Glyset
Glyset - General Information
Glyset is an oral anti-diabetic drug that acts by inhibiting the ability of the patient to breakdown complex carbohydrates into glucose. It is primarily used in diabetes mellitus type 2 for establishing greater glycemic control by preventing the digestion of carbohydrates (such as disaccharides, oligosaccharides, and polysaccharides) into monosaccharides which can be absorbed by the body.
Glyset inhibits glycoside hydrolase enzymes called alpha-glucosidases. Since miglitol works by preventing digestion of carbohydrates, it lowers the degree of postprandial hyperglycemia. It must be taken at the start of main meals to have maximal effect. Its effect will depend on the amount of non-monosaccharide carbohydrates in a person's diet.
In contrast to acarbose (another alpha-glucosidase inhibitor), miglitol is systemically absorbed; however, it is not metabolized and is excreted by the kidneys.
Pharmacology of Glyset
Glyset, an oral alpha-glucosidase inhibitor, is a desoxynojirimycin derivative that delays the digestion of ingested carbohydrates, thereby resulting in a smaller rise in blood glucose concentration following meals. As a consequence of plasma glucose reduction, miglitol reduce levels of glycosylated hemoglobin in patients with Type II (non-insulin-dependent) diabetes mellitus. Systemic nonenzymatic protein glycosylation, as reflected by levels of glycosylated hemoglobin, is a function of average blood glucose concentration over time. Because its mechanism of action is different, the effect of miglitol to enhance glycemic control is additive to that of sulfonylureas when used in combination. In addition, miglitol diminishes the insulinotropic and weight-increasing effects of sulfonylureas. Glyset has minor inhibitory activity against lactase and consequently, at the recommended doses, would not be expected to induce lactose intolerance.
Glyset for patients
The following information should be provided to patients:
- GLYSET should be taken orally three times a day at the start (with the first bite) of each main meal. It is important to continue to adhere to dietary instructions, a regular exercise program, and regular testing of urine and/or blood glucose.
- GLYSET itself does not cause hypoglycemia even when administered to patients in the fasted state. Sulfonylurea drugs and insulin, however, can lower blood sugar levels enough to cause symptoms or sometimes life-threatening hypoglycemia. Because GLYSET given in combination with a sulfonyl-urea or insulin will cause a further lowering of blood sugar, it may increase the hypoglycemic potential of these agents. The risk of hypoglycemia, its symptoms and treatment, and conditions that predispose to its development should be well understood by patients and responsible family members. Because GLYSET prevents the breakdown of table sugar, a source of glucose (dextrose, D-glucose) should be readily available to treat symptoms of low blood sugar when taking GLYSET in combination with a sulfonyl-urea or insulin.
- If side effects occur with GLYSET, they usually develop during the first few weeks of therapy. They are most commonly mild-to-moderate dose-related gastrointestinal effects, such as flatulence, soft stools, diarrhea, or abdominal discomfort, and they generally diminish in frequency and intensity with time. Discontinuation of drug usually results in rapid resolution of these gastrointestinal symptoms.
Glyset Interactions
Several studies investigated the possible interaction between miglitol and glyburide. In six healthy volunteers given a single dose of 5-mg glyburide on a background of 6 days treatment with miglitol (50 mg 3 times daily for 4 days followed by 100 mg 3 times daily for 2 days) or placebo, the mean C max and AUC values for glyburide were 17% and 25% lower, respectively, when glyburide was given with miglitol. In a study in diabetic patients in which the effects of adding miglitol 100 mg 3 times daily x 7 days or placebo to a background regimen of 3.5 mg glyburide daily were investigated, the mean AUC value for glyburide was 18% lower in the group treated with miglitol, although this difference was not statistically significant. Further information on a potential interaction with glyburide was obtained from one of the large U.S. clinical trials (Study 7) in which patients were dosed with either miglitol or placebo on a background of glyburide 10 mg twice daily. At the 6-month and 1-year clinic visits, patients taking concomitant miglitol 100 mg 3 times daily exhibited mean C max values for glyburide that were 16% and 8% lower, respectively, compared to patients taking glyburide alone. However, these differences were not statistically significant. Thus, although there was a trend toward lower AUC and C max values for glyburide when co-administered with GLYSET, no definitive statement regarding a potential interaction can be made based on the foregoing three studies.
The effect of miglitol (100 mg 3 times daily x 7 days) on the pharmacokinetics of a single 1000-mg dose of metformin was investigated in healthy volunteers. Mean AUC and C max values for metformin were 12% to 13% lower when the volunteers were given miglitol as compared with placebo, but this difference was not statistically significant.
In a healthy volunteer study, co-administration of either 50 mg or 100 mg miglitol 3 times daily together with digoxin reduced the average plasma concentrations of digoxin by 19% and 28%, respectively. However, in diabetic patients under treatment with digoxin, plasma digoxin concentrations were not altered by co-administration of miglitol 100 mg 3 times daily x 14 days.
Other healthy volunteer studies have demonstrated that miglitol may significantly reduce the bioavailability of ranitidine and propranolol by 60% and 40%, respectively. No effect of miglitol was observed on the pharmacokinetics or pharmacodynamics of either warfarin or nifedipine.
Intestinal adsorbents (e.g., charcoal) and digestive enzyme preparations containing carbohydrate splitting enzymes (e.g., amylase, pancreatin) may reduce the effect of GLYSET and should not be taken concomitantly.
In 12 healthy males, concomitantly administered antacid did not influence the pharmacokinetics of miglitol.
Glyset Contraindications
GLYSET Tablets are contraindicated in patients with:
- Diabetic ketoacidosis
- Inflammatory bowel disease, colonic ulceration, or partial intestinal obstruction, and in patients predisposed to intestinal obstruction
- Chronic intestinal diseases associated with marked disorders of digestion or absorption, or with conditions that may deteriorate as a result of increased gas formation in the intestine
- Hypersensitivity to the drug or any of its components.
Additional information about Glyset
Glyset Indication: For use as an adjunct to diet to improve glycemic control in patients with non-insulin-dependent diabetes mellitus (NIDDM) whose hyperglycemia cannot be managed with diet alone.
Mechanism Of Action: In contrast to sulfonylureas, miglitol does not enhance insulin secretion. The antihyperglycemic action of miglitol results from a reversible inhibition of membrane-bound intestinal a-glucoside hydrolase enzymes. Membrane-bound intestinal a-glucosidases hydrolyze oligosaccharides and disaccharides to glucose and other monosaccharides in the brush border of the small intestine. In diabetic patients, this enzyme inhibition results in delayed glucose absorption and lowering of postprandial hyperglycemia.
Drug Interactions: Glucosamine Possible hyperglycemia
Food Interactions: Not Available
Generic Name: Miglitol
Synonyms: Not Available
Drug Category: Anti-Bacterial Agents; Enzyme Inhibitors; Hypoglycemic Agents
Drug Type: Small Molecule; Approved
Other Brand Names containing Miglitol: Glyset;
Absorption: Absorption of miglitol is saturable at high doses with 25 mg being completely absorbed while a 100-mg dose is only 50-70% absorbed. No evidence exists to show that systemic absorption of miglitol adds to its therapeutic effect.
Toxicity (Overdose): Unlike sulfonylureas or insulin, an overdose will not result in hypoglycemia. An overdose may result in transient increases in flatulence, diarrhea, and abdomi-nal discomfort. Because of the lack of extra-intestinal effects seen with miglitol, no serious systemic reactions are expected in the event of an overdose.
Protein Binding: The protein binding of miglitol is negligible (<4.0%).
Biotransformation: Miglitol is not metabolized in man or in any animal species studied.
Half Life: The elimination half-life of miglitol from plasma is approximately 2 hours.
Dosage Forms of Glyset: Tablet Oral
Chemical IUPAC Name: (2R,3R,4R,5S)-1-(2-hydroxyethyl)-2-(hydroxymethyl)piperidine-3,4,5-triol
Chemical Formula: C8H17NO5
Miglitol on Wikipedia: https://en.wikipedia.org/wiki/Miglitol
Organisms Affected: Humans and other mammals