Telotristat belongs to the group of drugs known as tryptophan hydroxylase inhibitors. It is used in combination with other medications to reduce refractory carcinoid syndrome diarrhea, when other treatments have not been effective.

Symptoms of refractory carcinoid syndrome occur when tumours cause excess hormones and other chemical messengers to be formed in the body. When serotonin is over-produced, it can result in severe diarrhea. Telotristat works to reduce the amount of serotonin in the body, thereby reducing the severity of diarrhea associated with refractory carcinoid syndrome.

Telotristat is usually effective within 12 weeks of starting to take the medication.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of telotristat is one 250 mg tablet taken by mouth, 3 times a day.

This medication should be taken with food.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Each white-to-off-white, film-coated, oval tablet with "T-E" debossed on one side and "250" debossed on the other side, contains 250 mg of telotristat ethyl. Nonmedicinal ingredients: croscarmellose sodium, hydroxypropylcellulose, lactose anhydrous, magnesium stearate, silica, colloidal anhydrous. Film-coating: macrogol 3350, polyvinyl alcohol – partially hydrolysed, talc, and titanium dioxide.

Do not take this medication if you are allergic to telotristat or any ingredients of the medication.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• decreased appetite
• dizziness
• dry skin
• fatigue
• fever
• flushing
• gas
• headache
• nausea
• rash
• stomach pain
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal swelling
• constipation
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• swelling of the ankles or feet
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• symptoms of a bowel blockage (e.g., abdominal pain, severe constipation, nausea)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Constipation: Telotristat reduces the frequency at which bowel movements occur. Report symptoms of constipation, such as difficulty passing bowel movements; dry, hard stools; abdominal pain; or infrequent bowel movements to your doctor.

Depression: Serotonin is a body chemical that affects mood. Because telotristat changes how serotonin is used in the body, it may cause mood swings and symptoms of depression. If you have depression or a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking this medication contact your doctor as soon as possible.

Drowsiness/reduced alertness: Telotristat may cause drowsiness or dizziness, affecting your ability to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Liver function: People taking telotristat may have changes in liver function that produce abnormal liver test results. Your doctor will recommend regular liver tests while you are taking this medication. If you have severe changes in liver function, your doctor may recommend that you take a lower dose of this medication or stop taking it altogether.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if telotristat passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between telotristat and any of the following:

• birth control pills (oral contraceptives)
• bupropion
• carbamazepine
• clozapine
• cyclophosphamide
• efavirenz
• methadone
• midazolam
• nimodipine
• octreotide
• sirolimus
• tacrolimus
• triazolam

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.