Xermelo (Telotristat Ethyl) - Oral

What Is Xermelo?

Xermelo (telotristat ethyl) is a prescription medication used to treat diarrhea associated with carcinoid syndrome. Approved for adults 18 and older, it's typically used in combination with somatostatin analog (SSA) therapy when the current SSA medication has been deemed insufficient as an independent treatment.

Carcinoid syndrome is caused by slow-growing cancerous tumors, which are usually located in your digestive system.

Xermelo is a tryptophan hydroxylase inhibitor. Tryptophan hydroxylase is a protein that's involved in the production (making) of serotonin. Therefore, by blocking this protein, Xermelo lowers serotonin levels, reducing your diarrhea symptoms.

Not available generically, Xermelo is available as a prescription tablet to be consumed orally (by mouth).

Drug Facts

Generic Name: Telotristat ethyl

Brand Name(s): Xermelo

Drug Availability: Prescription

Therapeutic Classification: Tryptophan hydroxylase inhibitor

Available Generically: No

Controlled Substance: N/A

Administration Route: Oral

Active Ingredient: Telotristat ethyl

Dosage Form(s): Tablet

What Is Xermlo Used For?

The Food and Drug Administration (FDA) has approved Xermelo to treat diarrhea from carcinoid syndrome.

These carcinoid tumors may release certain substances—like serotonin—that result in various symptoms, such as diarrhea. This diarrhea, however, may become excessive and severe, resulting in the following complications:

Serotonin is a naturally occurring chemical in your body that may affect your digestive system. In fact, too much serotonin may result in diarrhea.

In general, carcinoid tumors are rare—with less than 10% of people with these tumors experiencing carcinoid syndrome. For people who develop this syndrome, the tumors typically have spread to the liver.

Xermelo is typically used in combination with an SSA, such as octreotide.

A somatostatin analog is a human-made version of somatostatin (a naturally occurring hormone found in the body). Somatostatins work to slow down the production of hormones, especially serotonin.

Therefore, a somatostatin analog such as octreotide works very similarly to somatostatin. For carcinoid syndrome diarrhea, in particular, octreotide likely works by preventing the release of serotonin.

How to Take Xermelo

Take Xermelo by mouth three times daily with food. If you need short-acting octreotide rescue therapy, make sure that you separate it from Xermelo by 30 minutes.

In fact, Xermelo should be taken 30 minutes before short-acting octreotide.

Stop taking Xermelo and reach out to your healthcare provider if you develop severe constipation or worsening stomach pain that doesn't go away.

Storage

When you receive Xermelo from the pharmacy, keep it at room temperature between 59 degrees F and 86 degrees F.

Keep your medications tightly closed and out of the reach of children and pets, ideally locked in a cabinet or closet. Do not store your medication in the bathroom.

Avoid pouring unused and expired drugs down the drain or in the toilet. Visit the FDA's website to know where and how to discard all unused and expired drugs.

You can also find disposal boxes in your area. Ask your healthcare provider if you have any questions about the best ways to dispose of your medications.

If you plan to travel with Xermelo, get familiar with your final destination's regulations. Checking with the U.S. embassy or consulate might be a helpful resource. In general, however, make a copy of your Xermelo prescription. It's also a good idea to keep your medication in its original container from your pharmacy with your name on the label.

If you have any questions about traveling with your medicine, be sure to ask your healthcare provider.

How Long Does Xermelo Take to Work?

You may notice less diarrhea as early as one to three weeks after first taking Xermelo.

What Are the Side Effects of Xermelo?

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 healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Common side effects with Xermelo may include:

Some people may also have higher gamma-glutamyl transferase (GGT) levels. Since GGT is a protein in your liver, high GGT levels might mean liver damage. The GGT test is typically done with other liver function tests (LFTs) to know for sure.

If you are experiencing worsening liver function, symptoms may include upper right-sided stomach pain, dark urine, and yellowing of the eyes or skin.

Notify your healthcare provider or get medical help right away if you have these symptoms.

Severe Side Effects

Reach out to your healthcare provider right away if the above common side effects don't go away or if you develop the following serious side effects:

  • Severe allergic reaction: If you have a severe allergic reaction to Xermelo, symptoms may include itchiness, swelling, and breathing problems.
  • Severe constipation: Xermelo is supposed to reduce the number of bowel movements (diarrhea episodes or events) that you have. Some people, however, might experience severe constipation or worsening stomach pain that doesn't go away. If you notice these side effects, stop taking Xermelo before immediately contacting your healthcare provider.

Call 911 if your symptoms feel life-threatening.

Long-Term Side Effects

Long-term Xermelo use appears to be safe in people with carcinoid syndrome.

Report Side Effects

Xermelo may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Xermelo Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets)
    • For treatment of carcinoid syndrome diarrhea:
      • Adults—250 milligrams (mg) 3 times a day.
      • Children—Use and dose must be determined by your doctor.

Modifications

The following modifications (changes) should be kept in mind when using Xermelo:

Severe allergic reaction: Avoid using Xermelo if you have a known allergy to it or any of its ingredients. Ask your healthcare provider for a complete list of the ingredients if you're unsure.

Pregnancy: In rat and rabbit animal studies, telotristat ethyl was found to have negative effects on the fetus. We don't know enough about the safety and effectiveness of Xermelo in pregnant people and on the unborn fetus.

Discuss with your healthcare provider if you plan to become pregnant or are pregnant. They will help you weigh the benefits and risks of Xermelo during your pregnancy.

Breastfeeding: We don't know enough about the safety and effects of Xermelo in human breast milk and nursing babies. If you're going to take Xermelo while breastfeeding, you and your healthcare provider may want to monitor your child for constipation symptoms.

Talk with your healthcare provider if you plan to breastfeed. They will help you weigh the benefits and harms of Xermelo while nursing. They can also discuss the different ways available to feed your baby.

Older adults over 65: There are no effectiveness and safety differences between older and younger adults. In general, however, older adults with several medical conditions or who are taking several medications should use caution.

Older adults might be more sensitive to side effects from medications.

Children: There is little safety and effectiveness information available about Xermelo in children.

Kidney problems: No dosage adjustments are necessary if you have mild to severe kidney impairment. Xermelo, however, hasn't been studied in people who are going through dialysis for end-stage renal disease (ESRD).

Liver problems: Individuals with liver problems may not be able to clear the medication from their bodies as easily. This means the medicine stays in the body longer and can have increased side effects.

While it's acceptable to take Xermelo with mild liver impairment, this medication isn't recommended if you have moderate to severe liver impairment.

Missed Dose

If you accidentally forgot your Xermelo dose, then skip the missed dose and take the following dose at your next scheduled dosing time. Don't try to double up to make up for the missed dose.

Try to find ways that work for you to help yourself remember to routinely keep your appointments and take your medication. If you miss too many doses, Xermelo might be less effective.

If you develop severe constipation or worsening stomach pain that doesn't go away, however, stop Xermelo and contact your healthcare provider right away.

Overdose: What Happens If I Take Too Much Xermelo?

There is limited information available about Xermelo overdoses. It's likely that an overdose of Xermelo may exaggerate the medication's side effects, such as severe stomach pain and constipation.

If you think you're experiencing an overdose or life-threatening symptoms, seek immediate medical attention.

What Happens If I Overdose on Xermelo?

If you think you or someone else may have overdosed on Xermelo, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Xermelo, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.

Call your doctor right away if you have severe constipation, or severe persistent or worsening stomach pain after taking this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Xermelo?

Before taking Xermelo, talk with your healthcare provider if any of the following applies to you:

  • Severe allergic reaction: If you have a severe allergic reaction to Xermelo or any of its components (ingredients), this medication isn't a viable option for you.
  • Pregnancy: We don't know enough about the safety and effectiveness of Xermelo in pregnant people and on the unborn fetus. Discuss with your healthcare provider to weigh the benefits and risks of Xermelo during your pregnancy.
  • Breastfeeding: We don't know enough about the safety and effects of Xermelo in human breast milk and nursing babies. If you're going to take Xermelo while breastfeeding, you and your healthcare provider may want to monitor your child for constipation symptoms. Talk with your healthcare provider to weigh the benefits and harms of Xermelo while nursing.
  • Older adults over 65: There are no effectiveness and safety differences between older and younger adults. In general, however, older adults should use caution.
  • Children: There is little safety and effectiveness information available about Xermelo in children.
  • Liver problems: Xermelo is acceptable to take if you have mild liver impairment. This medication, however, isn't recommended if you have moderate to severe liver impairment.

What Other Medications May Interact With Xermelo?

Use caution when taking Xermelo with the following medications:

CYP3A4 and CYP2B6 substrates: CYP3A4 and CYP2B6 are liver proteins that are responsible for breaking down certain medications. Medications that are broken down by these proteins are called substrates. An example of a CYP3A4 substrate is midazolam for seizures and other uses. Wellbutrin (bupropion) for depression is an example of a CYP2B6 substrate.

When taken together, Xermelo may make these proteins quickly break down substrates or medications. This may result in lower levels of these medications and lower effectiveness. Your healthcare provider will likely need to monitor these medications' effects and make any necessary dosage adjustments.

Short-acting octreotide: Short-acting octreotide may reduce Xermelo's levels in your body, lowering Xermelo's effectiveness. To prevent this, use your short-acting octreotide rescue therapy 30 minutes after taking Xermelo.

For more detailed information about medication interactions with Xermelo, talk with your healthcare provider.

Also talk with your healthcare provider about any other medicines you take or plan to take, including over-the-counter (OTC) medications, nonprescription products, vitamins, herbs, or plant-based medicines.

What Medications Are Similar?

Xermelo is the only member of the tryptophan hydroxylase inhibitor medication class. Other medications that are used to treat carcinoid syndrome diarrhea include SSA products.

In fact, SSAs are the initial go-to medications. Xermelo is added on, however, when SSA therapy doesn't help enough.

Frequently Asked Questions

  • Where is Xermelo available?

    Xermelo isn't typically available at your local retail pharmacy. In fact, Xermelo is a specialty medication. Therefore, your healthcare provider may need to send a Xermelo prescription to a specialty pharmacy.

  • How much does Xermelo cost?

    Xermelo isn't available in a generic version. It's also a specialty medication. So, it might be expensive without insurance.

    If cost is a concern, talk to your healthcare provider or a pharmacist about your options. You may be able to reduce costs from a savings program through the manufacturer’s website, as some manufacturers offer copay assistance to make their medication more affordable, or other patient assistance programs.

  • What do I do if I have severe constipation or stomach pain?

    If you're having severe constipation or worsening stomach pain that's not going away, stop taking Xermelo. Make sure to also contact your healthcare provider right away for advice about the next steps.

How Can I Stay Healthy While Taking Xermelo?

If you're taking Xermelo, chances are carcinoid syndrome diarrhea has been negatively affecting your quality of life.

You may have tried different approaches or treatments. While living with carcinoid syndrome diarrhea does have its challenges, there are ways to help improve your quality of life.

Refer below for some general tips to support your health:

  • Take medications as recommended by your healthcare provider.
  • Avoid foods that seem to worsen your diarrhea symptoms, such as foods that are sweet, spicy, fatty, fried, greasy, or high-fiber.
  • Don't chew on sugar-free gum and eat candies or food that have sugar alcohol sweeteners, such as sorbitol, mannitol, or xylitol.
  • Consider foods that are easy on the stomach, such as applesauce, bananas, dry toast, mashed potatoes, and rice.
  • Consider drinks and foods that are high in salt and potassium content.
  • Drink one cup of fluids for each bowel movement (diarrhea episode or event).
  • Drink roughly three quarts (almost three liters) of fluids every day.
  • Consider drinks that are at room temperature, which might be better for your symptoms than cold or hot beverages.
  • Consider the following liquids—water, apple juice, sports drinks, broths, and soups.
  • Don't drink milk or eat milk products, but yogurt and buttermilk might be OK.
  • Don't drink acidic beverages, such as caffeine, tomato juice, or bubbly soft drinks.
  • Keep a journal to record the number of diarrhea episodes that you have.
  • Consider using pads with a plastic backing to prevent dirtying your bed and chairs.
  • Avoid alcohol or tobacco.
  • Clean your anus and surround skin areas with damp (slightly wet) toilet paper or baby wipes to prevent irritation.
  • Apply water-resistant ointments—like petroleum jelly or A&D ointment—to your anus and surrounding skin areas to prevent irritation.
  • Let your healthcare provider know if your anus and surrounding skin areas feel irritated.

Again, these are general tips. Every situation might be different. Talk with your healthcare provider before making any changes.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Ross Phan, PharmD, BCACP, BCGP, BCPS
Ross is a writer for Verywell with years of experience practicing pharmacy in various settings. She is also a board-certified clinical pharmacist and the founder of Off Script Consults.