Voglibose administration before the evening meal improves nocturnal hypoglycemia in insulin-dependent diabetic patients with intensive insulin therapy

Trends in Antidiabetic Drug Discovery: FDA Approved Drugs, New Drugs in Clinical Trials and Global Sales

Type 2 diabetes mellitus (T2DM) continues to be a substantial medical problem due to its increasing global prevalence and because chronic hyperglycemic states are closely linked with obesity, liver disease and several cardiovascular diseases. Since the early discovery of insulin, numerous antihyperglycemic drug therapies to treat diabetes have been approved, and also discontinued, by the United States Food and Drug Administration (FDA). To provide an up-to-date account of the current trends of antidiabetic pharmaceuticals, this review offers a comprehensive analysis of the main classes of antihyperglycemic compounds and their mechanisms: insulin types, biguanides, sulfonylureas, meglitinides (glinides), alpha-glucosidase inhibitors (AGIs), thiazolidinediones (TZD), incretin-dependent therapies, sodium-glucose cotransporter type 2 (SGLT2) inhibitors and combinations thereof. The number of therapeutic alternatives to treat T2DM are increasing and now there are nearly 60 drugs approved by the FDA. Beyond this there are nearly 100 additional antidiabetic agents being evaluated in clinical trials. In addition to the standard treatments of insulin therapy and metformin, there are new drug combinations, e.g., containing metformin, SGLT2 inhibitors and dipeptidyl peptidase-4 (DPP4) inhibitors, that have gained substantial use during the last decade. Furthermore, there are several interesting alternatives, such as lobeglitazone, efpeglenatide and tirzepatide, in ongoing clinical trials. Modern drugs, such as glucagon-like peptide-1 (GLP-1) receptor agonists, DPP4 inhibitors and SGLT2 inhibitors have gained popularity on the pharmaceutical market, while less expensive over the counter alternatives are increasing in developing economies. The large heterogeneity of T2DM is also creating a push towards more personalized and accessible treatments. We describe several interesting alternatives in ongoing clinical trials, which may help to achieve this in the near future.

Synthesis of 2-(4-hydroxyphenyl)ethyl 3,4,5-Trihydroxybenzoate and Its Inhibitory Effect on Sucrase and Maltase

We report on the synthesis of an active component, 2-(4-hydroxyphenyl)ethyl 3,4,5-trihydroxybenzoate (HETB), from Rhodiola crenulata. Subsequent analysis revealed that HETB exhibits α-glucosidase inhibitory activities on maltase and sucrase, with potency exceeding that of the known α-glucosidase inhibitors (voglibose and acarbose). An inhibition kinetics study revealed that HETB, acarbose, and voglibose bind to maltase and sucrase, and HETB was shown to be a strong competitive inhibitor of maltase and sucrase. In a molecular docking study based on the crystal structure of α-glucosidase from Saccharomyces cerevisiae, we revealed the HETB binding in the active site of maltase via hydrogen-bond interactions with five amino acid residues: Ser 240, Asp 242, Glu 277, Arg 315, and Asn 350. For HETB docked to the sucrase active site, seven hydrogen bonds (with Asn 114, Glu 148, Gln 201, Asn 228, Gln 381, Ile 383, and Ser 412) were shown.

Retrospective comparison of voglibose or acarbose as an add-on therapy to sulfonylureas in Western Indian patients with uncontrolled overweight/obese type 2 diabetes

AIM

The study was aimed to investigate the effect of voglibose or acarbose as an add-on treatment in overweight/obese type 2 diabetes (T2DM) patients who are uncontrolled with metformin and sulfonylureas (SUs) in Western part of India.

PARTICIPANTS AND METHODS

A retrospective study included 77 participants (BMI≥25kg/m(2); HbA1c level>8% and<9.5%) with overweight/obese T2DM. These participants were treated with either voglibose or acarbose. Glycemic parameters (fasting blood glucose and glycated hemoglobin [HbA1c]), bodyweight, BMI and lipid parameters were evaluated at baseline, 3-month, 6-month and 9-month of treatment. Adverse events were also captured at respective time points.

RESULTS

Voglibose showed significant reduction in HbA1c and bodyweight with short duration of treatment (6 months; P<0.05 and 9 months; P<0.01) whereas acarbose showed significant reduction with longer duration of treatment (9 months; P<0.05) when compared with baseline. Moreover, both treatment groups were reported with reduction in BMI. Further, significant improvement in lipid parameters except LDL and HDL were observed in both treatment groups when compared with baseline. None of participant was discontinued due to side effects of the treatment. In addition, the frequency of hypoglycemia was decreased in both treatment groups.

CONCLUSION

Voglibose or acarbose as an add-on treatment with metformin and sulfonylureas in uncontrolled obese/overweight T2DM provides desired glycemic control, reduces bodyweight and improves lipid parameters with good tolerability profile.

Therapeutic potential of α-glucosidase inhibitors in type 2 diabetes mellitus: an evidence-based review

INTRODUCTION

Postprandial hyperglycemia (PPHG) contributes to micro- and macro-vascular complications more than fasting hyperglycemia in patients with type 2 diabetes mellitus. Due to the traditional carbohydrate-rich diet, Asians, particularly Indians and Chinese need agents to control the higher risk of uncontrolled PPHG. Targeting PPHG with α-glucosidase inhibitors (AGIs), either alone or in combination with other oral hypoglycemic agents and insulin, provide overall glycemic control with transient mild gastrointestinal disorders. Treatment with AGIs, especially acarbose, has also shown to provide beneficial effects on lipid levels, blood pressure, coagulation factors, carotid intima-media thickness and endothelial dysfunction. New insights of acarbose therapy obtained like increased activity of gut hormones and improved gut microbiota may explain the benefits on weight, whereas increased production of H2 may explains its cardiovascular benefits to some extent.

AREAS COVERED

A systematic search strategy was developed to identify randomized controlled trials in MEDLINE, PubMed, EMBASE and ongoing trials databases.

EXPERT OPINION

AGIs as a class and acarbose in particular, are most useful in combatting PPHG and glucose variability across the spectrum of diabetes therapy, particularly in Asian patients. Together with their effects on incretin hormones and gut-microbiota AGIs can be considered beyond glycemic control as 'cardio-protective agents.'

Pharmacokinetic study of metformin to compare voglibose/metformin fixed-dose combination with coadministered voglibose and metformin

The aim of this study was to compare the pharmacokinetic characteristics of metformin between a fixed-dose combination (FDC) of voglibose/metformin and co-administered individual voglibose and metformin tablets in healthy Korean volunteers under fasting conditions. A randomized, open-label, single-dose, two-treatment, two-way crossover study with a 7-day wash-out period was conducted. Plasma samples were collected for up to 24 hours and were analyzed for metformin using a validated liquid chromatography tandem mass-spectrometry (LC/MS). A non-compartmental method was used to calculate the pharmacokinetic parameters. Vital signs and adverse events were monitored, and physical examinations and laboratory tests were conducted to evaluate safety. In total, 28 subjects completed the study. The geometric mean ratio (GMR) and the 90% confidence interval (CIs) of C_max and AUC_0–t of metformin were 102.4 (94.5 – 111.0) and 107.1 (100.1 – 114.7), respectively. In total, 7 adverse drug reactions occurred in 4 subjects during the study; of these, 3 cases were from 3 subjects in the test treatment group, and 4 cases were from 3 subjects in the reference treatment group. All adverse drug reactions had been reported previously, and all subjects recovered fully without any sequelae. In conclusion, the pharmacokinetic profiles of metformin in two different study treatments, a voglibose/metformin FDC vs. the coadministration of the individual formulations, met the regulatory criteria for bioequivalence in healthy Korean subjects under fasting conditions. There was no significant difference in safety profiles between the two treatments.

Late postprandial hypoglycemia due to bioactive insulin dissociation from autoantibody leading to unconsciousness in a patient with insulin autoimmune syndrome

We report here the case of an 83-year-old man who was treated for unconsciousness and hypoglycemia (39 mg/dL) accompanied by marked elevation of serum immunoreactive insulin (IRI) (4,760 µIU/mL). We diagnosed his condition as insulin autoimmune syndrome (IAS, Hirata disease) because of a high insulin autoantibody (IAA) titer (>90%: bound/total) and no history of exogenous insulin administration. Reactive hypoglycemia occurred due to immediate association followed by dissociation between insulin and insulin autoantibodies after glucose or food intake. An α-glucosidase inhibitor in combination with frequent small meals reduced the postprandial hyperglycemia (glucose spike) and ameliorated the reactive hypoglycemia.

Sleep and the response to hypoglycaemia

Undetected nocturnal hypoglycaemia frequently occurs in patients with diabetes, having a negative influence on well-being, counterregulation against and awareness of subsequent hypoglycaemia, and even causing sudden death in some cases most likely by inducing cardiac arrhythmia. Sleep markedly weakens the neuroendocrine defence mechanism against hypoglycaemia by shifting the glycaemic threshold for counterregulatory activation to lower levels. While hypoglycaemia triggers awakening in healthy subjects, patients with type 1 diabetes frequently fail to awake in the presence of low plasma glucose levels. Little is known about the frequency of and responses to nocturnal hypoglycaemia in patients with type 2 diabetes. Unfortunately, effective strategies to prevent or even safely detect nocturnal hypoglycaemia are still lacking. Taken together, hypoglycaemia occurring during sleep presents a major, often neglected problem in the management of diabetic patients. Different aspects of this phenomenon such as responses to and consequences of nocturnal hypoglycaemia as well as strategies for its prevention are highlighted in this review.

Nocturnal hypoglycemia: clinical manifestations and therapeutic strategies toward prevention

OBJECTIVE

To review the features of nocturnal hypoglycemia and various preventive strategies.

METHODS

We discuss the physiologic changes, the potential precipitating factors, the immediate and long-term effects, and the currently available options for treatment of nocturnal hypoglycemia in patients with diabetes.

RESULTS

Nocturnal hypoglycemia is common in patients with type 1 diabetes and is usually asymptomatic. Nocturnal hyperinsulinemia frequently occurs with insulin therapy, and although blood glucose levels are often low during sleep, they are seldom measured routinely. Almost 50% of all episodes of severe hypoglycemia occur at night during sleep. Such episodes can cause convulsions and coma and have been implicated as a precipitating factor in cardiac arrhythmias resulting in sudden death--the "dead-in-bed syndrome." Nocturnal hypoglycemia seems to have no immediate detrimental effect on cognitive function; however, on the following day, mood and well-being may be adversely affected. Recurrent exposure to nocturnal hypoglycemia may impair cognitive function; other substantial long-term morbidity includes the development of acquired hypoglycemia syndromes, such as impaired awareness of hypoglycemia, through the putative effect of unsuspected recurrent episodes of nocturnal hypoglycemia.

CONCLUSION

In efforts to decrease the risk of nocturnal hypoglycemic episodes, various strategies can be used to minimize the nocturnal hyperinsulinemia that is associated with many insulin replacement regimens. Regular blood glucose monitoring (particularly at bedtime), the ingestion of appropriate bedtime snacks, and the utilization of short- and long-acting insulin analogues may all help to prevent or minimize the frequency of nocturnal hypoglycemia.

Long-term therapeutic effects of voglibose, a potent intestinal alpha-glucosidase inhibitor, in spontaneous diabetic GK rats

The effect of long-term (6 months) administration of voglibose in a dietary mixture (10 ppm) on intestinal disaccharidase activity was examined in non obese type 2 diabetes model Goto-Kakizaki (GK) rats. The postprandial blood glucose level in voglibose-treated GK rats was significantly lower than in untreated GK rats (190+/-19 vs. 250+/-25 mg/dl, P<0.01; 1 h, 212+/-23 vs. 256+/-20, P<0.05; 2 h), and the activities of maltase, sucrase, and isomaltase remained significantly lower throughout the 6 months of voglibose treatment. The expressions of protein and mRNA of sucrase-isomaltase (SI) complex were significantly higher in voglibose-treated GK rats. Voglibose administration then was stopped after 6 months of treatment. The mRNA level and protein level of the SI complex became normalized during the interruption of drug administration, and disaccharidase activities increased almost to the level of the untreated group 1 month after treatment was stopped. After 1 day of re-administration of the drug, however, disaccharidase activities again became significantly inhibited. These results indicate that voglibose may improve glucose tolerance since it inhibits activities of disaccharidases in spite of increasing the expression of them on intestine, furthermore voglibose may be reversible and reproducible through interruption and re-administration.

Inhibitory effect of voglibose and gymnemic acid on maltose absorption in vivo

AIM: To determine whether diabetic care can be improved by combination of voglibose and gymnemic acid (GA), we compared the combinative and individual effects of voglibose and GA on maltose absorption in small intestine.

METHODS: The small intestine 30 cm long from 2 cm caudal ward Treitz’s ligament of Wistar rat was used as an in situ loop, which was randomly perfused in recircular mode with maltose (10 mmol/L) with or without different dosages of voglibose and/or GA for 1 h. To compare the time course, perfusion of 10 mmol/L maltose was repeated four times. Each time continued for 1 h and separated by 30 min rinse. In the first time, lower dosages of GA (0.5 g/L) and/or voglibose (2 μmol/L) were contained except control.

RESULTS: Absorptive rate of maltose was the lowest in combinative group (P < 0.05, ANOVA), for example, the inhibition rate was about 37% during the first hour when0.5 g/L-GA and 2 μmol/L voglibose with 10 mmol/L maltose were perfused in the loop. The onset time was shortened to 30 min and the effective duration was prolonged to 4 h with the combination; therefore the total amount of maltose absorption during the effective duration was inhibited more significantly than that in the individual administration (P < 0.05, U test of Mann Whitney). The effect of GA on absorptive barriers of the intestine played an important role in the combinative effects.

CONCLUSION: There are augmented effects of voglibose and GA. The management of diabetes mellitus can be improved by employing the combination.