acarbose

General

Pronunciation:
aye-kar-bose

Trade Name(s)

• Glucobay 
• Precose

Ther. Class.

antidiabetics

Pharm. Class.

alpha glucosidase inhibitors

Indications

Management of type 2 diabetes in conjunction with dietary therapy; may be used with insulin or other hypoglycemic agents.

Action

Lowers blood glucose by inhibiting the enzyme alpha-glucosidase in the GI tract. Delays and reduces glucose absorption.

Therapeutic Effect(s):

Lowering of blood glucose in diabetic patients, especially postprandial hyperglycemia.

Pharmacokinetics

Absorption: <2% systemically absorbed; action is primarily local (in the GI tract).

Distribution: Unknown.

Metabolism and Excretion: Minimal amounts absorbed are excreted by the kidneys.

Half-life: 2 hr.

TIME/ACTION PROFILE (effect on blood glucose)

Contraindication/Precautions

Contraindicated in:

• Hypersensitivity;
• Diabetic ketoacidosis;
• Cirrhosis;
• Serum creatinine >2 mg/dL;
• Lactation:  Lactation.

Use Cautiously in:

• OB:   Safety not established in pregnancy
• Pedi:   Safety and effectiveness not established in children
• Presence of fever, infection, trauma, stress (may cause hyperglycemia, requiring alternative therapy).

Adverse Reactions/Side Effects

GI: abdominal pain, diarrhea, flatulence, ↑ liver enzymes

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

•  Thiazide diuretics  and  loop diuretics,  corticosteroids,  phenothiazines,  thyroid preparations,  estrogens (conjugated),  progestins,  hormonal contraceptives,  phenytoin,  niacin,  sympathomimetics,  calcium channel blockers, and  isoniazid  may ↑ glucose levels in diabetic patients and lead to ↓ control of blood glucose.
• Effects are↓ by  intestinal adsorbents, including  activated charcoal  and  digestive enzyme preparations (amylase, pancreatin) ; avoid concurrent use.
• ↑ effects of  sulfonylurea hypoglycemic agents.
• May ↓ absorption of  digoxin ; may require dosage adjustment.

Drug-Natural Products:

•  Glucosamine  may worsen blood glucose control.
•  Chromium and  coenzyme Q-10  may ↑ hypoglycemic effects.

Route/Dosage

PO (Adults): 25 mg 3 times daily; may ↑ every 4–8 wk as needed/tolerated (range 50–100 mg 3 times daily; not to exceed 50 mg 3 times daily in patients ≤60 kg or 100 mg 3 times daily in patients >60 kg).

Availability (generic available)

Tablets: 25 mg, 50 mg, 100 mg

Assessment

• Observe patient for signs and symptoms of hypoglycemia (sweating, hunger, weakness, dizziness, tremor, tachycardia, anxiety) when taking concurrently with other oral hypoglycemic agents.

Lab Test Considerations:

Monitor serum glucose and glycosylated hemoglobin periodically during therapy to evaluate effectiveness.

• Monitor AST and ALT every 3 mo for the 1st yr and then periodically. Elevated levels may require dose reduction or discontinuation of acarbose. Elevations occur more commonly in patients taking more than 300 mg/day and in female patients. Levels usually return to normal without other evidence of liver injury after discontinuation.

Symptoms of overdose are transient increase in flatulence, diarrhea, and abdominal discomfort. Acarbose alone does not cause hypoglycemia; however, other concurrently administered hypoglycemic agents may produce hypoglycemia requiring treatment.

Implementation

• Patients stabilized on a diabetic regimen who are exposed to stress, fever, trauma, infection, or surgery may require administration of insulin.

  • Does not cause hypoglycemia when taken while fasting, but may increase hypoglycemic effect of other hypoglycemic agents.
• PO Administer with first bite of each meal 3 times/day.

Patient/Family Teaching

• Instruct patient to take acarbose at same time each day. If a dose is missed and the meal is completed without taking the dose, skip missed dose and take next dose with the next meal. Do not double doses.
• Explain to patient that acarbose controls hyperglycemia but does not cure diabetes. Therapy is long-term.
• Review signs of hypoglycemia and hyperglycemia (blurred vision; drowsiness; dry mouth; flushed, dry skin; fruit-like breath odor; increased urination; ketones in urine; loss of appetite; stomachache; nausea or vomiting; tiredness; rapid, deep breathing; unusual thirst; unconsciousness) with patient. If hypoglycemia occurs, advise patient to take a form of oral glucose (e.g., glucose tablets, liquid gel glucose) rather than sugar (absorption of sugar is blocked by acarbose) and notify health care professional.
• Encourage patient to follow prescribed diet, medication, and exercise regimen to prevent hypoglycemic or hyperglycemic episodes.
• Instruct patient in proper testing of serum glucose and urine ketones. Monitor closely during periods of stress or illness. Notify health care professional if significant changes occur.
• Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
• Advise patient to inform health care professional of medication regimen before treatment or surgery.
• Advise patient to carry a form of oral glucose and identification describing disease process and medication regimen at all times.
• Advise female of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
• Emphasize the importance of routine follow-up examinations.

Evaluation/Desired Outcomes

Control of blood glucose levels without the appearance of hypoglycemic or hyperglycemic episodes.