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Martindale: The Complete Drug Reference
Liothyronine Sodium
Date of monograph review: 18-Feb-1997; 01-Jun-1998; 06-Apr-2000; 20Jun-2001; 25-Apr-2002; 19-May-2005; 28-Jun-2006; 13-Aug-2008; 22May-2009; 02-Sep-2010; (latest modification: 14-May-2011)
Drug Nomenclature (Latest modification: 20-Apr-2011)
Synonyms: 3,5,3′-Tri-iodo-L-thyronine Sodium; Liothyronin sodná sůl;
Liothyronine sodique; Liothyroninum Natricum; Liotironin Sodyum;
Liotironin-nátrium; Liotironina sódica; Liotironino natrio druska;
Liotyroniininatrium; Liotyronina sodowa; Liotyroninnatrium; Sodium
Liothyronine; L-Tri-iodothyronine Sodium; Tri-iodotironin Sodyum;
リオチロニンナトリウム
BAN: Liothyronine Sodium [BANM]
INN: Liothyronine Sodium [rINNM (en)]
INN: Liotironina sódica [rINNM (es)]
INN: Liothyronine Sodique [rINNM (fr)]
INN: Natrii Liothyroninum [rINNM (la)]
INN: Натрий Лиотиронин [rINNM (ru)]
Chemical name: Sodium 4-O-(4-hydroxy-3-iodophenyl)-3,5-di-iodo-Ltyrosine
Molecular formula: C15H11I3NNaO4 =673.0
CAS: 6893-02-3 (liothyronine); 55-06-1 (liothyronine sodium); 8065-29-0
(liotrix)
ATC code: H03AA02
ATC code (veterinary): QH03AA02
UNII code: GCA9VV7D2N
Martindale code: 9006-d
Martindale: The Complete Drug Reference
Chemical Structure of Liothyronine
NOTE:
The abbreviation T3 is often used for endogenous tri-iodothyronine in medical
and biochemical reports. Liotrix is USAN for a mixture of liothyronine sodium
with levothyroxine sodium.
Pharmacopoeias:
In Eur. (see
), Jpn, and US.
Ph. Eur. 7.2 (Liothyronine Sodium). A white or slightly coloured,
hygroscopic powder. Practically insoluble in water; slightly soluble in alcohol.
It dissolves in dilute solutions of alkali hydroxides. Store at 2 degrees to 8
degrees in airtight containers. Protect from light.
USP 34 (Liothyronine Sodium). A light tan, odourless, crystalline powder.
Very slightly soluble in water; slightly soluble in alcohol; practically insoluble
in most other organic solvents. Store in airtight containers.
Adverse Effects, Treatment, and Precautions (Latest modification: 04Mar-2006)
As for Levothyroxine Sodium,
.
Interactions (Latest modification: 04-Mar-2006)
As for Levothyroxine Sodium,
.
Pharmacokinetics (Latest modification: 04-Mar-2006)
Martindale: The Complete Drug Reference
Liothyronine is readily and almost completely absorbed from the
gastrointestinal tract. Once in the circulation, liothyronine binds principally to
thyroxine-binding globulin (TBG), although less strongly than levothyroxine;
some is also bound to thyroxine-binding pre-albumin (TBPA) or to albumin.
Liothyronine has a plasma half-life in euthyroidism of about 1 to 2 days; the
half-life is prolonged in hypothyroidism and reduced in hyperthyroidism.
Liothyronine is metabolised by deiodination to inactive di-iodothyronine and
mono-iodothyronine. Iodine released by deiodination is largely reused within
the thyroid cells. Further metabolites result from deamination and
decarboxylation to tiratricol (triac).
Uses and Administration (Latest modification: 27-Aug-2010)
Liothyronine is a thyroid hormone (see
hypothyroidism (
). It is used in the treatment of
), and is believed to be more active than levothyroxine (
). The onset of action of liothyronine is rapid, developing within a few
hours, and therefore it tends to be used in circumstances where this, and its
short duration of action, are useful, particularly in hypothyroid (myxoedema)
coma.
With regular dosing the peak therapeutic effect is usually achieved after 3
days; on withdrawal its effects may persist for 1 to 3 days.
The dose of liothyronine should be individualised on the basis of clinical
response and biochemical tests and should be monitored regularly. Although
liothyronine is given as the sodium salt, doses can be expressed in terms of
liothyronine sodium or liothyronine; the doses below are in terms of
liothyronine sodium. Liothyronine sodium 10.3 micrograms is equivalent to
about 10 micrograms of liothyronine. Liothyronine sodium 20 to
25 micrograms is generally considered to be equivalent in activity to about
100 micrograms of levothyroxine sodium.
Martindale: The Complete Drug Reference
In hypothyroidism a usual initial oral dose is 5 to 25 micrograms daily,
increased gradually to a maintenance dose of 60 to 75 micrograms daily in 2
or 3 divided doses, although up to 100 micrograms daily may be required in
some patients. In elderly patients, in those with cardiovascular disorders, or
in those with severe long-standing hypothyroidism, treatment should be
introduced with doses at the low end of the range, with smaller increments,
and longer intervals between increases, as necessary.
In hypothyroid coma liothyronine sodium may be given intravenously in a
dose of 5 to 20 micrograms by slow intravenous injection, repeated as
necessary, usually at intervals of 12 hours; the minimum interval between
doses is 4 hours. An alternative regimen advocates an initial dose of
50 micrograms intravenously followed by further injections of 25 micrograms
every 8 hours until improvement occurs; the dosage may then be reduced to
25 micrograms intravenously twice daily.
For the use of liothyronine in children, see
.
Liothyronine has also been given in the diagnosis of hyperthyroidism in
adults. Failure to suppress the uptake of radio-iodine after several days of
receiving liothyronine sodium suggests a diagnosis of hyperthyroidism.
For use as augmentation treatment with antidepressants, see Depression
under Levothyroxine (
).
Liothyronine hydrochloride has also been used.
Administration in children (Latest modification: 31-Aug-2010)
In the USA, liothyronine sodium may be given orally for the treatment of
congenital hypothyroidism. An initial dose of 5 micrograms daily may be
increased by 5 micrograms every 3 to 4 days, according to response, to the
following usual doses:
Martindale: The Complete Drug Reference
children below 1 year may require 20 micrograms daily
children between 1 to 3 years may require 50 micrograms daily
children over 3 years: as for adults, see
In the UK, liothyronine sodium is unlicensed for use in children. However,
the BNFC 2010/11 recommends that children aged 12 to 18 years may be
given the same dose as adults for the management of hypothyroid coma
(see
).
Preparations (Latest modification: 19-Apr-2011)
Single-ingredient Preparations (Latest modification: 19-Apr-2011)
The symbol ¤ denotes a preparation which is discontinued or no longer
actively marketed.
Australia: Tertroxin; Belgium: Cytomel¤; Brazil: Cynomel¤; Canada:
Cytomel; Czech Republic: Tertroxin¤; France: Cynomel; Germany:
Thybon; Thyrotardin; Greece: Cynomel; T3; Ireland: Tertroxin; Italy:
Dispon¤; Liotir; Ti-Tre; Mexico: Cynomel; Liotrex¤; Triyodisan¤; Triyotex;
Netherlands: Cytomel; New Zealand: Tertroxin; Portugal: NeoTiroimade; South Africa: Tertroxin; Thailand: Tertroxin¤; Turkey:
Tiromel; United Kingdom: Tertroxin¤; Triiodothyronine Injection; United
States: Cytomel; Triostat; Venezuela: Tertroxin¤;
Multi-ingredient Preparations (Latest modification: 20-Apr-2011)
The symbol ¤ denotes a preparation which is discontinued or no longer
actively marketed.
Argentina: Eutroid; Levotrin; Tresite F; Austria: Combithyrex; Novothyral;
Prothyrid¤; Belgium: Novothyral; Brazil: Levotiroxina¤; Tyroplus¤; Chile:
Martindale: The Complete Drug Reference
Novothyral; Czech Republic: Novothyral¤; Thyreotom; France: Euthyral;
Germany: FegaCoren N¤; NeyNormin (Revitorgan-Lingual Nr 65)¤;
NeyNormin N (Revitorgan-Dilutionen N Nr 65)¤; NeyTumorin (RevitorganLingual Nr 66)¤; NeyTumorin N (Revitorgan-Dilutionen N Nr 66)¤;
Novothyral; Prothyrid; Thyreotom¤; Greece: Dithyron; Italy: Tiroide Amsa;
Mexico: Cynoplus; Novotiral; Proloid S¤; Redotex; Poland: Novothyral;
Russia: Novothyral (Новотирал); Thyreocomb (Тиреокомб); Thyreotom
(Тиреотом); South Africa: Diotroxin; Switzerland: Novothyral; Turkey:
Bitiron; United States: Euthroid¤; Thyrolar;
Pharmacopoeial Preparations (Latest modification: 09-Apr-2011)
BP 2011: Liothyronine Tablets; USP 34: Liothyronine Sodium Tablets;
Liotrix Tablets;
Homoeopathic Preparations (Latest modification: 19-Apr-2011)
The symbol ¤ denotes a preparation which is discontinued or no longer
actively marketed.
Germany: AntiFocal N¤; AntiFocal¤; NeyDil 66N (Revitorgan-Dilutionen Nr.
66 N)¤; NeyGeront (Revitorgan-Lingual Nr 64)¤; NeyGeront N (RevitorganDilutionen N Nr 64)¤; NeyGeront Vitalkapsein A; NeyGeront-Vitalkapseln¤;
NeyLing (Revitorgan-Lingual Nr.66)¤;