Liothyronine

Liothyronine
Clinical data
Trade names	Cytomel, Tertroxin, others
AHFS/Drugs.com	Monograph
MedlinePlus	a682462
License data	US DailyMed: Liothyronine;
Routes of; administration	By mouth, intravenous
ATC code	H03AA02 (WHO) ;
Legal status
Legal status	CA: ℞-only; UK: POM (Prescription only);
Pharmacokinetic data
Protein binding	99.7%
Elimination half-life	2.5 days
Identifiers
	IUPAC name (2S)-2-amino-3-[4-(4-hydroxy-3-iodophenoxy)-3,5-diiodophenyl]propanoic acid;
CAS Number	6893-02-3 ;
PubChem CID	5920;
IUPHAR/BPS	2634;
DrugBank	DB00279 ;
ChemSpider	5707 ;
UNII	06LU7C9H1V;
KEGG	D08128;
ChEBI	CHEBI:18258 ;
ChEMBL	ChEMBL1544 ;
PDB ligand	T3 (PDBe, RCSB PDB);
CompTox Dashboard (EPA)	DTXSID8047505 ;
ECHA InfoCard	100.000.203
Chemical and physical data
Formula	C15H12I3NO4
Molar mass	650.977 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES C1=CC(=C(C=C1OC2=C(C=C(C=C2I)C[C@@H](C(=O)O)N)I)I)O;
	InChI InChI=1S/C15H12I3NO4/c16-9-6-8(1-2-13(9)20)23-14-10(17)3-7(4-11(14)18)5-12(19)15(21)22/h1-4,6,12,20H,5,19H2,(H,21,22)/t12-/m0/s1 ; Key:AUYYCJSJGJYCDS-LBPRGKRZSA-N ;
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Liothyronine is a manufactured form of the thyroid hormone triiodothyronine (T₃). It is most commonly used to treat hypothyroidism and myxedema coma. It can be taken by mouth or by injection into a vein.

Side effects may occur from excessive doses. This may include weight loss, fever, headache, anxiety, trouble sleeping, arrhythmias, and heart failure. Use in pregnancy and breastfeeding is generally safe.

Liothyronine was approved for medical use in 1956. It is available as a generic medication. In 2022, it was the 204th most commonly prescribed medication in the United States, with more than 1 million prescriptions.