10 Exenatide Side Effects You Should Know About

Exenatide is a medication that treats Type 2 diabetes. It’s part of a group of medications called glucagon-like peptide-1 agonists (GLP-1 agonists). It works by mimicking GLP-1, a gut hormone involved in controlling blood sugar and digestion. 

Exenatide is available as two injectable name-brand products: Byetta and Bydureon BCise. Byetta is the shorter-acting version of exenatide, and Bydureon BCise is the extended-release version. Byetta is injected twice a day and Bydureon BCise is injected once a week.

Like all medications, exenatide can have side effects. Common side effects are usually mild, but serious (and rare) side effects may require immediate medical attention. Below, we’ll discuss 10 exenatide side effects to be aware of if you’ve been prescribed the medication. But keep in mind, this list is not exhaustive. So talk to your healthcare provider and they can tell you about the risks and benefits of this exenatide.

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1. Nausea and vomiting

Nausea is one of the most common side effects of Byetta and Bydureon BCise. Vomiting is also possible, but it’s less common. 

Nausea and vomiting tend to be more common with Byetta compared to Bydureon BCise. It’s more likely to occur when you first start using the medication or after a dose increase. To help minimize the risk of nausea, Byetta is started at a lower dose and is slowly increased over time. 

Nausea often improves over time as you get used to the medication. Since exenatide can be taken with or without food, try eating smaller meals throughout the day and bland foods if you experience nausea. But if your nausea doesn’t improve, talk with your healthcare provider. If you’re taking Byetta, they may recommend a lower dose. Bydureon BCise is a fixed-dose product, so it’s not possible to lower the dose. If your nausea is severe, your provider may suggest another diabetes medication altogether.

2. Diarrhea

Exenatide may cause diarrhea. This side effect usually improves as your body gets used to the medication. Possible symptoms of diarrhea include loose stools, abdominal pain, and bloating. If you have diarrhea, drink plenty of water to avoid dehydration. 

Diet changes may help manage mild cases of diarrhea. Avoid spicy, fried, or high-fiber foods. Over-the-counter (OTC) antidiarrheal medications, like loperamide (Imodium A-D), may also help. But they should only be used for a few days, and you should talk to your healthcare provider before starting them. 

If diarrhea continues or worsens, let your healthcare provider know. They may recommend another diabetes medication. 

3. Headache

People taking exenatide may experience headaches. Staying hydrated, getting enough sleep, and exercising regularly may help you avoid headaches. Taking an OTC pain reliever like acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) may also help, but talk to your healthcare provider first to make sure it’s safe. 

If you have persistent headaches, or if they worsen over time, let your provider know. This could be a sign that something else is going on. And if your headache is severe, seek emergency help.

4. Dizziness

Exenatide can cause dizziness. This may happen if your blood sugar gets too low (hypoglycemia). 

If you have dizziness while taking exenatide, talk to your healthcare provider. To find out if hypoglycemia is the cause, your provider may ask you to check your blood sugar more often. We’ll talk more about hypoglycemia later.

5. Injection site reactions

Injection site reactions are possible with exenatide. The most common side effect of Bydureon BCise is bumps on the skin after injection. Itching, redness, and bruising can also occur. To lower your risk, inject exenatide in a different area with each dose. You can rotate between your thigh, upper arm, and stomach.

Most injection site reactions are mild and improve after a few days. In rare cases, exenatide can cause more serious injection site reactions. This includes infection, abscess (infected fluid-filled pocket underneath the skin), and necrosis (death of skin or tissues). 

If you experience a mild injection site reaction, you can try a few things to relieve discomfort. For example, an ice pack can help relieve redness or pain that you experience. OTC pain relievers like acetaminophen or ibuprofen may also help. But if the reaction worsens, or lasts longer than a couple days, talk with your healthcare provider. If you notice signs of a serious reaction — including swelling of the face, hives, or severe pain at the injection site — seek emergency care. 

6. Thyroid cancer

Although rare, Bydureon BCise may increase your risk of developing thyroid C-cell tumors. It has a boxed warning — the strongest warning the FDA can give a medication — for this risk. Byetta’s label doesn’t contain this warning.

This side effect has only been seen in animal studies of Bydureon BCise. We don’t know exactly how high the risk is in humans. Still, you should avoid Bydureon BCise if you or someone in your family has had medullary thyroid cancer or multiple endocrine neoplasia type 2 (MEN 2). 

If you’re taking Bydureon BCise and you notice unusual symptoms like a lump in your neck, trouble breathing, or trouble swallowing, contact your healthcare provider right away. 

7. Pancreatitis

Exenatide may cause inflammation of the pancreas (pancreatitis). It’s rare, but it can be life-threatening. 

Especially when you’re starting exenatide or increasing your dose, watch carefully for signs of pancreatitis. These include severe stomach pain (which may extend to the back), vomiting, and trouble eating. You may also experience yellowing of your skin and eyes (jaundice), clammy skin, and fever. If you develop symptoms of pancreatitis, stop exenatide and seek immediate medical attention. 

8. Low blood sugar

The purpose of exenatide is to lower blood sugar. But sometimes, your blood sugar may become too low and cause hypoglycemia. Your risk of hypoglycemia is higher if you take other medications that lower blood sugar, like insulin, or sulfonylureas, like glipizide. If you start exenatide while taking insulin or a sulfonylurea, your healthcare provider may adjust your dose of these medications.

If you take exenatide, you should watch for symptoms of hypoglycemia. Examples include:

• Hunger

• Feeling shaky

• Sweating more than usual

• Anxiety

• Weakness

• Dizziness

• Fast heart rate

Hypoglycemia symptoms often start out mild, so you may not always notice them. If hypoglycemia isn’t treated, severe symptoms — such as passing out, seizures, and even death — can occur. It’s important to monitor your blood sugar regularly at home. This allows you to check for hypoglycemia, even if you aren’t experiencing symptoms.

If you develop symptoms of hypoglycemia, you can treat it quickly by ingesting a fast-acting sugar. Examples include 4 glucose tablets or half a cup of fruit juice or regular soda. Then contact your healthcare provider right away. They’ll let you know if you need to do anything else.

9. Kidney problems

Exenatide can cause kidney problems in some people. The risk is higher if you take other medications that affect kidney function. Examples include ACE inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), and diuretics. The risk of kidney damage is also higher if you have a history of kidney problems. People with severe kidney problems should avoid Byetta and Bydureon BCise.

If you’re taking exenatide, your healthcare provider may monitor your kidney function with blood tests. And it’s a good idea to watch for signs of kidney damage, like peeing less often and leg and ankle swelling (edema). If you experience any of these symptoms, let your healthcare provider know right away.

10. Bleeding problems

In rare cases, exenatide can cause a bleeding problem called drug-induced thrombocytopenia. Thrombocytopenia is when you have low platelet levels in the blood. Platelets are blood cells that stick together after an injury and prevent you from bleeding too much. 

If you don’t have enough platelets, your body will have trouble keeping bleeding to a minimum. Bleeding can occur inside the body or beneath the skin. This can be life-threatening, especially if it happens in the brain.

If you’re taking exenatide, watch for signs of bleeding. This includes long-lasting bleeding after an injury, small red spots under the skin, or bleeding from unusual places like your nose or gums. If you develop symptoms of bleeding while taking exenatide, contact your healthcare provider. And if you have a wound that won’t stop bleeding, seek medical attention immediately. 

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Written by:

Makaela Premont, PharmD

Makaela Premont, PharmD, is a pharmacist and the founder of uniquelymickie.com, a website dedicated to helping pharmacy students and pharmacists create a life that they enjoy. She received her Doctorate of Pharmacy from the University of South Carolina and is a licensed pharmacist in North Carolina.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

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