Structure via PubChem · Public domain (PubChem)
L-thyroxine
Sign in to saveAlso known as levothyroxine sodium, Levothyroxin, 4-(4-Hydroxy-3,5-diiodophenoxy)-3,5-diiodo-L-phenylalanine, LT4, 3,3',5,5'-Tetraiodo-L-thyronine, Levothyroxine, O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodo-L-tyrosine, T4
Levothyroxine, also known as -thyroxine, is a synthetic form of the thyroid hormone thyroxine (T4). It is used to treat thyroid hormone deficiency (hypothyroidism), including a severe form known as myxedema coma. It may also be used to treat and prevent certain types of thyroid tumors. It is not indicated for weight loss. Levothyroxine is taken orally (by mouth) or given by intravenous injection. Levothyroxine has a half-life of 7.5 days when taken daily, so about six weeks is required for it to reach a steady level in the blood.
Key facts
- Drug.image
- Levothyroxine 200.svg
- Drug.image_class
- skin-invert-image
- Drug.image2
- Levothyroxine-from-xtal-3D-bs-17.png
- Drug.image_class2
- bg-transparent
- Drug.tradename
- Synthroid, Levoxyl, others
- Drug.MedlinePlus
- a682461
- Drug.DailyMedID
- Levothyroxine
- Drug.pregnancy_AU
- A
- Drug.routes_of_administration
- By mouth, intravenous
- Drug.ATC_prefix
- H03
- Drug.ATC_suffix
- AA01
- Drug.legal_AU
- S4
- Drug.legal_CA
- Rx-only
- Drug.legal_US
- Rx only
- Drug.bioavailability
- 40-80%
- Drug.metabolism
- Mainly in the liver, kidneys, brain, and muscles
- Drug.elimination_half life
- ca. 7 days (in hyperthyroidism 3–4 days, in hypothyroidism 9–10 days)
- Drug.excretion
- Feces and urine
via Wikipedia infobox
Chemical data
- Formula
- C15H11I4NO4
- Molecular weight
- 776.87 g/mol
- IUPAC name
- (2S)-2-azaniumyl-3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]propanoate
- SMILES
- C1=C(C=C(C(=C1I)OC2=CC(=C(C(=C2)I)O)I)I)C[C@@H](C(=O)[O-])[NH3+]
- InChIKey
- XUIIKFGFIJCVMT-LBPRGKRZSA-N
- XLogP
- 3
- Polar surface area
- 97.2 Ų
- H-bond donors
- 2
- H-bond acceptors
- 4
- Formal charge
- 0
via PubChem
Wikidata facts
- Mass
- 776.686699832
Show 8 more facts
- isomeric SMILES
- C1=C(C=C(C(=C1I)OC2=CC(=C(C(=C2)I)O)I)I)C[C@@H](C(=O)O)N
- canonical SMILES
- C1=C(C=C(C(=C1I)OC2=CC(=C(C(=C2)I)O)I)I)CC(C(=O)O)N
- MCN code
- 3004.39.81
- chemical formula
- C₁₅H₁₁I₄NO₄
- melting point
- 232
- solubility
- 105
- half-life
- 1
- Commons category
- Levothyroxine
Sources (8)
via Wikidata · CC0
~15 min read
Article
17 sectionsContents
- Medical uses
- 50 and older
- Pregnancy and breastfeeding
- Children
- Contraindications
- Side effects
- Interactions
- Chemistry
- Mechanism of action
- Pharmacokinetics
- History
- Society and culture
- Economics
- Available forms
- Research
- References
- External links
Levothyroxine, also known as -thyroxine, is a synthetic form of the thyroid hormone thyroxine (T4). It is used to treat thyroid hormone deficiency (hypothyroidism), including a severe form known as myxedema coma. It may also be used to treat and prevent certain types of thyroid tumors. It is not indicated for weight loss. Levothyroxine is taken orally (by mouth) or given by intravenous injection. Levothyroxine has a half-life of 7.5 days when taken daily, so about six weeks is required for it to reach a steady level in the blood.
Side effects from excessive doses include weight loss, trouble tolerating heat, sweating, anxiety, trouble sleeping, tremor, and fast heart rate. Use is not recommended in people who have had a recent heart attack. Use during pregnancy has been found to be safe. Dosing should be based on regular measurements of thyroid-stimulating hormone (TSH) and T4 levels in the blood. Much of the effect of levothyroxine is following its conversion to triiodothyronine (T3).