glyburide

(glye' byoor ide)

Albert Glyburide (CAN), DiaBeta, Euglucon (CAN), Gen-Glybe (CAN), Glibenclamide, Glynase PresTab, Micronase

 

Pregnancy Category B

 

Drug class

Antidiabetic

Sulfonylurea

 

Therapeutic actions

Stimulates insulin release from functioning beta cells in the pancreas; may improve binding between insulin and insulin receptors or increase the number of insulin receptors; more potent in effect than first-generation sulfonylureas.

 

Indications

        Adjunct to diet to lower blood glucose with type 2 (non–insulin-dependent) diabetes mellitus

        Adjunct to metformin when adequate results are not achieved with either drug alone

        Adjunct to insulin therapy in the stabilization of certain cases of type 2 diabetes, reducing the insulin requirement, and decreasing the chance of hypoglycemic reactions

 

Contraindications and cautions

        Contraindicated with allergy to sulfonylureas; diabetes with ketoacidosis, sole therapy of type 1 (insulin-dependent) diabetes or diabetes complicated by pregnancy, serious hepatic or renal impairment, uremia; diabetes complicated by fever, severe infections, severe trauma, major surgery, ketosis, acidosis, coma (insulin is contraindicated).

        Use cautiously with pregnancy, lactation, thyroid or endocrine impairment, glycosuria, hyperglycemia associated with primary renal disease; labor and delivery (if glyburide is used during pregnancy, discontinue drug at least 1 mo before delivery).

 

Available forms

Tablets—1.25, 1.5, 2.5, 3, 4.5, 5, 6 mg

 

Dosages

ADULTS

        Initial therapy: 2.5–5 mg PO with breakfast (DiaBeta, Micronase); 1.5–3 mg/day PO (Glynase).

        Maintenance therapy: 1.25–20 mg/day PO given as a single dose or in divided doses. Increase in increments of no more than 2.5 mg at weekly intervals based on patient's blood glucose response (DiaBeta, Micronase); 0.75–12 mg/day PO (Glynase).

PEDIATRIC PATIENTS

Safety and efficacy not established.

GERIATRIC PATIENTS

Geriatric patients tend to be more sensitive to the drug; start with initial dose of 1.25 mg/day PO (DiaBeta, Micronase) 0.75 mg/day PO (Glynase). Monitor for 24 hr, and gradually increase dose after at least 1 wk as needed.

 

Pharmacokinetics

Route

Onset

Duration

Oral, micronized

1 hr

12–24 hr

Oral, nonmicronized

2–4 hr

12–24 hr

 

Metabolism: Hepatic; T1/2: 4 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Bile and urine

 

Adverse effects

        CNS: Drowsiness, tinnitus, fatigue, asthenia, nervousness, tremor, insomnia

        CV: Increased risk of CV mortality

        Endocrine: Hypoglycemia

        GI: Anorexia, nausea, vomiting, epigastric discomfort, heartburn, diarrhea

        Hematologic: Leukopenia, thrombocytopenia, anemia

        Hypersensitivity: Allergic skin reactions, eczema, pruritus, erythema, urticaria, photosensitivity, fever, eosinophilia, jaundice

 

Interactions

        Increased risk of hypoglycemia with sulfonamides, chloramphenicol, oxyphenbutazone, phenylbutazone, salicylates, clofibrate

        Decreased effectiveness of glyburide and diazoxide if taken concurrently

        Increased risk of hyperglycemia with rifampin, thiazides

        Risk of hypoglycemia and hyperglycemia with ethanol; "disulfiram reaction" has been reported

        Increased risk of hypoglycemia if taken with juniper berries, ginseng, garlic, fenugreek, coriander, dandelion root, celery

 

Nursing considerations

CLINICAL ALERT!

Name confusion has occurred between DiaBeta (glyburide) and Zebeta (bisoprolol); use caution.

 

Assessment

        History: Allergy to sulfonylureas; diabetes with complications; type 1 diabetes, serious hepatic or renal impairment, uremia, thyroid or endocrine impairment, glycosuria, hyperglycemia associated with primary renal disease, pregnancy

        Physical: Skin color, lesions; T; orientation, reflexes, peripheral sensation; R, adventitious sounds; liver evaluation, bowel sounds; urinalysis, BUN, serum creatinine, liver function tests, blood glucose, CBC

 

Interventions

        Give drug before breakfast. If severe GI upset occurs, dose may be divided and given before meals.

        Monitor urine or serum glucose levels frequently to determine drug effectiveness and dosage.

        Monitor dosage carefully if switching to or from Glynase.

        WARNING: Transfer to insulin therapy during periods of high stress (eg, infections, surgery, trauma).

        WARNING: Use IV glucose if severe hypoglycemia occurs as a result of overdose.

 

Teaching points

        Do not discontinue this medication without consulting your health care provider.

        Monitor urine or blood for glucose and ketones.

        Do not use this drug during pregnancy; consult health care provider.

        Avoid alcohol while using this drug.

        Report fever, sore throat, unusual bleeding or bruising, rash, dark urine, light-colored stools, hypoglycemic or hyperglycemic reactions.

 

Adverse effects in Italic are most common; those in Bold are life-threatening.