Liothyronine

Synonyms :
3,3′,5-triiodo-L-thyronine, 3,5,3′-Triiodo-L-thyronine, 3,5,3′-Triiodothyronine, 3,5,3’TRIIODOTHYRONINE, 4-(4-Hydroxy-3-iodophenoxy)-3,5-diiodo-L-phenylalanine, L-3,5,3′-Triiodothyronine, L-T3, Liothyronine, Liothyroninum, Liotironina, O-(4-hydroxy-3-iodophenyl)-3,5-diiodo-L-tyrosine, T3, Tertroxin, Tresitope, Triiodothyronine

Status : approved

Category

Hormone Replacement Agents

Description

The L-triiodothyronine (T3, liothyronine) thyroid hormone is normally synthesized and secreted by the thyroid gland in much smaller quantities than L-tetraiodothyronine (T4, levothyroxine, L-thyroxine). Most T3 is derived from peripheral monodeiodination of T4 at the 5 position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3. [PubChem]

Used

Used as replacement or supplemental therapy in patients with hypothyroidism of any etiology, except transient hypothyrodism during the recovery phase of subacute thyroiditis.

Mechanism Of Action

The hormones, T4 and T3, are tyrosine-based hormones produced by the thyroid gland. Iodine is an important component in their synthesis. The major form of thyroid hormone in the blood is thyroxine (T4). This is converted to the more active liothyronine form by deiodinases in peripheral tissues. Liothyronine acts on the body to increase the basal metabolic rate, affect protein synthesis and increase the body’s sensitivity to catecholamines (such as adrenaline). The thyroid hormones are essential to proper development and differentiation of all cells of the human body. To various extents T4 and T3 regulate protein, fat and carbohydrate metabolism. Their most pronounced effect is on how human cells use energetic compounds. The thyroid hormone derivatives bind to the thyroid hormone receptors initially to initiate their downstream effects.

Dosage

Form Route Strength
Tablet oral 25 mcg
Tablet oral 5 mcg
Injection, solution intravenous 10 ug/mL
Tablet oral 25 ug
Tablet oral 5 ug
Tablet oral 50 1
Tablet oral 50 ug
Tablet oral 12.5; 50 ug/1; ug
Tablet oral 25; 100 ug/1; ug
Tablet oral 3.1; 12.5 ug/1; ug
Tablet oral 37.5; 150 ug/1; ug
Tablet oral 6.25; 25 ug/1; ug
Injection intravenous 10 ug/mL

Pharmacodynamics

Thyroid hormone drugs are natural or synthetic preparations containing T4 or T3 or both. T4 and T3 are produced in the human thyroid gland by the iodination and coupling of the amino acid tyrosine. Liothyronine (T3) contains three atoms of iodine and is formed by the coupling of one molecule of diiodotyrosine (DIT) with one molecule of monoiodotyrosine (MIT). These hormones enhance oxygen consumption by most tissues of the body and increase the basal metabolic rate and the metabolism of carbohydrates, lipids and proteins. Thus, they exert a profound influence on every organ system in the body and are of particular importance in the development of the central nervous system.

Absorption

95% in 4 hours

Half Life

2.5 days

Protein Binding

99.7%

Chemical Classification

This compound belongs to the class of organic compounds known as diphenylethers. These are aromatic compounds containing two benzene rings linked to each other through an ether group.

Diphenylethers

Organic compounds

Benzenoids

Benzene and substituted derivatives

Diphenylethers

Salt : Liothyronine Sodium

Chemical Name

3,3′,5-triiodo-L-thyronine

Brands

name Dosage form Country
Cytomel tablet Canada
Cytomel tablet Canada
Cytomel tablet US
Cytomel tablet US
Cytomel tablet US
Cytomel tablet US
Cytomel tablet US
Cytomel tablet US
Cytomel tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium injection, solution US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Liothyronine Sodium tablet US
Thyrolar tablet US
Thyrolar tablet US
Thyrolar tablet US
Thyrolar tablet US
Thyrolar tablet US
Triostat injection US

Drug Drug Interactions

  •  Carbamazepine  : May decrease the serum concentration of Thyroid Products.
  •  Colesevelam  : May decrease the serum concentration of Thyroid Products.
  •  Fosphenytoin  : May decrease the serum concentration of Thyroid Products. Phenytoin may also displace thyroid hormones from protein binding sites.
  •  Phenytoin  : May decrease the serum concentration of Thyroid Products. Phenytoin may also displace thyroid hormones from protein binding sites.
  •  Polystyrene sulfonate  : May decrease the serum concentration of Thyroid Products.
  •  Polystyrene sulfonate  : May decrease the serum concentration of Thyroid Products.
  •  Rifampicin  : May decrease the serum concentration of Thyroid Products.

Calculated Property

kind Value Source
logP 0.82 ALOGPS
logS -4.5 ALOGPS
Water Solubility 1.95e-02 g/l ALOGPS
logP 2.8 ChemAxon
IUPAC Name (2S)-2-amino-3-[4-(4-hydroxy-3-iodophenoxy)-3,5-diiodophenyl]propanoic acid ChemAxon
Traditional IUPAC Name liothyronine ChemAxon
Molecular Weight 650.9735 ChemAxon
Monoisotopic Weight 650.790038137 ChemAxon
SMILES N[C@@H](CC1=CC(I)=C(OC2=CC(I)=C(O)C=C2)C(I)=C1)C(O)=O ChemAxon
Molecular Formula C15H12I3NO4 ChemAxon
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 ChemAxon
InChIKey InChIKey=AUYYCJSJGJYCDS-LBPRGKRZSA-N ChemAxon
Polar Surface Area (PSA) 92.78 ChemAxon
Refractivity 113.43 ChemAxon
Polarizability 43.92 ChemAxon
Rotatable Bond Count 5 ChemAxon
H Bond Acceptor Count 4 ChemAxon
H Bond Donor Count 3 ChemAxon
pKa (strongest acidic) 0.3 ChemAxon
pKa (strongest basic) 9.48 ChemAxon
Physiological Charge 0 ChemAxon
Number of Rings 2 ChemAxon
Bioavailability 1 ChemAxon
Rule of Five 0 ChemAxon
Ghose Filter 0 ChemAxon
MDDR-Like Rule 0 ChemAxon

Affected organism

Humans and other mammals

Target within organism

  • Thyroid hormone receptor alpha : in Human
  • Thyroid hormone receptor beta : in Human