telotristat ethyl


tel-oh-tri-state eth-il

Trade Name(s)

  • Xermelo

Ther. Class.

Pharm. Class.
temporary class tryptophan hydroxylase inhibitors


Carcinoid syndrome diarrhea uncontrolled by treatment with somatostatin analog (with somatostatin analog).


Inhibits tryptophan hydroxylase which reduces production of serotonin and subsequent motility and inflammation in gastrointestinal tract.

Therapeutic Effect(s):

Reduced frequency of carcinoid syndrome diarrhea.


Absorption: Absorption increased with food (especially high-fat meal).

Distribution: Unknown.

Protein Binding: >99%.

Metabolism and Excretion: Telotristat ethyl is metabolized via hydrolysis to active metabolite (telostriat); telotristat is further metabolized in the liver; primarily excreted in feces.

Half-life:  Telotristat ethyl– 0.6 hr;  telotristat– 5 hr.

TIME/ACTION PROFILE (plasma levels)

POunknown0.5–2 hr (telotstriat ethyl); 1–3 hr (telotstriat)8 hr


Contraindicated in:

  • None.

Use Cautiously in:

  • OB:  Safety not established;
  • Lactation: Use only if potential benefit of breast feeding justifies potential risk to the infant; closely monitor infant for constipation;
  • Pedi:  Safety and effectiveness not established.

Adverse Reactions/Side Effects

CNS: headache, depression

CV: peripheral edema

GI: nausea, abdominal pain, constipation, ↓ appetite, flatulence, ↑ liver enzymes

Misc: fever

* CAPITALS indicate life-threatening.
Underline indicate most frequent.



  • May ↓ levels of CYP3A4 substrates, including  midazolam ; may need to ↑ dose of CYP3A4 substrate.
  •  Octreotide  (short-acting) may ↓ levels of telostriat; administer short-acting octreotide ≥30 min before telostriat.


PO  (Adults)  250 mg 3 times daily.


Tablets: 250 mg


  • Assess bowel status prior to and periodically during therapy. Monitor for development of constipation and/or severe, persistent, or worsening abdominal pain. Discontinue telotristat ethyl if severe constipation or severe persistent or worsening abdominal pain occur.

Potential Diagnoses


  • PO  Administer 3 times daily with food. If used in conjunction with octreotide, administer octreotide at least 30 min after telotristat ethyl.

Patient/Family Teaching

  • Instruct patient to take telotristat ethyl as directed. If a dose is missed, omit and take next regularly scheduled dose; do not take 2 doses at same time.
  • Advise patient to discontinue telotristat ethyl if severe constipation occurs.
  • Advise female patient to notify health care professional if pregnancy is planned or suspected or if breast feeding. If breast feeding during therapy, monitor infant for constipation.

Evaluation/Desired Outcomes

Resolution of diarrhea.

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