exenatide (Byetta)

Exenatide is an injectable drug that reduces the level of sugar (glucose) in the blood. It is used for treating type 2 diabetes. Exenatide belongs in a class of drugs called incretin mimetics because these drugs mimic the effects of incretins. Incretins, such as human-glucagon-like peptide-1 (GLP-1), are hormones that are produced and released into the blood by the intestine in response to food. GLP-1 increases the secretion of insulin from the pancreas, slows absorption of glucose from the gut, and reduces the action of glucagon. (Glucagon is a hormone that increases glucose production by the liver.) All three of these actions reduce levels of glucose in the blood. In addition, GLP-1 reduces appetite. Exenatide is a synthetic (man-made) hormone that resembles and acts like GLP-1. In studies, exenatide-treated patients achieved lower blood glucose levels and experienced weight loss. Exenatide was approved by the FDA in May 2005.

What brand names are available for exenatide?

Byetta, Bydureon

Is exenatide available as a generic drug?

No

Do I need a prescription for exenatide?

Yes.

The most common side effects of exenatide are:

• nausea (nausea from exenatide is more common with the higher doses and decreases over time.)
• hypoglycemia (excessively low blood glucose),
• vomiting,
• diarrhea,
• headache,
• nervousness and,
• stomach discomfort.

Other important side effects include:

• decreased appetite,
• acid reflux, and
• increased sweating.

There have been reports of acute pancreatitis associated with the use of exenatide. Patients developing severe, persistent abdominal pain should seek prompt medical attention. If pancreatitis is suspected, exenatide should be discontinued and not started again until pancreatitis has been excluded.

The initial dose of exenatide is 5 mcg injected under the skin (subcutaneously) twice daily, 60 minutes before breakfast or dinner. Exenatide should not be administered after a meal. Each dose should be injected in the thigh, abdomen or upper arm. The dose can be increased to 10 mcg twice daily after 1 month of therapy.

Exenatide slows down transit of food and drugs through the intestine and, therefore, can reduce the absorption of drugs that are taken orally. To avoid this interaction, administer oral medications one hour before exenatide is administered. Orally administered drugs that need to be administered with food should be given with a light meal or snack when exenatide is not administered.

There are no adequate studies of exenatide in pregnant women. Most experts agree that insulin is the drug of choice in pregnant women with diabetes.

There are no adequate studies of exenatide in nursing mothers, and it is not known whether exenatide is excreted in human breast milk.

What preparations of exenatide are available?

Multiple dose pre-filled pen: 1.2 mL, 5 mcg per dose (60 doses) or 2.4 mL, 10 mcg per dose (60 doses)

How should I keep exenatide stored?

Exenatide should be refrigerated between 2-8 C (36-46 F) and protected from light. After first use, it may be stored at room temperature and should not be frozen or used if frozen. The pen should be discarded 30 days after its first use.