exenatide acetate

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.