Gattex (Teduglutide) - Subcutaneous

What Is Gattex?

Gattex (teduglutide) is a medicine given by injection to treat a condition called short bowel syndrome (SBS) in adults and children aged 1 year and older. It is used in people who require parenteral support, which involves receiving nutrients via an intravenous infusion of total parenteral nutrition (TPN).

Gattex is very similar to a protein that occurs naturally in your body called human glucagon-like peptide-2 (GLP-2). This substance is released by your intestine when it detects nutrients and slows gastric emptying. This means food moves more slowly through your intestine, giving it more time to absorb nutrients. Gattex also increases blood flow in the intestine, which can help it grow in size.

Gattex is a prescription drug that a healthcare provider needs to prescribe for you. Because Gattex is considered a specialty medication, your insurance company may need to provide special approval before it can be prescribed. You will most likely receive it as a shipment from a specialty pharmacy.

What Is Gattex Used For?

The Food and Drug Administration (FDA) approved Gattex to treat adults and children aged 1 year and older with SBS who are dependent on parenteral support.

SBS occurs when too much of your small intestine is removed or cannot absorb nutrients as it usually does. Your intestine is typically around 20 feet long and absorbs nutrients from food passing through your digestive system.

Sometimes, portions of the small intestine have to be removed due to conditions like Crohn’s disease, internal hernias, damage from cancer, or during gastric bypass surgery. Malnutrition can occur if the small intestine is removed and becomes too short to absorb the nutrients from your food. You may need parenteral support, which involves receiving nutrients via an intravenous infusion of TPN.

How to Take Gattex

Although it can be intimidating or scary to think about having to inject your medicine yourself, the injections required for Gattex are simple and use a tiny needle. Each Gattex kit comes with 30 vials of the drug and 30 prefilled syringes of sterile water that you will add to the drug vials to reconstitute the drug. Reconstitution of the drug is the process that turns it from a powder into liquid before injecting it. The kit also includes alcohol swabs to clean your skin and syringes you will use to draw up the drug and inject it.

Gattex is taken once a day and should ideally be taken at the same time each day.

Before injecting Gattex:

• Wash your hands before you start getting your injection ready.
• Attach the needle to the sterile water syringe, then inject the contents of the syringe into the Gattex drug vial.
• Remove the syringe.
• Gently roll (don’t shake) the vial between your palms to help the mixing process, and then let it stand for about two minutes.
• Wait until all of the powder is dissolved before injecting the drug.

After mixing the water and drug, the vial must be administered within three hours. Take an alcohol swab and clean the area of your skin where you plan to inject Gattex. Grab one of the plastic dosing syringes, and draw up the dose you need to give yourself from the reconstituted drug vial.

The drug is given subcutaneously, which means you will inject the medicine right under your skin instead of into a muscle or a vein. The needles are tiny, only about a quarter of an inch long. Rotate between your thighs, stomach area, or upper arms for subcutaneous injections, as these areas commonly have the most fat. Do not inject into cut, tender, bruised, or scarred skin, and do not inject through clothing.

It may be helpful to visit the Gattex website and view the instructional video overview of the administration process. Ask your healthcare provider if you have any questions or concerns about using the injection.

Storage

Store your Gattex kit at room temperature (up to 77 degrees Fahrenheit). Do not leave your kit out in a hot car or sitting in direct sunlight.

Inject Gattex within three hours after mixing it with the sterile water. Do not store any Gattex you have already mixed; throw away the rest of the vial.

A sharps container will most likely be provided to you by your specialty pharmacy along with the medication. If not, call the specialty pharmacy or ask your local pharmacist about getting a sharps container so that you don’t have loose needles or medicine in your household garbage.

What Are the Side Effects of Gattex?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 1-800-FDA-1088.

Common Side Effects

These are the most common side effects of Gattex. If you experience these side effects and think they are severe or do not go away, you should notify your healthcare provider.

• Nausea
• Vomiting
• Abdominal pain
• Upper respiratory tract infection, including cold-like symptoms such as runny or stuffy nose
• Abdominal distension, or a bloated feeling resulting from gas or fluid building up in your abdomen
• Flatulence or gas
• Appetite disorders, including feeling less hungry than usual
• Cough
  

Severe Side Effects

Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

• Intestinal obstruction. This blockage in your intestine prevents food or liquid from passing through. If you develop an intestinal obstruction, you may need to stop taking Gattex while being treated. You may restart Gattex after the obstruction resolves.
• Gallbladder disease. Within six months before you start Gattex, your healthcare provider should run some lab tests to evaluate your gallbladder function and every six months while you're on it. Two tests called bilirubin and alkaline phosphatase (ALP) will help ensure there are no issues, such as cholelithiasis or cholestasis. 
• Pancreatitis. Similarly, you should also have your lipase and amylase levels checked within six months before starting Gattex and every six months while on it. These tests will help your healthcare provider monitor the function of your pancreas and prevent pancreatitis.
  
  

Dosage: How Much Gattex Should I Take?

Modifications

In some instances, you may need to take precautions while taking or administering this medication.

Pregnancy

Available data from case reports of pregnant individuals taking Gattex have not identified risks of birth defects, miscarriage, or adverse outcomes. Any risk brought by Gattex may outweigh the risk of malnutrition that pregnant women with SBS face, as malnutrition does pose an increased risk of negative effects for the mother and baby.

Breastfeeding

Whether Gattex is present in human breast milk is not well known. Consider the mother’s need for Gattex and weigh its use against any potential risk to the baby.

Age

Gattex has been established as safe and effective for children 1 year and older for treating short bowel syndrome. Additionally, no differences in side effects were seen between younger and older adults (over age 65). However, the trial did not include enough older people to know whether they may be affected differently.

Kidney Problems

The dose of Gattex should be cut in half in children and adults with a glomerular filtration rate (GFR) of less than 60 milliliters/minute/1.73 m2. GFR is a measure of how well your kidneys are working.

Missed Dose

It’s best to give yourself your dose of Gattex at the same time each day. If you miss a dose, take it that same day as soon as you remember. If you realize that you forgot your dose the previous day, just skip it and continue as normal. Do not take two doses of Gattex on the same day.

Overdose: What Happens If I Take Too Much Gattex?

If you only take Gattex as directed, you shouldn’t be concerned about using too much or overdosing. Keep a schedule written down or set reminders on your phone for when doses are due and where you inject them. If you overdose on Gattex, you may need careful monitoring by a healthcare provider.

Precautions

What Are Reasons I Shouldn't Take Gattex?

Gattex may not be the best choice if you have any of the following. Make sure to discuss these with your healthcare provider before starting Gattex:

• A history of cancer. Gattex has the potential to cause hyperplastic changes (or hyperplasia), which means the number of cells increases beyond what is normal. Hyperplasia itself does not mean cancer but may be a precursor to cancer. For this reason, individuals with a history of cancer may need extra monitoring before and while taking Gattex.
• Colorectal polyps. A colonoscopy should be done before starting Gattex to check for polyps or growths in the intestine that have the potential to be cancerous. These will need to be removed and investigated before starting Gattex. A follow-up repeat colonoscopy is recommended after one year of taking Gattex to check for any changes. Stop Gattex if colorectal cancer is diagnosed.
• Issues with your pancreas or gallbladder. Lab testing, including bilirubin, alkaline phosphatase, lipase, and amylase, should be run before and during treatment with Gattex.
• Blood in the stool in children. Children should receive a fecal occult blood test before starting Gattex. If blood is present in the stool, they will likely need a colonoscopy to identify the cause before beginning Gattex.
  

What Other Medications Interact With Gattex?

Similar to how Gattex causes increased absorption of vitamins and nutrients from the food you eat, there is also a potential for increased absorption of other medications you take by mouth, which also pass through your intestine.

Be careful with medicines that require careful dosing and cause side effects, such as pain or anxiety medicines like narcotics or benzodiazepines. You may need a lower dose of these drugs to compensate for the increased absorption that Gattex causes.

What Medications Are Similar?

Gattex is the only drug in its class, but other medicines are used to treat SBS that work in different ways.

• Zorbtive (somatropin) is another injectable medicine used to treat SBS in individuals who rely on parenteral nutrition. It’s similar to a growth hormone normally produced by the pituitary gland that can improve the intestine’s ability to absorb nutrients.
• Drugs like histamine-2 receptor blockers or proton pump inhibitors that are most often used to treat heartburn can also treat SBS. These medications help SBS because they lower excess acid that may further prevent the intestine from absorbing nutrients. Examples include Pepcid (famotidine), Prilosec (omeprazole), and Prevacid (lansoprazole).
• Endari (L-glutamine oral powder) 5-milligram powder for solution is also used to treat SBS.

This is a list of drugs that may also be used to treat short bowel syndrome. Talk with your pharmacist or healthcare provider before you start taking any of these drugs or if you have questions.

How Can I Stay Healthy While Taking Gattex?

Gastrointestinal conditions can be highly frustrating, especially when they necessitate parenteral support. This can interrupt activities of daily living, take up a lot of time for infusions, require frequent adjustments, and decrease the overall quality of life.

Any number of problems can cause the need to remove portions of the small intestine. Crohn’s disease, cancer damage, intestinal injury from loss of blood flow, and other intestinal issues can lead to short bowel syndrome. Fortunately, medications like Gattex can help decrease the number of days individuals have to receive parenteral nutrition.

While it may seem scary at first to be prescribed medicine you inject yourself, many people self-inject medicines under the skin, or subcutaneously, using kits that make the process simple. Being patient, reaching out to family, friends, and your healthcare team for support, and sticking to your dosing schedule will give you the best chance of relying less on parenteral support.