telotristat ethyl telotristat ethyl telotristat ethyl (usan, brand name xermelo) is a prodrug of telotristat, which is an inhibitor of tryptophan hydroxylase. it is formulated as telotristat etiprate — a hippurate salt of telotristat ethyl. telotristat ethylclinical datatrade namesxermeloother nameslx1032, lx1606ahfs/drugs.commonographmedlineplusa617029license data us dailymed: telotristat_ethyl pregnancycategory au: b3 routes ofadministrationby mouth (tablets)atc codea16ax15 (who) legal statuslegal status au: s4 (prescription only) ca: ℞-only uk: pom (prescription only) us: ℞-only eu: rx-only pharmacokinetic dataprotein binding>99% (both telotristat ethyl and telotristat)metabolismhydrolysis via carboxylesterasesmetabolitestelotristatelimination half-life0.6 hours (telotristat ethyl), 5 hours (telotristat)excretionfeces (92.8%), urine (less than 0.4%)identifiers iupac name cas number1033805-22-9pubchem cid25181577drugbankdb12095chemspider28189674unii8g388563m7keggd09974as etiprate: d09975chemblchembl2105695chemical and physical dataformulac27h26clf3n6o3molar mass574.99 g·mol−13d model (jsmol)interactive image smiles ccoc(=o)c(cc1=cc=c(c=c1)c2=cc(=nc(=n2)n)oc(c3=c(c=c(c=c3)cl)n4c=cc(=n4)c)c(f)(f)f)n inchi inchi=1s/c27h26clf3n6o3/c1-3-39-25(38)20(32)12-16-4-6-17(7-5-16)21-14-23(35-26(33)34-21)40-24(27(29,30)31)19-9-8-18(28)13-22(19)37-11-10-15(2)36-37/h4-11,13-14,20,24h,3,12,32h2,1-2h3,(h2,33,34,35)/t20-,24+/m0/s1key:mdsqojyhhzbzka-gbxckjpgsa-n on february 28, 2017, the u.s. food and drug administration (fda) approved telotristat ethyl in combination with somatostatin analog (ssa) therapy for the treatment of adults with diarrhea associated with carcinoid syndrome that ssa therapy alone has inadequately controlled. telotristat ethyl was approved for use in the european union in september 2017. the u.s. food and drug administration (fda) considers it to be a first-in-class medication. pharmacology telotristat is an inhibitor of tryptophan hydroxylase, which mediates the rate-limiting step in serotonin biosynthesis. action of telotristat on tryptophan hydroxylase adverse effects common adverse effects noted in clinical trials include nausea, headache, elevated liver enzymes, depression, accumulation of fluid causing swelling (peripheral edema), flatulence, decreased appetite, and fever. constipation is also common, and may be serious or life-threatening (especially in overdose). formulations it is marketed by lexicon pharmaceuticals (as telotristat etiprate). 328 mg telotristat etiprate is equivalent to 250 mg telotristate ethyl. telotristat etiprate