Byetta
exenatide acetate
Pharmacologic class: Incretin mimetic
Therapeutic class: Hypoglycemic
Pregnancy risk category C
Action
Enhances glucose-dependent insulin secretion by the pancreatic beta cells, suppresses inappropriately elevated glucagon secretion, and slows gastric emptying
Availability
Solution for injection: 250 mcg/ml as 60 doses in 5-mcg-per-dose/1.2-ml prefilled pen, 250 mcg/ml as 60 doses in 10-mcg-per-dose/2.4-ml prefilled pen
Suspension for injection (extendedrelease): 2 mg/vial
Indications and dosages
➣ Adjunct to diet and exercise to improve glycemic control in patients with type 2 diabetes mellitus
Adults: 5 mcg (Byetta) injected subcutaneously in thigh, abdomen, or upper arm twice daily within 60 minutes before morning and evening meals. Dosage can be increased to 10 mcg after 1 month of therapy, based on clinical response. Or, 2 mg (Bydureon) injected subcutaneously once q 7 days (weekly) at any time of day, with or without meals.
Dosage adjustment
• Concurrent sulfonylurea use (Byetta)
Contraindications
• Hypersensitivity to drug or its components
• Personal or family history of medullary thyroid carcinoma; multiple endocrine neoplasia syndrome type 2 (Bydureon)
Precautions
Use cautiously in:
• severe renal impairment or end-stage renal disease, history of pancreatitis
• severe GI disease (use not recommended)
• type 1 diabetes or diabetic ketoacidosis (avoid use)
• drugs that have narrow therapeutic index or require rapid GI absorption
• concurrent use of insulin (Bydureon use not recommended); concurrent use of prandial insulin (Byetta use not recommended); or concurrent use of other glucose-independent insulin secretagogues (Byetta)
• elderly patients
• pregnant or breastfeeding patients
• children (safety and efficacy not established).
Administration
• Administer oral drugs 1 hour before exenatide. For oral drugs that must be taken with food, administer these with a light meal or snack when exenatide isn't given.
• Discard pen 30 days after first use, even if some drug remains. Don't freeze, and don't use drug if it has been frozen.
• Be aware that Bydureon is intended for patient self-administration and must be administered immediately after powder is suspended.
• Don't coadminister Bydureon and Byetta
Adverse reactions
CNS: dizziness, headache, asthenia, jitteriness
GI: nausea, vomiting, diarrhea, dyspepsia, gastroesophageal reflux disease, acute pancreatitis
Metabolic: hypoglycemia (especially with concurrent sulfonylurea)
Skin: excessive sweating
Other: decreased appetite, general injection site reaction, hypersensitivity reaction
Interactions
Drug-drug. Anti-infectives, hormonal contraceptives: possible slowing of GI transit time
Drug-behaviors. Alcohol use: reduced blood glucose level
Patient monitoring
• Monitor serum glucose level frequently, especially in patients also receiving sulfonylureas.
• Monitor renal function tests periodically.
See Be aware that Bydureon hasn't been studied with warfarin; however, postmarketing reports indicate increased INR, sometimes associated with bleeding, occurs with concomitant use of warfarin and Byetta. Monitor prothrombin time more frequently in patients taking warfarin after starting or altering therapy. Once a stable prothrombin time has been documented, prothrombin times can be monitored at intervals usually recommended for patients on warfarin.
See Be aware that exenatide has been associated with acute pancreatitis, including fatal and nonfatal hemorrhagic or necrotizing pancreatitis. If pancreatitis is suspected, promptly discontinue drug and initiate appropriate management. If pancreatitis is confirmed, don't restart drug.
Patient teaching
• Instruct patient to take Byetta within 1 hour before morning and evening meals meals (or before the two main meals of the day, approximately 6 hours or more apart).
• Teach patient how to self-administer Byetta with prefilled pen. Tell patient to do a new pen set-up one time only, when starting a new prefilled pen. Advise patient to discard pen 30 days after first use, even if some drug remains.
See Instruct patient to inject Bydureon subcutaneously once every 7 days at any time of day, with or without a meal.
See Tell patient that Bydureon is provided in a single-dose tray containing one 2-mg vial of drug, one vial connector, one prefilled diluent syringe, and two needles (one provided as a spare). Instruct patient not to substitute needles or any other components in tray. Tell patient to follow manufacturer's directions precisely for preparing the drug for injection and that the drug must be injected immediately after the powder is suspended in the diluent and transferred to the syringe.
• Caution patient not to freeze drug and not to use it if it has been frozen.
See Teach patient to recognize and immediately report signs and symptoms of hypoglycemia and diabetic ketoacidosis.
See Teach patient how to recognize and to promptly report signs and symptoms of pancreatitis.
• Advise patient to avoid alcohol during therapy.
• Instruct breastfeeding patient to either discontinue breastfeeding or stop taking drug.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and behaviors mentioned above.
exenatide
(ex-en-a-tide) exenatide,Bydureon
(trade name),Byetta
(trade name)Classification
Therapeutic: antidiabeticsPharmacologic: incretin mimetic agents
Indications
Action
Therapeutic effects
Pharmacokinetics
Time/action profile (effects on post-prandial blood glucose)
ROUTE | ONSET | PEAK | DURATION |
---|---|---|---|
Subcut (immediate-release) | within 30 min | 2.1 hr | 8 hr |
Subcut (extended-release) | unknown | 9 wk | unknown |
Contraindications/Precautions
Adverse Reactions/Side Effects
Cardiovascular
- dizziness
- headache
- jitteriness
- weakness
Gastrointestinal
- pancreatitis (life-threatening)
- diarrhea (most frequent)
- nausea (most frequent)
- vomiting (most frequent)
- dyspepsia
- gastroinestinal reflux
Endocrinologic
- thyroid t-cell tumors (extended-release) (life-threatening)
- hypoglycemia
Genitourinary
- acute renal failure
Dermatologic
- hyperhydrosis
Metabolic
- ↓ appetite
- weight loss
Interactions
Drug-Drug interaction
Concurrent use with sulfonylureas or insulin may ↑ risk of hypoglycemia (↓ dose of sulfonylurea or insulin if hypoglycemia occurs); concomitant use of insulin with extended-release exenatide not recommended.Concurrent use with nateglinide or repaglinide may ↑ risk of hypoglycemia.Due to slowed gastric emptying, may ↓ absorption of orally administered medications, especially those requiring rapid GI absorption or require a specific level for efficacy; take oral anti-infectives and oral contraceptives at least 1 hr before injecting exenatide).Route/Dosage
Immediate Release (Byetta)Renal Impairment
Subcutaneous (Adults) CCr 30–50 mL/min—Use caution when ↑ dose from 5 mcg to 10 mcg.Availability
Nursing implications
Nursing assessment
- Observe for signs and symptoms of hypoglycemic reactions (abdominal pain, sweating, hunger, weakness, dizziness, headache, drowsiness, tremor, tachycardia, anxiety, confusion, irritability, jitteriness), especially when combined with oral sulfonylureas.
- Assess for signs and symptoms of pancreatitis (persistent severe abdominal pain, sometimes radiating to the back, may or may not be accompanied by vomiting) at beginning of therapy and with dose increases. If suspected, promptly discontinue therapy and initiate appropriate management. If pancreatitis is confirmed, do not restart exenatide. Consider other antidiabetic therapies in patients with a history of pancreatitis.
- Lab Test Considerations: Monitor serum glucose and glycolysated hemoglobin periodically during therapy to evaluate effectiveness of therapy.
- Monitor renal function prior to and periodically during therapy. Renal dysfunction may be reversed with discontinuation of therapy.
Potential Nursing Diagnoses
Imbalanced nutrition: more than body requirements (Indications)Noncompliance (Patient/Family Teaching)
Implementation
- Some medications may need to be taken 1 hr before exenatide.
- Patients stabilized on a diabetic regimen who are exposed to stress, fever, trauma, infection, or surgery may require administration of insulin.
- Subcutaneous: Immediate release: Follow directions for New Pen Setup in Information for Patient prior to use of each new pen. Inject exenatide in thigh, abdomen, or upper arm at any time within the 60–min period before the morning and evening meals. Do not administer after a meal. Do not mix with insulin. Solution should be clear and colorless; do not administer solutions that are discolored or contain particulate matter. Refrigerate; discard pen 30 days after 1st use, even if some drug remains in pen. Do not freeze. Do not store pen with needle attached; medication may leak from pen or air bubbles may form in the cartridge.
- Subcutaneous: Extended release: Dilute with diluent and needles included in tray. Suspension should be white or off-white and cloudy. Administer without regard to meals. Inject into upper arm, abdomen, or thigh; change site each week. Refrigerate; each tray can be kept at room temperature if not >77°F for up to 4 wks. Do not use beyond expiration date.
Patient/Family Teaching
- Instruct patient to take exenatide immediate release as directed within 60 min before a meal. Do not take after a meal. If a dose is missed, skip the dose and take the next dose at the prescribed time. Do not take an extra dose or increase the amount of the next dose to make up for missed dose. If a dose of exenatide extended release is missed, administer as soon as remembered as long as the next dose is due at least 3 days later; if 1 or 2 days later skip dose and administer next dose as scheduled. The day of weekly administration can be changed as long as the last dose was administered 3 or more days before.
- Instruct patient in proper technique for administration, timing of dose and concurrent oral medications, storage of medication, and disposal of used needles. Patients should read the Information for Patient insert prior to initiation of therapy and with each Rx refill. Advise patient that New Pen Setup should be done only with each new pen, not with each dose.
- Inform patient that pen needles are not included with pen and must be purchased separately. Advise patient which needle length and gauge should be used. Caution patient not to share pen and needles.
- Explain to patient that exenatide helps control hyperglycemia but does not cure diabetes. Therapy is usually long term.
- Encourage patient to follow prescribed diet, medication, and exercise regimen to prevent hyperglycemic or hypoglycemic episodes.
- Review signs of hypoglycemia and hyperglycemia with patient. If hypoglycemia occurs, advise patient to take a glass of orange juice or 2–3 tsp of sugar, honey, or corn syrup dissolved in water, and notify health care professional. Risk of hypoglycemia is increased if sulfonureas are taken concurrently with exenatide.
- Advise patient to notify health care professional immediately if symptoms of pancreatitis (unexplained, persistent, severe abdominal pain which may or may not be accompanied by vomiting) occur.
- Inform patient that therapy may result in reduction of appetite, food intake, and/or body weight. Dose modification is not necessary. Nausea is more common at initiation of therapy and usually decreases over time.
- Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any other Rx, OTC, or herbal products. Exenatide delays stomach emptying. Some medications (such as anti-infectives and oral contraceptives) may need to be taken 1 hr before exenatide injection.
- Instruct patient in proper testing of blood glucose and urine ketones. These tests should be monitored closely during periods of stress or illness and health care professional notified if significant changes occur.
- Advise patient to inform health care professional of medication regimen before treatment or surgery.
- Advise patient to notify health care professional if pregnancy is suspected or planned.
- Advise patient to carry a form of sugar (sugar packets, candy) and identification describing disease process and medication regimen at all times.
- Emphasize the importance of routine follow-up exams and regular testing of blood glucose and glycosylated hemoglobin.
Evaluation/Desired Outcomes
- Control of blood glucose levels without the appearance of hypoglycemic or hyperglycemic episodes.