DrugindexOnline^{2nd edition}

Pronouncation: (mig-LIH-tall)
Class: Alpha-glucosidase inhibitor

Trade Names:
Glyset
- Tablets 25 mg
- Tablets 50 mg
- Tablets 100 mg

Mechanism of Action

Pharmacology

Inhibits intestinal enzymes that digest carbohydrates, thereby reducing carbohydrate digestion after meals, which lowers postprandial glucose elevation in diabetics.

Pharmacokinetics

Absorption

Absorption is saturable at high doses (ie, 25 mg dose is completely absorbed vs 100 mg dose is only 50% to 70% absorbed). T _max is 2 to 3 hr.

Distribution

Distributes primarily into the extracellular fluid. Less than 4% is protein bound and Vd is 0.18 L/kg.

Metabolism

Miglitol is not metabolized.

Elimination

Eliminated by renal excretion as unchanged. More than 95% is recovered in the urine within 24 hr. Plasma t _½ is approximately 2 hr.

Special Populations

Renal Function Impairment

Because miglitol is excreted primarily by the kidneys, accumulation is expected. However, dosage adjustment to correct the increased plasma concentrations is not feasible because miglitol acts locally.

Indications and Usage

Patients with NIDDM who have failed dietary therapy. May be used alone or in combination with sulfonylureas.

Contraindications

Diabetic ketoacidosis; inflammatory bowel disease; colonic ulceration; intestinal disorders of digestion or absorption; partial or predisposition to intestinal obstruction; conditions that may deteriorate as a result of increased intestinal gas production.

Dosage and Administration

Adults

PO 25 mg tid at the start of each meal. After 4 to 8 wk can increase to 50 mg/dose for 3 mo. If glycosylated hemoglobin level not acceptable after 3 mo can increase at 100 mg tid (max dose).

Storage/Stability

Store at room temperature (59° to 86°F) in a tightly closed container, protected from moisture.

Drug Interactions

Intestinal absorbents (eg, charcoal), digestive enzymes

May lower efficacy of miglitol.

Drugs that produce hyperglycemia (eg, corticosteroids, diuretics, thyroid preparations)

May lead to loss of glucose control.

Ranitidine

Reduced ranitidine bioavailability.

Propranolol

Reduced propranolol bioavailability.

Laboratory Test Interactions

Transient decreases in serum iron that are not associated with hemoglobin reduction or other changes in hematologic indices.

Adverse Reactions

Dermatologic

Rash.

GI

Abdominal pain; diarrhea; flatulence.

Precautions

Pregnancy

Category B .

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established.

Renal Function

Miglitol not recommended if serum creatinine is more than 2 mg/dL.

Hypoglycemia

Miglitol does not produce hypoglycemia; however, hypoglycemia may develop if used together with sulfonylureas. Use glucose (dextrose) and not cane sugar (table sugar) or fruits/fruit juices to treat hypoglycemia.

Loss of blood glucose control

Certain medical conditions (eg, surgery, fever, infection, or trauma) and drugs (eg, diuretics, corticosteroids, oral contraceptives) affect glucose control. In these situations, it may be necessary to adjust the dose of miglitol and other antidiabetic drugs.

Overdosage

Symptoms

Increased flatulence, diarrhea, abdominal discomfort.

Patient Information

• Advise patient to take the drug with the first bite of each meal. If necessary, it may be taken during the meal if not taken with the first bite. Do not take after the meal is complete or if skipping a meal.
• Advise patient not to change the dose or dosing interval or discontinue the drug without consulting with health care provider.
• Encourage patient to continue to adhere to a regular exercise program and follow their diabetic meal plan.
• Counsel patient on proper monitoring of blood glucose.
• Advise women of childbearing age that this medication should not be used during pregnancy. Insulin is the preferred agent to control blood glucose.
• Advise patient family that “cane sugar” (sucrose or table sugar) or fruits or fruit juices should not be used to treat hypoglycemic reactions. Glucose (dextrose) or glucagon are necessary to increase blood sugar.
• Advise patient that GI side effects (eg, gas, diarrhea, or abdominal discomfort) usually occur during the first few weeks of therapy but generally go away. Advise patient to inform healthcare provider if these effects persist or become intolerable.