The timing of exenatide doses is very important. It must be taken between 1 to 60 minutes before a meal. The drug reaches peak effectiveness in about three hours, and its effects taper off by about five hours after injection. If a dose of exenatide is missed or forgotten before starting to eat, it should not be taken during or after the meal. The missed dose should be skipped entirely and the next dose taken as scheduled.
Exenatide is injected just under the skin of the outer thigh, stomach area, or upper arm. Once the needle has been inserted under the skin, the injection button of the pen must be pushed in completely to deliver the drug. To ensure that the full dose of medicine has been delivered, keep the needle inserted and continue pressing the button while counting slowly to five. Because the volume of an exenatide injection is very small, it is unlikely that you would be able to feel when an entire dose had been delivered.
A separate prescription is needed for the pen needles (which can also be used with insulin pens). The following pen needle sizes from various manufacturers are compatible with the exenatide pen: 31 gauge, 3/16 inch; 31 gauge, 1/4 inch; 31 gauge, 5/16 inch; 29 gauge, 1/2 inch. A new needle is needed for each injection. After use, it should be removed and discarded in a puncture-resistant sharps container.
Exenatide pens must be stored in the refrigerator prior to first use. After that, they can be stored at room temperature no higher than 77°F and must be protected from light when not in use. If you need to use your pen away from home in hot weather, carry it in an insulated container to keep it cool. Each pen should be discarded 30 days after first use, even if there is some medicine left in it. A pen should also be discarded if it has been frozen.
You will get the most benefit from exenatide if you use it exactly as prescribed by your health-care provider. In research studies, people who used a 5 µg dose saw an average decrease in glycosylated hemoglobin level (HbA1c) of 0.4% to 0.6%. People who used a 10 µg dose saw an average HbA1c decrease of 0.8% to 0.9%. The HbA1c test is a measure of blood glucose control over 2–3 months. Each 1% drop in HbA1c level reduces the risk of microvascular complications (such as nerve, kidney, and eye disease) by 20% to 30% and reduces the risk of cardiovascular disease by 15% to 20%.
Work with your diabetes care team to be properly trained on how to inject exenatide. Your team can offer suggestions on which pen needle length and gauge is best for you.
Potential side effects. The most common side effect experienced with exenatide is mild to moderate nausea. Nausea is most common when first starting exenatide, but it decreases over time in most people. Other possible side effects include vomiting, diarrhea, feeling jittery, dizziness, headache, and heartburn.
When exenatide is used with a sulfonylurea, mild to moderate hypoglycemia may occur. Often, to reduce the risk of hypoglycemia, health-care providers reduce a person’s dose of the sulfonylurea when starting exenatide.
Precautions. Exenatide may decrease the absorption of some oral medicines such as antibiotics and birth control pills. These medicines should generally be taken at least one hour before the exenatide dose to avoid such an interaction.
Exenatide is not recommended for use in women who are pregnant or breast-feeding. It should not be used by people with severe kidney disease or gastroparesis (slow stomach emptying usually caused by nerve damage). Exenatide does not work the same way as insulin does and should not be used to treat Type 1 diabetes or diabetic ketoacidosis.