glyburide

glyburide

(glye' byoor ide)

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 mellitus 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; T_1/2: 4 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Bile, 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, weight gain

·        Hematologic: Leukopenia, thrombocytopenia, anemia

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

Interactions

Drug-drug

·        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

Drug-alternative therapy

·        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, serumcreatinine, LFTs, 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.