ACARBOSE

(a-car'bose)
Precose
Classifications: hormone and synthetic substitutes; antidiabetic agent; alpha-glucosidase inhibitor
Pregnancy Category: B

Availability

50 mg, 100 mg tablets

Actions

Acarbose is an oral alpha-glucosidase inhibitor. It inhibits or delays the absorption of sugars from the intestinal tract. The inhibitory effect of acarbose varies according to which enzymes are involved; from most to least inhibited are glucoamylase, sucrase, maltase, and isomaltase. Lactase is not affected by acarbose.

Therapeutic Effects

Acarbose reduces blood sugar by interfering with carbohydrate absorption from the GI tract.

Uses

As monotherapy or in combination with a sulfonylurea in patients with type 2 diabetes mellitus.

Unlabeled Uses

In combination with insulin and metformin in patients with type 1 diabetes mellitus.

Contraindications

Inflammatory bowel disease, colon ulcers, partial bowel obstruction, predisposition for obstruction; patients <18 y; lactation.

Cautious Use

GI distress or liver disorders, pregnancy (category B).

Route & Dosage

Diabetes Mellitus
Adult: PO Initiate with 25 mg q.d. to t.i.d. with meals, may increase q4–8wk up to 50–100 mg t.i.d. with meals (max: 150 mg/d for

60 kg, 300 mg/d for >60 kg)

Administration

Oral

Remove drug from foil wrapper immediately before administration.
Give drug with first bite at each of the three main meals.
Do not store above 25° C (77° F). Keep tightly closed and protect from moisture.

Adverse Effects (1%)

CNS: Sleepiness, weakness, dizziness, headache, vertigo (may be due to poor diabetic control). Endocrine: Hypoglycemia (especially in combination with sulfonylureas and insulin). GI: Diarrhea, flatulence, abdominal distention, borborygmi, increased liver function tests. Hematologic: Anemia (especially iron deficiency). Skin: Erythema, exanthema, urticaria.

Interactions

Drug: sulfonylureas may increase hypoglycemic effects. Drugs that induce hyperglycemia (e.g., thiazides, corticosteroids, phenothiazines, estrogens, phenytoin, isoniazid) may decrease effectiveness of acarbose. Herbal: Garlic, ginseng may increase hypoglycemic effects.

Pharmacokinetics

Absorption: Only 0.5–2% is absorbed intact from GI tract. After degradation by intestinal bacteria, up to 35% of dose may be absorbed. Peak: Peak blood glucose reduction approximately 70 min after dose. Metabolism: Metabolized in GI tract by intestinal bacteria and digestive enzymes. Elimination: 35% excreted in urine, 51% excreted in feces, and 5% excreted in air as CO₂. Half-Life: 2 h.

Nursing Implications

Assessment & Drug Effects

Lab tests: Periodically monitor blood glucose, HbA_1C liver, enzymes, Hct and Hgb.
Treat hypoglycemia with dextrose; not with sucrose (table sugar).

Patient & Family Education

Note: Acarbose prevents the breakdown of table sugar. Have a source of dextrose, such as dextrose paste, available to treat low blood sugar.
Monitor closely blood glucose especially following dosage changes.
Report abdominal distress; dietary adjustment or dosage reduction may be warranted.
Monitor weight and report significant changes.
Do not breast feed while taking this drug.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug