 2577 pmol/l and AIA binding 85.9%. Over the next year the patient has not experienced hypoglycemia and maintained good glycemic control, as HbA1c level was 53 mmol/l (7.0%) and AIA binding 39.5%. Conclusions: In this rare case of a patient with diabetes and hypoglycemic syndrome related to AIA, we achieved a rapid and stable remission of hypoglycemia without immunosuppression. Good glycemic control, despite 20-year history of diabetes was achieved with oral hypoglycemic agents.

Using oral agents to manage gestational diabetes: what have we learned?

Insulin has been the mainstay of treatment of diabetes during pregnancy for decades. Although glyburide and metformin are classified as category B during pregnancy, recent research has suggested that these oral agents alone or in conjunction with insulin may be safe for the treatment of gestational diabetes (GDM). This paper summarizes the data on the use of glyburide and metformin for treatment of GDM.

Investigation of bioequivalence of a new fixed-dose combination of acarbose and metformin with the corresponding loose combination as well as the drug-drug interaction potential between both drugs in healthy adult male subjects.

WHAT IS KNOWN AND OBJECTIVE: Both metformin and acarbose are recommended monotherapy and add-on therapy in type 2 diabetes mellitus (T2DM). A fixed-dose combination (FDC) of acarbose and metformin has been developed to reduce pill burden and potentially improve compliance. The current study investigated the bioequivalence of the acarbose/metformin FDC compared with the individual agents administered simultaneously (loose combination). Secondary endpoints were the safety and tolerability of the FDC and the potential for drug-drug interactions between acarbose and metformin. METHODS: A single-centre, randomized, open-label, four-period crossover study was conducted in healthy male Korean subjects aged 18-45 years. Following one-period balanced Williams design, participants were randomized to receive four single oral treatments on different study days separated by ≥7 days' washout. Treatments were as follows: (i) acarbose/metformin 50/500 mg FDC (test); (ii) acarbose 50 mg and metformin 500 mg as loose combination (reference); (iii) acarbose 50 mg; and (iv) metformin 500 mg. Serial blood samples were taken for glucose and insulin levels for 4 h after a sucrose load on the day before and day of study drug administration. Additionally, serial blood samples were taken for analysis of metformin levels for 24 h after each drug containing metformin. The area under the curve for 4 h post-test (AUC0-4 h ) and the maximal serum concentration (Cmax ) of plasma glucose and serum insulin were primary pharmacodynamic (PD) parameters, and Cmax , AUC0-last and AUC for metformin levels were primary pharmacokinetic (PK) parameters. The bioequivalence of the FDC to the loose combination was considered established if the 90% confidence intervals (CIs) of the baseline-adjusted PD parameter ratios (test vs. reference) for plasma glucose and the PK parameter ratios for metformin fell completely within current acceptance limits (0·8-1·25). RESULTS AND DISCUSSION: Thirty-three of 40 randomized subjects completed the study; five withdrew consent and two discontinued because of adverse events (AEs). The 24-h plasma concentration-time curves of metformin and the 4-h plasma glucose-time curves after acarbose/metformin FDC (test) and acarbose + metformin loose combination (reference) were almost superimposable. The geometric least squares (LS) mean of the RatioAUC and RatioCmax for plasma glucose after the FDC vs. loose combination, and the LS mean of the ratios in metformin AUC, AUC0-last and Cmax were close to unity, and the 90% CI of all these parameters fell within the predefined equivalence range of 0·8-1·25, confirming bioequivalence. The metformin AUC was reduced by 26% and Cmax by 34% after acarbose + metformin compared with metformin alone. Eight subjects (20·0%) reported AEs, but all were mild, and most were gastrointestinal, as expected for these agents. The incidence of AEs was not higher with the combinations vs. monotherapy. WHAT IS NEW AND CONCLUSION: These data demonstrate that the acarbose/metformin FDC is bioequivalent to the loose combination of these agents. Although acarbose slightly reduced the bioavailability of metformin, the accumulated evidence of the efficacy of this combination implies that this is clinically irrelevant. The observed AE profile was consistent with the established knowledge on the safety of the two drugs.

Alpha glucosidase inhibitors.

Alpha glucosidase inhibitors (AGIs) are a unique class of anti-diabetic drugs. Derived from bacteria, these oral drugs are enzyme inhibitors which do not have a pancreato -centred mechanism of action. Working to delay carbohydrate absorption in the gastrointestinal tract, they control postprandial hyperglycaemia and provide unquestioned cardiovascular benefit. Specially suited for a traditional Pakistani carbohydrate-rich diet, AGIs have been termed the 'untapped diamonds' of diabetology. The use of these oral antidiabetic drugs (OADs) that target pathophysiology in the early stages of type 2 diabetes, notably to reduce postprandial hyperglycaemia and hyperinsulinaemia will inevitably increase with time. This review describes the history of their development, mechanism of action, basic and clinical pharmacology, and suggests practical, evidence-based guidance for their optimal use.

Pharmacodynamic bioequivalence testing.

WHAT IS KNOWN AND OBJECTIVE: The assessment of bioequivalence of drugs intended for local action/targeted delivery and with poor systemic absorption presents unique challenges. Approaches such as pharmacodynamic (PD) bioequivalence testing have been proposed as alternatives to pharmacokinetic (PK) bioequivalence studies. Our objective is to comment on when PD bioequivalence testing might be considered appropriate and whether the acceptance criteria for bioequivalence could be adjusted based on observed variability in PD response. COMMENT: Pharmacokinetic bioequivalence studies are generally conducted to evaluate the rate and extent of drug absorption of a test drug as compared to a reference drug. However, this may not be appropriate for locally acting drugs, when the plasma drug concentrations, if measurable, are not correlated with the clinical therapeutic effect. Systemic absorption may in fact be undesirable for such drugs. The US Food and Drug Administration (FDA) recommends alternative approaches for evaluating the bioequivalence of acarbose, including a bioequivalence study with a PD endpoint. For the evaluation of therapeutic equivalence of highly variable drugs, adjusting the acceptance interval for the PK parameters has been discussed by the FDA and the European Medicines Agency (EMEA). However, it is still not clear whether the newly proposed methodology is applicable to PD bioequivalence testing. WHAT IS NEW AND CONCLUSION: Although no consensus has been reached on the criteria for PD bioequivalence testing, various approaches are currently being investigated. Further studies should be performed to assess whether an adjustment of the acceptance intervals is appropriate based on the within-subject variability of PD responses. This may potentially minimize the unnecessary exposure of a large number of subjects to the test drugs.

Pharmacodynamic comparison of two formulations of Acarbose 100-mg tablets.

WHAT IS KNOWN AND OBJECTIVE: Acarbose, an α-glycosidase inhibitor, is used to treat diabetic patients. Pharmacokinetic evaluation of acarbose is difficult because <2% is absorbed systemically. The current investigation evaluated the bioequivalence of two formulations of acarbose through pharmacodynamic comparison. METHODS: This investigation consisted of a pilot study and a main study. The pilot study had an open, single-dose, single-sequence design. Subjects received placebo and then two tablets of reference formulation (Glucobay(®) 100 mg tablet; Bayer Healthcare) on two consecutive days with sucrose. The main study was an open, randomized, two-period, two-sequence crossover study. Subjects randomly received placebo and two tablets of either test formulation (generic acarbose 100-mg tablet) or reference formulation with sucrose on two consecutive days in the first period. In the second period, placebo and alternative formulation were administered. Serial blood samples for pharmacodynamic assessment were taken after each administration. The maximum serum glucose concentration (G(max)) and the area under the serum glucose concentration-time profile (AUC(gluc)) were determined and compared. RESULTS AND DISCUSSION: Five subjects completed the pilot study. The AUC(gluc) from dosing until 1 h post-dose (AUC(gluc,1 h)) was significantly different between the placebo and acarbose. A total of 33 subjects completed the main study. The mean differences in G(max) (ΔG(max)) and AUC(gluc,1 h) (ΔAUC(gluc,1 h)) for the reference formulation compared with placebo were 22·0 ± 18·3 mg/dL and 928·2 ± 756·0 mg min/dL, respectively. The corresponding values for the test formulation were 23·3 ± 21·2 mg/dL and 923·0 ± 991·4 0 mg min/dL, respectively. The geometric mean ratios (GMRs) of the test formulation to the reference formulation for ΔG(max) and ΔAUC(gluc, 1 h) were 1·06 and 1·00, respectively, and the 90% confidence intervals (CIs) corresponding values were 0·79-1·39 and 0·64-1·36, respectively. WHAT IS NEW AND CONCLUSION: The 90% CIs of GMRs for the pharmacodynamic parameters chosen for bioequivalence evaluation of two formulations of acarbose did not meet the commonly accepted regulatory criteria for bioequivalence (0·80-1·25).

A novel synergistic galactomannan-based unit dosage form for sustained release of acarbose.

In the current study, the potential of a novel combination of a galactomannan with acarbose (100 mg) was evaluated for attaining a desired hypoglycaemic effect over a prolonged period of time. Three major antidiabetic galactomannans viz., fenugreek gum, Boswellia gum, and locust bean gum were selected in order to achieve a synergistic effect in the treatment along with retardation in drug release. In vitro studies indicated that batches containing various proportions of fenugreek gum (AF40-60) were able to control drug release for a longer duration of approximately 10-12 h. In contrast, the matrices prepared using Boswellia and locust bean gum were able to sustain the release for relatively shorter durations. Drug release mainly followed first-order release kinetics owing to the highly soluble nature of the drug. In vivo study depicted a significant reduction (p < 0.001) in the postprandial blood glucose and triglyceride levels in the diabetic rats on treatment with formulation AF40. Thus, the developed system provides a better control of the postprandial glycaemic levels and it also obviates the need of conventional multiple dosing of acarbose. Furthermore, it also reduces the occurrence of side effects like diarrhea and loss of appetite.

Safety and efficacy of high-dose acarbose treatment for dumping syndrome.

Dumping syndrome (DS) is a complication of Nissen fundoplication. Dietary strategies can ameliorate symptoms, but this approach is not always foolproof. Limited evidence reports the efficacy of acarbose for children who are unresponsive to feeding manipulations. We report 8 patients with DS aged between 7 and 24 months. In 4 of 8 nutritional strategies failed, and acarbose treatment was started. The initial dose was 25 mg for meals, and increased until postprandial glucose was stable. In 3 of 4 children the final dose was higher than previously reported, without adverse effects. Acarbose is useful to treat DS in cases of failure of dietary strategies.

Evaluation of the Bioequivalence of Acarbose in Healthy Chinese People.

The purpose of this study was to determine whether the reference formulation and test formulation of acarbose are bioequivalent among healthy Chinese subjects based on evaluation of the pharmacodynamic end point. Two clinical trials with acarbose were conducted: study A, a pilot study (n = 12; 50 and 100 mg), and study B, a pivotal study (n = 60; 50 mg). In study A, there was a dose-dependent relationship between 50 mg acarbose and 100 mg acarbose and a significant difference compared with sucrose alone. In study B, after logarithmic conversion, a linear mixed-effects model was used to analyze the maximum serum glucose value and area under the serum glucose-time curve from 0 to 2 hours. The geometric mean ratios (test formulation/reference formulation) were 92.68% and 95.70%, with 90% confidence intervals of 84.08%-102.17% and 84.21%-108.76%, respectively, falling between 80.00% and 125.00%. According to the geometric least-squares mean, the test formulation (or reference formulation) was statistically significantly different as a single sucrose (P < .001). The effective dose of acarbose in healthy Chinese volunteers was 50 mg. The reference and test formulations were bioequivalent.

The effects of acarbose therapy on reductions of myocardial infarction and all-cause death in T2DM during 10-year multifactorial interventions (The Beijing Community Diabetes Study 24).

To investigate the potential benefits of acarbose therapy on cardiovascular events (CVD) in Type 2 diabetes (T2DM) in an urban community over 10-year follow-up. The study population of Beijing Community Diabetes Study (BCDS) were type 2 diabetes (T2DM) living in 21 communities in Beijing. All patients received comprehensive intervention in accordance with the Chinese guidelines for the prevention and treatment of diabetes. Professors in endocrinology from top tier hospitals regularly visited the communities for consultations, which was a feature of this study. A total of 1797 T2DM in BCDS study had complete screening data, including blood glucose, blood pressure, lipid profiles and acarbose continuous therapy. After 10-year follow-up, the risks of CVD outcomes were assessed according to whether patients had received acarbose therapy or not. All patients were followed-up to assess the long-term effects of the multifactorial interventions. At baseline, compared with the acarbose therapy free in T2DM, there was no significant difference in achieving the joint target control in patients with acarbose therapy. From the beginning of 8th year follow-up, the joint target control rate in patients with acarbose therapy was significantly higher than that of acarbose therapy free. During the 10-year follow-up, a total of 446 endpoint events occurred, including all-cause death, cardiovascular events, cerebrovascular events. The incidences of myocardial infarction (from the 4th year of follow-up) and all-cause death (from the 2nd year of follow-up) in patients who received acarbose therapy were significantly lower than that of acarbose therapy free respectively. In Cox multivariate analyses, there were significant differences in incidences of myocardial infarction and all-cause death between afore two groups during the 10-year follow-up, and the adjusted HRs were 0.50 and 0.52, respectively. After multifactorial interventions, T2DM with acarbose therapy revealed significant reductions of myocardial infarction and all-cause death. The long-term effects of with acarbose therapy on improving joint target control might be one of the main reasons of myocardial infarction and all-cause death reduction.Trial Registration: ChiCTR-TRC-13003978, ChiCTR-OOC-15006090.