The FDA has approved Amylin Pharmaceuticals, Inc’s Bydureon (exentatide extended-release for injectable suspension) as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes. Bydureon is an extended-release formulation of Byetta, and the 2 medications should not be used together.1
Bydureon carries a boxed warning regarding its potential risk of thyroid tumors or medullary thyroid carcinoma (MTC). Its approval also carries the following limitations: Bydureon should not be used as first-line therapy for patients whose diabetes is inadequately controlled with diet and exercise, in patients with type 1 diabetes or diabetic ketoacidosis, or in conjunction with insulin, and it should be avoided in patients with a history of pancreatitis, as it has not been studied in this population.
Bydureon is the first once-weekly treatment for type 2 diabetes. Bydureon is approved with a Risk Evaluation and Mitigation Strategy.2
Pharmacology and Pharmacokinetics
Bydureon is a glucagon-like peptide-1 receptor agonist that works to enhance glucose-dependent insulin secretion, suppress inappropriately elevated glucagon secretion, and slow gastric emptying.
Neither race nor gender affected the pharmacokinetics of Bydureon.1
Dosage and Administration
Bydureon should be given as a 2-mg subcutaneous injection every 7 days. It can be administered at any time of day and without regard to meals. The suspension should be injected immediately after mixing. Bydureon should never be given via intravenous or intramuscular injection.1
A 24-week, randomized, open-label trial compared Bydureon with Byetta in 252 patients with type 2 diabetes that was inadequately controlled with diet and exercise alone or with an antidiabetic medication. The mean baseline hemoglobin A1C was 8.4%. Patients received either Bydureon 2 mg subcutaneously once weekly or Byetta 10 mcg subcutaneously twice a day in addition to their preexisting antidiabetic medications. At the study’s end, a statistically significant change in A1C was found: A1C decreased by 1.6 points in the Bydureon group and 0.9 points in the Byetta group.1,2
Contraindications, Warnings, and Precautions
Bydureon carries a boxed warning regarding its potential risk of thyroid tumor or MTC. In rats, Bydureon caused an increased incidence in thyroid C-cell tumors; however, it is unknown if Bydureon causes thyroid C-cell tumors, including MTC, in humans, as human relevance could not be determined by clinical or nonclinical studies.
Bydureon is contraindicated in patients with a personal or family history of MTC and in patients with Multiple Endocrine Neoplasia syndrome type 2. Bydureon is contraindicated in patients with a history of serious hypersensitivity to Bydureon or any of its components.
Postmarketing data have shown Bydureon to be associated with acute pancreatitis, including fatal and nonfatal hemorrhagic or necrotizing pancreatitis. If pancreatitis is suspected, Bydureon should be discontinued immediately and should not be resumed if pancreatitis is confirmed. The risk of hypoglycemia may be increased when Bydureon is used concomitantly with a sulfonylurea and a lower dose of the sulfonylurea may be needed.
Bydureon should not be used in patients with end-stage renal disease or severe renal impairment and should be used cautiously in patients with renal transplantation. Bydureon should not be used in patients with severe gastrointestinal disease. Patients using Bydureon may develop antibodies to it. Serious hypersensitivity reactions have been reported.
Bydureon is Pregnancy Category C and should not be used in women who are pregnant. Bydureon should not be used while breast-feeding. Bydureon is not approved for use in pediatric patients.
Bydureon may reduce the rate of absorption of orally administered medications. Although Bydureon has not been studied with warfarin, there are postmarking reports of increased international normalized ratio (INR) with concomitant use of Byetta and warfarin. Patients using warfarin should have their INR monitored more frequently when Bydureon is initiated. Once a stable INR is documented, patients may resume their previous INR monitoring frequency.
1. Bydureon complete prescribing information. http://documents.bydureon.com/Bydureon_PI.pdf. Accessed May 2012.
2. FDA approves Bydureon – the first and only once-weekly treatment for type 2 diabetes. http://phx.corporate-ir.net/phoenix.zhtml?c=101911&p=irol-newsArticle&ID=1653756&highlight=Bydureon. Accessed May 2012.
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