QuickView for thyroxin (compound)

Summary
General Info

PubChem

PubChem Compound 5819

Name:	Thyroxine
PubChem Compound ID:	5819
Description:	The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.
Molecular formula:	C₁₅H₁₁I₄NO₄
Molecular weight:	776.87 g/mol
Synonyms:	Thyroxine (VAN); MLS000028647; 587-29-1; beta-((3,5-Diiodo-4-hydroxyphenoxy)-3,5-diiodophenyl)alanine; Thyratabs; Tyrosine, O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-, labeled with iodine-125; SDCCGMLS-0066571.P001; 4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodo-L-phenylalanine; EINECS 200-101-1; Thyroxine, L- (8CI). show more » Thyroxine (VAN); MLS000028647; 587-29-1; beta-((3,5-Diiodo-4-hydroxyphenoxy)-3,5-diiodophenyl)alanine; Thyratabs; Tyrosine, O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-, labeled with iodine-125; SDCCGMLS-0066571.P001; 4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodo-L-phenylalanine; EINECS 200-101-1; Thyroxine, L- (8CI); CCRIS 6739; T4 (Hormone); KBio3_001642; BRN 2228515; 3,3',5,5'-Tetraiodo-L-thyronine; Thyroxine I 125; AIDS-003357; L-THYROXINE; Prestwick1_000403; 587-30-4; 51-48-9; SPBio_002265; Thryroxine, l-; KBio2_006692; Prestwick0_000403; 7488-70-2; KBioGR_000516; L-T4; Tetraiodothyronine; Thyroxin; L-Tyrosine, O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-; KBio1_001911; Synthroid (Sodium salt); Spectrum2_000573; 24486-40-6; Spectrum4_000128; KBio2_004124; Tetramet; 3,5,3',5'-Tetraiodothyronine; O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-L-tyrosine; 2-amino-3-[4-(4-hydroxy-3,5-diiodo-phenoxy)-3,5-diiodo-phenyl]-propanoic acid; CHEBI:18332; InChI=1/C15H11I4NO4/c16-8-4-7(5-9(17)13(8)21)24-14-10(18)1-6(2-11(14)19)3-12(20)15(22)23/h1-2,4-5,12,21H,3,20H2,(H,22,23; O-(4-Hydroxy-3,5-diidophenyl)-3,5-diiodo-L-tyrosine; 4-14-00-02373 (Beilstein Handbook Reference); AIDS003357; Thyroxine iodine; HSDB 3108; Thyreoideum; 74-16-8; 7200-84-2; Levothroid (Sodium salt); SpecPlus_000871; DivK1c_006967; Spectrum3_000611; Laevothyroxinum (acid); 55-03-8; 3-[4-(4-Hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]-L-alanine; SPBio_000386; NSC 36397; DL-Thyroxin; Thyroxine, labeled with iodine-125; T44; 25416-65-3; 3,5,3',5'-Tetraiodo-L-thyronine; Thyroxine; Synthroid; 3,5,3'5'-Tetraiodo-L-thyronine; L-3,5,3',5'-Tetraiodothyronine; (-)-Thyroxine; Thyroxine (L); Thyroxine I 125 [USAN]; T4; 3,3',5,5''-Tetraiodo-L-thyronine; THX; L-Thyroxin; C01829; Spectrum_001076; Thyrax; Levothyroxin; Levothyroxine; (125I)T4; KBio2_001556; 3-(4-(4-Hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl)alanine; O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodotyrosine; Thyroxinal; Levothyroxinum (acid); Prestwick_548; SMR000059176; KBioSS_001556 show less «

DrugBank

Identification

Name:	Thyroxine
Name (isomeric):	DB00451
Drug Type:	small molecule
Description:	The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.
Synonyms:	L-Thyroxine; Tetraiodothyronine; THX; T4 levothyroxine; Levothyroxin; L-Thryoxin; Levo-t; 3,3',5,5'-Tetraiodo-L-thyronine; Laevothyroxinum; O-(4-Hydroxy-3,5-diidophenyl)-3,5-diiodo-L-tyrosine. show more » L-Thyroxine; Tetraiodothyronine; THX; T4 levothyroxine; Levothyroxin; L-Thryoxin; Levo-t; 3,3',5,5'-Tetraiodo-L-thyronine; Laevothyroxinum; O-(4-Hydroxy-3,5-diidophenyl)-3,5-diiodo-L-tyrosine; (-)-Thyroxine; Thyroxine iodine; Levothyroxine Sodium show less «
Brand:	Thyreoideum, Levothyrox, Thyroxinal, Eltroxin, Laevoxin, Unithroid, Levaxin, Thyroxevan, Thyroxin, Thyrax, Euthyrox, Thyro-tabs, Novothyrox, Oroxine, Synthroid, Levoxine, Synthroid Sodium, Letter, Levolet, Levoxyl, Levothroid, Thyratabs
Brand name mixture:	Liotrix(Levothyroxine + Liothyronine), Thyrolar(Levothyroxine + Liothyronine)
Category:	Antithyroid Agents
CAS number:	51-48-9

Pharmacology

Indication:	For use alone or in combination with antithyroid agents to treat hypothyroidism, goiter, chronic lymphocytic thyroiditis, myxedema coma, and stupor.
Pharmacology:	Levothyroxine (T₄) is a synthetically prepared levo isomer of thyroxine, the major hormone secreted from the thyroid gland. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form triiodothyronine (T₃) which exerts a broad spectrum of stimulatory effect... show more » Levothyroxine (T₄) is a synthetically prepared levo isomer of thyroxine, the major hormone secreted from the thyroid gland. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form triiodothyronine (T₃) which exerts a broad spectrum of stimulatory effects on cell metabolism. Thyroid hormone increases the metabolic rate of cells of all tissues in the body. In the fetus and newborn, thyroid hormone is important for the growth and development of all tissues including bones and the brain. In adults, thyroid hormone helps to maintain brain function, food metabolism, and body temperature, among other effects. The symptoms of thyroid deficiency relieved by levothyroxine include slow speech, lack of energy, weight gain, hair loss, dry thick skin and unusual sensitivity to cold. show less «
Mechanism of Action:	Levothyroxine acts like the endogenous thyroid hormone thyroxine (T₄, a tetra-iodinated tyrosine derivative). In the liver and kidney, T₄ is converted to T₃, the active metabolite. In order to increase solubility, the thyroid hormones attach to thyroid hormone binding proteins, thyroxin-binding globulin, and thyroxi... show more » Levothyroxine acts like the endogenous thyroid hormone thyroxine (T₄, a tetra-iodinated tyrosine derivative). In the liver and kidney, T₄ is converted to T₃, the active metabolite. In order to increase solubility, the thyroid hormones attach to thyroid hormone binding proteins, thyroxin-binding globulin, and thyroxin-binding prealbumin (transthyretin). Transport and binding to thyroid hormone receptors in the cytoplasm and nucleus then takes place. Thus by acting as a replacement for natural thyroxine, symptoms of thyroxine deficiency are relieved. show less «
Absorption:	Bioavailability varies from 48% to 80%. Human studies have confirmed the importance of an intact jejunum and ileum for levothyroxine absorption and have shown some absorption from the duodenum.
Protein binding:	> 99% to serum proteins, including thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), and albumin (TBA)
Biotransformation:	Approximately 70% of secreted T₄ is deiodinated to equal amounts of T₃ and reverse triiodothyronine (rT₃), which is calorigenically inactive. Elimination of T₄ and T₃ involves hepatic conjugation to glucuronic and sulfuric acids. The hormones undergo enterohepatic circulation as conjugates are hydrolyzed in the intestine and reabsorbed. Conjugated compounds that reach the colon are hydrolyzed and eliminated as free compounds in the feces. Other minor T₄ metabolites have been identified.
Route of elimination:	Thyroid hormones are primarily eliminated by the kidneys.
Half Life:	T₄, 6 to 7 days. T₃, 1 to 2 days.
Toxicity:	LD₅₀=20 mg/kg (orally in rat). Hypermetabolic state indistinguishable from thyrotoxicosis of endogenous origin. Symptoms of thyrotoxicosis include weight loss, increased appetite, palpitations, nervousness, diarrhea, abdominal cramps, sweating, tachycardia, increased pulse and blood pressure, cardiac arrhythmias, tremors, insomnia, heat intolerance, fever, and menstrual irregularities.
Affected organisms:	Humans and other mammals

Interactions

Food interaction:

Absorption increased in fasting state and decreased in malabsorption states.

Oral administration with infant soybean formula, soybean flour, cotton seed meal, walnuts, foods containing large amounts of fiber, ferrous sulfate, and antacids may decrease drug absorption.

No iron or calium carbonate within 4 hours of taking this medication.

Take 30-60 minutes before breakfast.

Consistent administration in relation to meals is recommended.

Drug interaction:

Calcium Acetate	Calcium salts such as calcium acetate may diminish the therapeutic effect of thyroid products such as levothyroxine. Separate the doses of the thyroid product and the oral calcium supplement by at least 4 hours. Monitor for decreased therapeutic effects of thyroid products if an oral calcium supplement is initiated/dose increased, or increased effects if an oral calcium supplement is discontinued/dose decreased.
Warfarin	Levothyroxine may contribute to the anticoagulant effect of warfarin by increasing the metabolism of vitamin K-dependent clotting factors. Monitor for changes in prothrombin time and anticoagulant effects if levothyroxine is initiated, discontinued or dose changed.
Colestipol	The resin, colestipol, decreases the absorption of the thyroid hormone, levothyroxine.
Dicumarol	The thyroid hormone, levothyroxine, increase the anticoagulant effect of dicumarol.
Cholestyramine	The resin, cholestyramine, decreases the absorption of the thyroid hormone, levothyroxine.

Targets

Thyroid hormone receptor alpha

Thyroid hormone receptor beta-1

Enzymes

Cytochrome P450 2C8

Cytochrome P450 3A4

Transporters

Solute carrier organic anion transporter family member 1C1

Monocarboxylate transporter 8

Multidrug resistance protein 1

Carriers

Transthyretin

Thyroxine-binding globulin

Serum albumin